More robust handling of type errors

Give objects descriptions and context so it is possible to issue warnings instead of fatal errors for attempts to access objects of the wrong type.

More robust handling of type errors
Give objects descriptions and context so it is possible to issue warnings instead of fatal errors for attempts to access objects of the wrong type.
Jay Berkenbilt
1 parent c2e16827
Showing 42 changed files with 1133 additions and 164 deletions
ChangeLog
TODO
include/qpdf/QPDF.hh
include/qpdf/QPDFObject.hh
include/qpdf/QPDFObjectHandle.hh
ispell-words
libqpdf/QPDF.cc
libqpdf/QPDFExc.cc
libqpdf/QPDFObject.cc
libqpdf/QPDFObjectHandle.cc
libqpdf/QPDFTokenizer.cc
libqpdf/QPDF_Array.cc
libqpdf/QPDF_Dictionary.cc
libqpdf/QPDF_Stream.cc
libqpdf/QPDF_linearization.cc
libqpdf/qpdf/QPDF_Array.hh
libqpdf/qpdf/QPDF_Dictionary.hh
libqpdf/qpdf/QPDF_Stream.hh
qpdf/qpdf.testcov
qpdf/qtest/qpdf.test
 2018-02-17  Jay Berkenbilt  <ejb@ql.org>
+	* Major enhancements to handling of type errors within the qpdf
+	library. This fix is intended to eliminate those annoying cases
+	where qpdf would exit with a message like "operation for
+	dictionary object attemped on object of wrong type" without
+	providing any context. Now qpdf keeps enough context to be able to
+	issue a proper warning and to handle such conditions in a sensible
+	way. This should greatly increase the number of bad files that
+	qpdf can recover, and it should make it much easier to figure out
+	what's broken when a file contains errors.
+
 	* Error message fix: replace "file position" with "offset" in
 	error messages that report lexical or parsing errors. Sometimes
 	it's an offset in an object stream or a content stream rather than
 Soon
 ====
- * Consider whether there should be a mode in which QPDFObjectHandle
-   returns nulls for operations on the wrong type instead of asserting
-   the type. The way things are wired up now, this would have to be a
-   global flag. Probably it makes sense to make that be the default
-   behavior and to add a static method in QPDFObjectHandle and
-   command-line flag that enables the stricter behavior globally for
-   easier debugging. For cases where we have enough information to do
-   so, we could still warn when not in strict mode.
-
  * Add method to push inheritable resources to a single page by
    walking up and copying without overwrite.  Above logic will also be
    sufficient to fix the limitation in
@@ -703,7 +703,6 @@ class QPDF
 	PointerHolder<InputSource> input, int objid, int generation,
 	qpdf_offset_t stream_offset);
     QPDFTokenizer::Token readToken(PointerHolder<InputSource>,
-                                   bool allow_bad = false,
                                    size_t max_len = 0);
     QPDFObjectHandle readObjectAtOffset(
@@ -23,6 +23,7 @@
 #define __QPDFOBJECT_HH__
 #include <qpdf/DLL.h>
+#include <qpdf/PointerHolder.hh>
 #include <string>
@@ -32,6 +33,7 @@ class QPDFObjectHandle;
 class QPDFObject
 {
   public:
+    QPDFObject();
     // Objects derived from QPDFObject are accessible through
     // QPDFObjectHandle.  Each object returns a unique type code that
@@ -84,8 +86,27 @@ class QPDFObject
     };
     friend class ObjAccessor;
+    virtual void setDescription(QPDF*, std::string const&);
+    bool getDescription(QPDF*&, std::string&);
+    bool hasDescription();
+
   protected:
     virtual void releaseResolved() {}
+
+  private:
+    QPDFObject(QPDFObject const&);
+    QPDFObject& operator=(QPDFObject const&);
+    class Members
+    {
+        friend class QPDFObject;
+      public:
+        ~Members();
+      private:
+        Members();
+        QPDF* owning_qpdf;
+        std::string object_description;
+    };
+    PointerHolder<Members> m;
 };
 #endif // __QPDFOBJECT_HH__
@@ -398,6 +398,21 @@ class QPDFObjectHandle
     QPDF_DLL
     static QPDFObjectHandle newReserved(QPDF* qpdf);
+    // Provide an owning qpdf and object description. The library does
+    // this automatically with objects that are read from from the
+    // input PDF and with objects that are created programmatically
+    // and inserted into the QPDF by adding them to an array or a
+    // dictionary or creating a new indirect object. Most end user
+    // code will not need to call this. If an object has an owning
+    // qpdf and object description, it enables qpdf to give warnings
+    // with proper context in some cases where it would otherwise
+    // raise exceptions.
+    QPDF_DLL
+    void setObjectDescription(QPDF* owning_qpdf,
+                              std::string const& object_description);
+    QPDF_DLL
+    bool hasObjectDescription();
+
     // Accessor methods.  If an accessor method that is valid for only
     // a particular object type is called on an object of the wrong
     // type, an exception is thrown.
@@ -498,7 +513,7 @@ class QPDFObjectHandle
     // Replace value of key, adding it if it does not exist
     QPDF_DLL
-    void replaceKey(std::string const& key, QPDFObjectHandle const&);
+    void replaceKey(std::string const& key, QPDFObjectHandle);
     // Remove key, doing nothing if key does not exist
     QPDF_DLL
     void removeKey(std::string const& key);
@@ -769,7 +784,10 @@ class QPDFObjectHandle
     };
     friend class ReleaseResolver;
-    // Convenience routine: Throws if the assumption is violated.
+    // Convenience routine: Throws if the assumption is violated. Your
+    // code will be better if you call one of the isType methods and
+    // handle the case of the type being wrong, but these can be
+    // convenient if you have already verified the type.
     QPDF_DLL
     void assertInitialized() const;
@@ -832,10 +850,16 @@ class QPDFObjectHandle
 	QPDF* qpdf, int objid, int generation,
 	QPDFObjectHandle stream_dict, qpdf_offset_t offset, size_t length);
-    void assertType(char const* type_name, bool istype) const;
+    void typeWarning(char const* expected_type,
+                     std::string const& warning);
+    void objectWarning(std::string const& warning);
+    void assertType(char const* type_name, bool istype);
     void dereference();
     void makeDirectInternal(std::set<int>& visited);
     void releaseResolved();
+    static void setObjectDescriptionFromInput(
+        QPDFObjectHandle, QPDF*, std::string const&,
+        PointerHolder<InputSource>, qpdf_offset_t);
     static QPDFObjectHandle parseInternal(
         PointerHolder<InputSource> input,
         std::string const& object_description,
@@ -868,7 +892,7 @@ class QPDFObjectHandle
         bool initialized;
-        QPDF* qpdf;			// 0 for direct object
+        QPDF* qpdf;
         int objid;			// 0 for direct object
         int generation;
         PointerHolder<QPDFObject> obj;
@@ -23,9 +23,11 @@ activatePipelineStack
 ActiveState
 acyclic
 adbe
+addContentTokenFilter
 addPage
 addPageAt
 addPageContents
+addTokenFilter
 addToTable
 adjustAESStreamLength
 admon
@@ -54,6 +56,7 @@ allowPoundAnywhereInName
 allowPrintHighRes
 allowPrintLowRes
 antivirus
+anyBadTokens
 aobjid
 apexcovantage
 api
@@ -71,11 +74,13 @@ argv
 arko
 arko's
 Arora
+arrayOrStreamToStreamArray
 ArtBox
 ascii
 asciiHex
 ASCIIHexDecode
 ASCIIHexDecoder
+asMap
 assertArray
 assertBool
 assertDictionary
@@ -214,12 +219,15 @@ closeObject
 cmath
 cmd
 cmyk
+coalesceContentStreams
+CoalesceProvider
 codepage
 codepoint
 col
 Coldwind
 ColorSpace
 colorspace
+ColorToGray
 com
 compareVersions
 compatbility
@@ -230,6 +238,7 @@ Cond
 config
 conftest
 const
+ContentNormalizer
 contrib
 CopiedStreamDataProvider
 copyEncryptionParameters
@@ -300,6 +309,7 @@ deflateEnd
 deflateInit
 defq
 delphi
+deque
 dereference
 dereferenced
 dest
@@ -411,6 +421,7 @@ esize
 exc
 exe
 exp
+expectInlineImage
 ExtensionLevel
 extern
 fb
@@ -439,6 +450,7 @@ Filespec
 FILETIME
 filetrailer
 filterCompressedObjects
+filterPageContents
 findAndSkipNextEOL
 findAttachmentStreams
 findEndstream
@@ -509,6 +521,7 @@ getCompressibleObjects
 getCompressibleObjGens
 getCount
 getDataChecksum
+getDescription
 getDict
 getDictAsMap
 getEncryptionKey
@@ -562,6 +575,7 @@ getOE
 getOffset
 getOffsetLength
 getOperatorValue
+getOriginalID
 getOwningQPDF
 getP
 getPaddedUserPassword
@@ -626,7 +640,10 @@ handleCode
 handleData
 handleEOF
 handleObject
+handleToken
+hasDescription
 hasKey
+hasObjectDescription
 hb
 hbp
 HCRYPTPROV
@@ -668,6 +685,7 @@ ifeq
 iff
 ifndef
 ifstream
+ignorable
 ijg
 Im
 ImageC
@@ -676,6 +694,7 @@ ImageInverter
 ImageMask
 ImageProvider
 inbuf
+includeIgnorable
 INDOC
 indx
 inf
@@ -720,9 +739,12 @@ iostream
 irdp
 isArray
 isBool
+isDataModified
+isDelimiter
 isDictionary
 isdigit
 isEncrypted
+isIgnorable
 isIndirect
 isInitialized
 isInlineImage
@@ -731,6 +753,7 @@ isLinearized
 isName
 isNull
 isNumber
+isNumeric
 iso
 isOperator
 isOrHasName
@@ -741,10 +764,12 @@ isReal
 isReserved
 isScalar
 isspace
+isSpace
 isStream
 isString
 istream
 istype
+isType
 italicseq
 itemizedlist
 iter
@@ -772,6 +797,7 @@ keyset
 LARGEFILE
 lastnum
 lastreleased
+lastTokenWasBad
 latin
 lbuf
 lc
@@ -839,6 +865,7 @@ malloc
 manualFinish
 Mateusz
 maxEnd
+maxlen
 maxval
 md
 mdash
@@ -933,6 +960,7 @@ NTE
 ntotal
 NUL
 num
+numericValue
 numrange
 nval
 nwalsh
@@ -1007,6 +1035,7 @@ parms
 parsecontent
 parseContentStream
 parseInternal
+parsePageContents
 ParserCallbacks
 parseVersion
 partLen
@@ -1033,6 +1062,9 @@ persistAcrossFinish
 ph
 phe
 php
+pipeContentStreams
+PipelineAccessor
+pipePageContents
 pipeStreamData
 pipeStringAndFinish
 Pkey
@@ -1072,6 +1104,7 @@ procset
 ProcSet
 procsets
 programlisting
+programmatically
 Projet
 prov
 provideRandomData
@@ -1106,6 +1139,7 @@ QPDF&#39;s
 QPDFCONSTANTS
 QPDFExc
 QPDFFake
+QPDFFakeName
 QPDFObject
 QPDFObjectHandle
 QPDFObjectHandle's
@@ -1170,6 +1204,7 @@ ReleaseResolver
 remotesensing
 removeKey
 removePage
+removereplace
 repl
 replaceDict
 replaceFilterData
@@ -1191,6 +1226,7 @@ retested
 reverseResolved
 rf
 rfont
+rg
 rgb
 rhs
 rijndael
@@ -1240,7 +1276,9 @@ setCompressStreams
 setContentNormalization
 setDataKey
 setDecodeLevel
+setDescription
 setDeterministicID
+setDictDescription
 setEncryptionParameters
 setEncryptionParametersInternal
 setExtraHeaderText
@@ -1254,11 +1292,14 @@ setjmp
 setLastObjectDescription
 setLastOffset
 setLinearization
+setLinearizationPass
 setLineBuf
 setMinimumPDFVersion
 setmode
 setNewlineBeforeEndstream
 setO
+setObjectDescription
+setObjectDescriptionFromInput
 setObjectStreamMode
 setObjGen
 setOutputFile
@@ -1268,6 +1309,7 @@ setOutputPipeline
 setOutputStreams
 setPasswordIsHexKey
 setPCLm
+setPipeline
 setprecision
 setPreserveEncryption
 setPreserveUnreferencedObjects
@@ -1277,6 +1319,7 @@ setRandomDataProvider
 setStaticAesIV
 setStaticID
 setStreamDataMode
+setStreamDescription
 setSuppressOriginalObjectIDs
 setSuppressWarnings
 setTrailer
@@ -1329,8 +1372,10 @@ StreamDataProvider
 strerror
 StrF
 stricmp
+StringCounter
 StringDecrypter
 stringprep
+StringReverser
 stripesize
 strlen
 strncmp
@@ -1385,10 +1430,13 @@ tobj
 tobjid
 TODO
 toffset
+TokenFilter
+TokenFilters
 tokenize
 tokenized
 tokenizer
 tokenizing
+tokenTypeName
 toolchain
 Toolchains
 toupper
@@ -1400,6 +1448,7 @@ trimTrailerForWrite
 tt
 turbo
 txt
+typeWarning
 uc
 udata
 UE
@@ -1428,6 +1477,7 @@ unparse
 unparseChild
 unparseObject
 unparseResolved
+unparsing
 unreadCh
 unreferenced
 unresolvable
@@ -106,6 +106,7 @@ QPDF::Members::~Members()
 QPDF::QPDF() :
     m(new Members())
 {
+    m->tokenizer.allowEOF();
 }
 QPDF::~QPDF()
@@ -272,10 +273,10 @@ QPDF::findHeader()
 bool
 QPDF::findStartxref()
 {
-    QPDFTokenizer::Token t = readToken(this->m->file, true);
+    QPDFTokenizer::Token t = readToken(this->m->file);
     if (t == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "startxref"))
     {
-        t = readToken(this->m->file, true);
+        t = readToken(this->m->file);
         if (t.getType() == QPDFTokenizer::tt_integer)
         {
             // Position in front of offset token
@@ -421,7 +422,7 @@ QPDF::reconstruct_xref(QPDFExc&amp; e)
         this->m->file->findAndSkipNextEOL();
         qpdf_offset_t next_line_start = this->m->file->tell();
         this->m->file->seek(line_start, SEEK_SET);
-        QPDFTokenizer::Token t1 = readToken(this->m->file, true, MAX_LEN);
+        QPDFTokenizer::Token t1 = readToken(this->m->file, MAX_LEN);
         qpdf_offset_t token_start =
             this->m->file->tell() - t1.getValue().length();
         if (token_start >= next_line_start)
@@ -440,9 +441,9 @@ QPDF::reconstruct_xref(QPDFExc&amp; e)
             if (t1.getType() == QPDFTokenizer::tt_integer)
             {
                 QPDFTokenizer::Token t2 =
-                    readToken(this->m->file, true, MAX_LEN);
+                    readToken(this->m->file, MAX_LEN);
                 QPDFTokenizer::Token t3 =
-                    readToken(this->m->file, true, MAX_LEN);
+                    readToken(this->m->file, MAX_LEN);
                 if ((t2.getType() == QPDFTokenizer::tt_integer) &&
                     (t3 == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "obj")))
                 {
@@ -1429,7 +1430,7 @@ bool
 QPDF::findEndstream()
 {
     // Find endstream or endobj. Position the input at that token.
-    QPDFTokenizer::Token t = readToken(this->m->file, true, 20);
+    QPDFTokenizer::Token t = readToken(this->m->file, 20);
     if ((t.getType() == QPDFTokenizer::tt_word) &&
         ((t.getValue() == "endobj") ||
          (t.getValue() == "endstream")))
@@ -1522,11 +1523,10 @@ QPDF::recoverStreamLength(PointerHolder&lt;InputSource&gt; input,
 }
 QPDFTokenizer::Token
-QPDF::readToken(PointerHolder<InputSource> input,
-                bool allow_bad, size_t max_len)
+QPDF::readToken(PointerHolder<InputSource> input, size_t max_len)
 {
     return this->m->tokenizer.readToken(
-        input, this->m->last_object_description, allow_bad, max_len);
+        input, this->m->last_object_description, true, max_len);
 }
 QPDFObjectHandle
@@ -1730,16 +1730,10 @@ QPDF::resolve(int objid, int generation)
     }
     ResolveRecorder rr(this, og);
-    if (! this->m->obj_cache.count(og))
+    // PDF spec says unknown objects resolve to the null object.
+    if ((! this->m->obj_cache.count(og)) && this->m->xref_table.count(og))
     {
-	if (! this->m->xref_table.count(og))
-	{
-	    // PDF spec says unknown objects resolve to the null object.
-	    return new QPDF_Null;
-	}
-
 	QPDFXRefEntry const& entry = this->m->xref_table[og];
-        bool success = false;
         try
         {
             switch (entry.getType())
@@ -1768,7 +1762,6 @@ QPDF::resolve(int objid, int generation)
                               QUtil::int_to_string(generation) +
                               " has unexpected xref entry type");
             }
-            success = true;
         }
         catch (QPDFExc& e)
         {
@@ -1782,16 +1775,24 @@ QPDF::resolve(int objid, int generation)
                          QUtil::int_to_string(generation) +
                          ": error reading object: " + e.what()));
         }
-        if (! success)
-        {
-            QTC::TC("qpdf", "QPDF resolve failure to null");
-            QPDFObjectHandle oh = QPDFObjectHandle::newNull();
-            this->m->obj_cache[og] =
-                ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1);
-        }
+    }
+    if (this->m->obj_cache.count(og) == 0)
+    {
+        QTC::TC("qpdf", "QPDF resolve failure to null");
+        QPDFObjectHandle oh = QPDFObjectHandle::newNull();
+        this->m->obj_cache[og] =
+            ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1);
     }
-    return this->m->obj_cache[og].object;
+    PointerHolder<QPDFObject> result(this->m->obj_cache[og].object);
+    if (! result->hasDescription())
+    {
+        result->setDescription(
+            this,
+            "object " + QUtil::int_to_string(objid) + " " +
+            QUtil::int_to_string(generation));
+    }
+    return result;
 }
 void
@@ -32,7 +32,10 @@ QPDFExc::createWhat(std::string const&amp; filename,
     }
     if (! (object.empty() && offset == 0))
     {
-	result += " (";
+        if (! filename.empty())
+        {
+            result += " (";
+        }
 	if (! object.empty())
 	{
 	    result += object;
@@ -45,7 +48,10 @@ QPDFExc::createWhat(std::string const&amp; filename,
 	{
 	    result += "offset " + QUtil::int_to_string(offset);
 	}
-	result += ")";
+        if (! filename.empty())
+        {
+            result += ")";
+        }
     }
     if (! result.empty())
     {
 #include <qpdf/QPDFObject.hh>
+
+QPDFObject::Members::Members() :
+    owning_qpdf(0)
+{
+}
+
+QPDFObject::Members::~Members()
+{
+}
+
+QPDFObject::QPDFObject() :
+    m(new Members)
+{
+}
+
+void
+QPDFObject::setDescription(QPDF* qpdf, std::string const& description)
+{
+    this->m->owning_qpdf = qpdf;
+    this->m->object_description = description;
+}
+
+bool
+QPDFObject::getDescription(QPDF*& qpdf, std::string& description)
+{
+    qpdf = this->m->owning_qpdf;
+    description = this->m->object_description;
+    return this->m->owning_qpdf;
+}
+
+bool
+QPDFObject::hasDescription()
+{
+    return this->m->owning_qpdf;
+}
@@ -190,6 +190,18 @@ QPDFObjectHandle::releaseResolved()
     }
 }
+void
+QPDFObjectHandle::setObjectDescriptionFromInput(
+    QPDFObjectHandle object, QPDF* context,
+    std::string const& description, PointerHolder<InputSource> input,
+    qpdf_offset_t offset)
+{
+    object.setObjectDescription(
+        context,
+        input->getName() + ", " + description +
+        " at offset " + QUtil::int_to_string(offset));
+}
+
 bool
 QPDFObjectHandle::isInitialized() const
 {
@@ -282,7 +294,8 @@ QPDFObjectHandle::getNumericValue()
     }
     else
     {
-	throw std::logic_error("getNumericValue called for non-numeric object");
+        typeWarning("number", "returning 0");
+        QTC::TC("qpdf", "QPDFObjectHandle numeric non-numeric");
     }
     return result;
 }
@@ -363,8 +376,16 @@ QPDFObjectHandle::isScalar()
 bool
 QPDFObjectHandle::getBoolValue()
 {
-    assertBool();
-    return dynamic_cast<QPDF_Bool*>(m->obj.getPointer())->getVal();
+    if (isBool())
+    {
+        return dynamic_cast<QPDF_Bool*>(m->obj.getPointer())->getVal();
+    }
+    else
+    {
+        typeWarning("boolean", "returning false");
+        QTC::TC("qpdf", "QPDFObjectHandle boolean returning false");
+        return false;
+    }
 }
 // Integer accessors
@@ -372,8 +393,16 @@ QPDFObjectHandle::getBoolValue()
 long long
 QPDFObjectHandle::getIntValue()
 {
-    assertInteger();
-    return dynamic_cast<QPDF_Integer*>(m->obj.getPointer())->getVal();
+    if (isInteger())
+    {
+        return dynamic_cast<QPDF_Integer*>(m->obj.getPointer())->getVal();
+    }
+    else
+    {
+        typeWarning("integer", "returning 0");
+        QTC::TC("qpdf", "QPDFObjectHandle integer returning 0");
+        return 0;
+    }
 }
 // Real accessors
@@ -381,8 +410,16 @@ QPDFObjectHandle::getIntValue()
 std::string
 QPDFObjectHandle::getRealValue()
 {
-    assertReal();
-    return dynamic_cast<QPDF_Real*>(m->obj.getPointer())->getVal();
+    if (isReal())
+    {
+        return dynamic_cast<QPDF_Real*>(m->obj.getPointer())->getVal();
+    }
+    else
+    {
+        typeWarning("real", "returning 0.0");
+        QTC::TC("qpdf", "QPDFObjectHandle real returning 0.0");
+        return "0.0";
+    }
 }
 // Name accessors
@@ -390,8 +427,16 @@ QPDFObjectHandle::getRealValue()
 std::string
 QPDFObjectHandle::getName()
 {
-    assertName();
-    return dynamic_cast<QPDF_Name*>(m->obj.getPointer())->getName();
+    if (isName())
+    {
+        return dynamic_cast<QPDF_Name*>(m->obj.getPointer())->getName();
+    }
+    else
+    {
+        typeWarning("name", "returning dummy name");
+        QTC::TC("qpdf", "QPDFObjectHandle name returning dummy name");
+        return "/QPDFFakeName";
+    }
 }
 // String accessors
@@ -399,15 +444,31 @@ QPDFObjectHandle::getName()
 std::string
 QPDFObjectHandle::getStringValue()
 {
-    assertString();
-    return dynamic_cast<QPDF_String*>(m->obj.getPointer())->getVal();
+    if (isString())
+    {
+        return dynamic_cast<QPDF_String*>(m->obj.getPointer())->getVal();
+    }
+    else
+    {
+        typeWarning("string", "returning empty string");
+        QTC::TC("qpdf", "QPDFObjectHandle string returning empty string");
+        return "";
+    }
 }
 std::string
 QPDFObjectHandle::getUTF8Value()
 {
-    assertString();
-    return dynamic_cast<QPDF_String*>(m->obj.getPointer())->getUTF8Val();
+    if (isString())
+    {
+        return dynamic_cast<QPDF_String*>(m->obj.getPointer())->getUTF8Val();
+    }
+    else
+    {
+        typeWarning("string", "returning empty string");
+        QTC::TC("qpdf", "QPDFObjectHandle string returning empty utf8");
+        return "";
+    }
 }
 // Operator and Inline Image accessors
@@ -415,15 +476,31 @@ QPDFObjectHandle::getUTF8Value()
 std::string
 QPDFObjectHandle::getOperatorValue()
 {
-    assertOperator();
-    return dynamic_cast<QPDF_Operator*>(m->obj.getPointer())->getVal();
+    if (isOperator())
+    {
+        return dynamic_cast<QPDF_Operator*>(m->obj.getPointer())->getVal();
+    }
+    else
+    {
+        typeWarning("operator", "returning fake value");
+        QTC::TC("qpdf", "QPDFObjectHandle operator returning fake value");
+        return "QPDFFAKE";
+    }
 }
 std::string
 QPDFObjectHandle::getInlineImageValue()
 {
-    assertInlineImage();
-    return dynamic_cast<QPDF_InlineImage*>(m->obj.getPointer())->getVal();
+    if (isInlineImage())
+    {
+        return dynamic_cast<QPDF_InlineImage*>(m->obj.getPointer())->getVal();
+    }
+    else
+    {
+        typeWarning("inlineimage", "returning empty data");
+        QTC::TC("qpdf", "QPDFObjectHandle inlineimage returning empty data");
+        return "";
+    }
 }
 // Array accessors
@@ -431,22 +508,66 @@ QPDFObjectHandle::getInlineImageValue()
 int
 QPDFObjectHandle::getArrayNItems()
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->getNItems();
+    if (isArray())
+    {
+        return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->getNItems();
+    }
+    else
+    {
+        typeWarning("array", "treating as empty");
+        QTC::TC("qpdf", "QPDFObjectHandle array treating as empty");
+        return 0;
+    }
 }
 QPDFObjectHandle
 QPDFObjectHandle::getArrayItem(int n)
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->getItem(n);
+    QPDFObjectHandle result;
+    if (isArray() && (n < getArrayNItems()) && (n >= 0))
+    {
+        result = dynamic_cast<QPDF_Array*>(m->obj.getPointer())->getItem(n);
+    }
+    else
+    {
+        result = newNull();
+        if (isArray())
+        {
+            objectWarning("returning null for out of bounds array access");
+            QTC::TC("qpdf", "QPDFObjectHandle array bounds");
+        }
+        else
+        {
+            typeWarning("array", "returning null");
+            QTC::TC("qpdf", "QPDFObjectHandle array null for non-array");
+        }
+        QPDF* context = 0;
+        std::string description;
+        if (this->m->obj->getDescription(context, description))
+        {
+            result.setObjectDescription(
+                context,
+                description +
+                " -> null returned from invalid array access");
+        }
+    }
+    return result;
 }
 std::vector<QPDFObjectHandle>
 QPDFObjectHandle::getArrayAsVector()
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->getAsVector();
+    std::vector<QPDFObjectHandle> result;
+    if (isArray())
+    {
+        result = dynamic_cast<QPDF_Array*>(m->obj.getPointer())->getAsVector();
+    }
+    else
+    {
+        typeWarning("array", "treating as empty");
+        QTC::TC("qpdf", "QPDFObjectHandle array treating as empty vector");
+    }
+    return result;
 }
 // Array mutators
@@ -454,36 +575,79 @@ QPDFObjectHandle::getArrayAsVector()
 void
 QPDFObjectHandle::setArrayItem(int n, QPDFObjectHandle const& item)
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->setItem(n, item);
+    if (isArray())
+    {
+        dynamic_cast<QPDF_Array*>(m->obj.getPointer())->setItem(n, item);
+    }
+    else
+    {
+        typeWarning("array", "ignoring attempt to set item");
+        QTC::TC("qpdf", "QPDFObjectHandle array ignoring set item");
+    }
 }
 void
 QPDFObjectHandle::setArrayFromVector(std::vector<QPDFObjectHandle> const& items)
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->setFromVector(items);
+    if (isArray())
+    {
+        dynamic_cast<QPDF_Array*>(m->obj.getPointer())->setFromVector(items);
+    }
+    else
+    {
+        typeWarning("array", "ignoring attempt to replace items");
+        QTC::TC("qpdf", "QPDFObjectHandle array ignoring replace items");
+    }
 }
 void
 QPDFObjectHandle::insertItem(int at, QPDFObjectHandle const& item)
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->insertItem(at, item);
+    if (isArray())
+    {
+        dynamic_cast<QPDF_Array*>(m->obj.getPointer())->insertItem(at, item);
+    }
+    else
+    {
+        typeWarning("array", "ignoring attempt to insert item");
+        QTC::TC("qpdf", "QPDFObjectHandle array ignoring insert item");
+    }
 }
 void
 QPDFObjectHandle::appendItem(QPDFObjectHandle const& item)
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->appendItem(item);
+    if (isArray())
+    {
+        dynamic_cast<QPDF_Array*>(m->obj.getPointer())->appendItem(item);
+    }
+    else
+    {
+        typeWarning("array", "ignoring attempt to append item");
+        QTC::TC("qpdf", "QPDFObjectHandle array ignoring append item");
+    }
 }
 void
 QPDFObjectHandle::eraseItem(int at)
 {
-    assertArray();
-    return dynamic_cast<QPDF_Array*>(m->obj.getPointer())->eraseItem(at);
+    if (isArray() && (at < getArrayNItems()) && (at >= 0))
+    {
+        dynamic_cast<QPDF_Array*>(m->obj.getPointer())->eraseItem(at);
+    }
+    else
+    {
+        if (isArray())
+        {
+            objectWarning("ignoring attempt to erase out of bounds array item");
+            QTC::TC("qpdf", "QPDFObjectHandle erase array bounds");
+        }
+        else
+        {
+            typeWarning("array", "ignoring attempt to erase item");
+            QTC::TC("qpdf", "QPDFObjectHandle array ignoring erase item");
+        }
+    }
 }
 // Dictionary accessors
@@ -491,29 +655,79 @@ QPDFObjectHandle::eraseItem(int at)
 bool
 QPDFObjectHandle::hasKey(std::string const& key)
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->hasKey(key);
+    if (isDictionary())
+    {
+        return dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->hasKey(key);
+    }
+    else
+    {
+        typeWarning("dictionary",
+                    "returning false for a key containment request");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary false for hasKey");
+        return false;
+    }
 }
 QPDFObjectHandle
 QPDFObjectHandle::getKey(std::string const& key)
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->getKey(key);
+    QPDFObjectHandle result;
+    if (isDictionary())
+    {
+        result = dynamic_cast<QPDF_Dictionary*>(
+            m->obj.getPointer())->getKey(key);
+    }
+    else
+    {
+        typeWarning(
+            "dictionary", "returning null for attempted key retrieval");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary null for getKey");
+        result = newNull();
+        QPDF* qpdf = 0;
+        std::string description;
+        if (this->m->obj->getDescription(qpdf, description))
+        {
+            result.setObjectDescription(
+                qpdf,
+                description +
+                " -> null returned from getting key " +
+                key + " from non-Dictionary");
+        }
+    }
+    return result;
 }
 std::set<std::string>
 QPDFObjectHandle::getKeys()
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->getKeys();
+    std::set<std::string> result;
+    if (isDictionary())
+    {
+        result = dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->getKeys();
+    }
+    else
+    {
+        typeWarning("dictionary", "treating as empty");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary empty set for getKeys");
+    }
+    return result;
 }
 std::map<std::string, QPDFObjectHandle>
 QPDFObjectHandle::getDictAsMap()
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->getAsMap();
+    std::map<std::string, QPDFObjectHandle> result;
+    if (isDictionary())
+    {
+        result = dynamic_cast<QPDF_Dictionary*>(
+            m->obj.getPointer())->getAsMap();
+    }
+    else
+    {
+        typeWarning("dictionary", "treating as empty");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary empty map for asMap");
+    }
+    return result;
 }
 // Array and Name accessors
@@ -551,27 +765,48 @@ QPDFObjectHandle::getOwningQPDF()
 void
 QPDFObjectHandle::replaceKey(std::string const& key,
-			    QPDFObjectHandle const& value)
+			    QPDFObjectHandle value)
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(
-	m->obj.getPointer())->replaceKey(key, value);
+    if (isDictionary())
+    {
+        dynamic_cast<QPDF_Dictionary*>(
+            m->obj.getPointer())->replaceKey(key, value);
+    }
+    else
+    {
+        typeWarning("dictionary", "ignoring key replacement request");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary ignoring replaceKey");
+    }
 }
 void
 QPDFObjectHandle::removeKey(std::string const& key)
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->removeKey(key);
+    if (isDictionary())
+    {
+        dynamic_cast<QPDF_Dictionary*>(m->obj.getPointer())->removeKey(key);
+    }
+    else
+    {
+        typeWarning("dictionary", "ignoring key removal request");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary ignoring removeKey");
+    }
 }
 void
 QPDFObjectHandle::replaceOrRemoveKey(std::string const& key,
 				     QPDFObjectHandle value)
 {
-    assertDictionary();
-    return dynamic_cast<QPDF_Dictionary*>(
-	m->obj.getPointer())->replaceOrRemoveKey(key, value);
+    if (isDictionary())
+    {
+        dynamic_cast<QPDF_Dictionary*>(
+            m->obj.getPointer())->replaceOrRemoveKey(key, value);
+    }
+    else
+    {
+        typeWarning("dictionary", "ignoring key removal/replacement request");
+        QTC::TC("qpdf", "QPDFObjectHandle dictionary ignoring removereplace");
+    }
 }
 // Stream accessors
@@ -1173,35 +1408,45 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
     std::vector<parser_state_e> state_stack;
     state_stack.push_back(st_top);
     std::vector<qpdf_offset_t> offset_stack;
-    offset_stack.push_back(input->tell());
+    qpdf_offset_t offset = input->tell();
+    offset_stack.push_back(offset);
     bool done = false;
     while (! done)
     {
         std::vector<QPDFObjectHandle>& olist = olist_stack.back();
         parser_state_e state = state_stack.back();
-        qpdf_offset_t offset = offset_stack.back();
+        offset = offset_stack.back();
 	object = QPDFObjectHandle();
 	QPDFTokenizer::Token token =
-            tokenizer.readToken(input, object_description);
+            tokenizer.readToken(input, object_description, true);
 	switch (token.getType())
 	{
           case QPDFTokenizer::tt_eof:
-            if (content_stream)
+            if (! content_stream)
             {
-                state = st_eof;
-            }
-            else
-            {
-                // When not in content stream mode, EOF is tt_bad and
-                // throws an exception before we get here.
-                throw std::logic_error(
-                    "EOF received while not in content stream mode");
+                QTC::TC("qpdf", "QPDFObjectHandle eof in parseInternal");
+                warn(context,
+                     QPDFExc(qpdf_e_damaged_pdf, input->getName(),
+                             object_description,
+                             input->getLastOffset(),
+                             "unexpected EOF"));
             }
+            state = st_eof;
             break;
+          case QPDFTokenizer::tt_bad:
+	    QTC::TC("qpdf", "QPDFObjectHandle bad token in parse");
+            warn(context,
+                 QPDFExc(qpdf_e_damaged_pdf, input->getName(),
+                         object_description,
+                         input->getLastOffset(),
+                         token.getErrorMessage()));
+            object = newNull();
+	    break;
+
 	  case QPDFTokenizer::tt_brace_open:
 	  case QPDFTokenizer::tt_brace_close:
 	    QTC::TC("qpdf", "QPDFObjectHandle bad brace");
@@ -1375,11 +1620,19 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
                              "parse error while reading object"));
             }
             done = true;
-            // Leave object uninitialized to indicate EOF
+            // In content stream mode, leave object uninitialized to
+            // indicate EOF
+            if (! content_stream)
+            {
+                object = newNull();
+            }
             break;
           case st_dictionary:
           case st_array:
+            setObjectDescriptionFromInput(
+                object, context, object_description, input,
+                input->getLastOffset());
             olist.push_back(object);
             break;
@@ -1402,6 +1655,8 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
             if (old_state == st_array)
             {
                 object = newArray(olist);
+                setObjectDescriptionFromInput(
+                    object, context, object_description, input, offset);
             }
             else if (old_state == st_dictionary)
             {
@@ -1458,6 +1713,8 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
                                  "dictionary ended prematurely; "
                                  "using null as value for last key"));
                         val = newNull();
+                        setObjectDescriptionFromInput(
+                            val, context, object_description, input, offset);
                     }
                     else
                     {
@@ -1466,6 +1723,8 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
                     dict[key_obj.getName()] = val;
                 }
                 object = newDictionary(dict);
+                setObjectDescriptionFromInput(
+                    object, context, object_description, input, offset);
             }
             olist_stack.pop_back();
             offset_stack.pop_back();
@@ -1480,6 +1739,8 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
         }
     }
+    setObjectDescriptionFromInput(
+        object, context, object_description, input, offset);
     return object;
 }
@@ -1635,6 +1896,26 @@ QPDFObjectHandle::newReserved(QPDF* qpdf)
     return result;
 }
+void
+QPDFObjectHandle::setObjectDescription(QPDF* owning_qpdf,
+                                       std::string const& object_description)
+{
+    if (isInitialized() && this->m->obj.getPointer())
+    {
+        this->m->obj->setDescription(owning_qpdf, object_description);
+    }
+}
+
+bool
+QPDFObjectHandle::hasObjectDescription()
+{
+    if (isInitialized() && this->m->obj.getPointer())
+    {
+        return this->m->obj->hasDescription();
+    }
+    return false;
+}
+
 QPDFObjectHandle
 QPDFObjectHandle::shallowCopy()
 {
@@ -1793,85 +2074,127 @@ QPDFObjectHandle::assertInitialized() const
 }
 void
-QPDFObjectHandle::assertType(char const* type_name, bool istype) const
+QPDFObjectHandle::typeWarning(char const* expected_type,
+                              std::string const& warning)
+{
+    QPDF* context = 0;
+    std::string description;
+    if (this->m->obj->getDescription(context, description))
+    {
+        warn(context,
+             QPDFExc(
+                 qpdf_e_damaged_pdf,
+                 "", description, 0,
+                 std::string("operation for ") + expected_type +
+                 " attempted on object of type " +
+                 getTypeName() + ": " + warning));
+    }
+    else
+    {
+        assertType(expected_type, false);
+    }
+}
+
+void
+QPDFObjectHandle::objectWarning(std::string const& warning)
+{
+    QPDF* context = 0;
+    std::string description;
+    if (this->m->obj->getDescription(context, description))
+    {
+        warn(context,
+             QPDFExc(
+                 qpdf_e_damaged_pdf,
+                 "", description, 0,
+                 warning));
+    }
+    else
+    {
+        throw std::logic_error(warning);
+    }
+}
+
+void
+QPDFObjectHandle::assertType(char const* type_name, bool istype)
 {
     if (! istype)
     {
 	throw std::logic_error(std::string("operation for ") + type_name +
-			       " object attempted on object of wrong type");
+			       " attempted on object of type " +
+                               getTypeName());
     }
 }
 void
 QPDFObjectHandle::assertNull()
 {
-    assertType("Null", isNull());
+    assertType("null", isNull());
 }
 void
 QPDFObjectHandle::assertBool()
 {
-    assertType("Boolean", isBool());
+    assertType("boolean", isBool());
 }
 void
 QPDFObjectHandle::assertInteger()
 {
-    assertType("Integer", isInteger());
+    assertType("integer", isInteger());
 }
 void
 QPDFObjectHandle::assertReal()
 {
-    assertType("Real", isReal());
+    assertType("real", isReal());
 }
 void
 QPDFObjectHandle::assertName()
 {
-    assertType("Name", isName());
+    assertType("name", isName());
 }
 void
 QPDFObjectHandle::assertString()
 {
-    assertType("String", isString());
+    assertType("string", isString());
 }
 void
 QPDFObjectHandle::assertOperator()
 {
-    assertType("Operator", isOperator());
+    assertType("operator", isOperator());
 }
 void
 QPDFObjectHandle::assertInlineImage()
 {
-    assertType("InlineImage", isInlineImage());
+    assertType("inlineimage", isInlineImage());
 }
 void
 QPDFObjectHandle::assertArray()
 {
-    assertType("Array", isArray());
+    assertType("array", isArray());
 }
 void
 QPDFObjectHandle::assertDictionary()
 {
-    assertType("Dictionary", isDictionary());
+    assertType("dictionary", isDictionary());
 }
 void
 QPDFObjectHandle::assertStream()
 {
-    assertType("Stream", isStream());
+    assertType("stream", isStream());
 }
 void
 QPDFObjectHandle::assertReserved()
 {
-    assertType("Reserved", isReserved());
+    assertType("reserved", isReserved());
 }
 void
@@ -1887,13 +2210,13 @@ QPDFObjectHandle::assertIndirect()
 void
 QPDFObjectHandle::assertScalar()
 {
-    assertType("Scalar", isScalar());
+    assertType("scalar", isScalar());
 }
 void
 QPDFObjectHandle::assertNumber()
 {
-    assertType("Number", isNumber());
+    assertType("number", isNumber());
 }
 bool
@@ -1928,7 +2251,8 @@ QPDFObjectHandle::dereference()
 	    this->m->qpdf, this->m->objid, this->m->generation);
 	if (obj.getPointer() == 0)
 	{
-	    QTC::TC("qpdf", "QPDFObjectHandle indirect to unknown");
+            // QPDF::resolve never returns an uninitialized object, but
+            // check just in case.
 	    this->m->obj = new QPDF_Null();
 	}
         else if (dynamic_cast<QPDF_Reserved*>(obj.getPointer()))
@@ -640,7 +640,9 @@ QPDFTokenizer::readToken(PointerHolder&lt;InputSource&gt; input,
                 presented_eof = true;
                 if ((this->m->type == tt_eof) && (! this->m->allow_eof))
                 {
-                    QTC::TC("qpdf", "QPDFTokenizer EOF when not allowed");
+                    // Nothing in the qpdf library calls readToken
+                    // without allowEOF anymore, so this case is not
+                    // exercised.
                     this->m->type = tt_bad;
                     this->m->error_message = "unexpected EOF";
                     offset = input->getLastOffset();
@@ -677,7 +679,10 @@ QPDFTokenizer::readToken(PointerHolder&lt;InputSource&gt; input,
 	input->unreadCh(char_to_unread);
     }
-    input->setLastOffset(offset);
+    if (token.getType() != tt_eof)
+    {
+        input->setLastOffset(offset);
+    }
     if (token.getType() == tt_bad)
     {
 #include <qpdf/QPDF_Array.hh>
+#include <qpdf/QUtil.hh>
 #include <stdexcept>
 QPDF_Array::QPDF_Array(std::vector<QPDFObjectHandle> const& items) :
@@ -46,6 +47,12 @@ QPDF_Array::getTypeName() const
     return "array";
 }
+void
+QPDF_Array::setDescription(QPDF* qpdf, std::string const& description)
+{
+    this->QPDFObject::setDescription(qpdf, description);
+}
+
 int
 QPDF_Array::getNItems() const
 {
@@ -51,6 +51,12 @@ QPDF_Dictionary::getTypeName() const
     return "dictionary";
 }
+void
+QPDF_Dictionary::setDescription(QPDF* qpdf, std::string const& description)
+{
+    this->QPDFObject::setDescription(qpdf, description);
+}
+
 bool
 QPDF_Dictionary::hasKey(std::string const& key)
 {
@@ -70,7 +76,15 @@ QPDF_Dictionary::getKey(std::string const&amp; key)
     }
     else
     {
-	return QPDFObjectHandle::newNull();
+        QPDFObjectHandle null = QPDFObjectHandle::newNull();
+        QPDF* qpdf = 0;
+        std::string description;
+        if (getDescription(qpdf, description))
+        {
+            null.setObjectDescription(
+                qpdf, description + " -> dictionary key " + key);
+        }
+	return null;
     }
 }
@@ -93,13 +107,12 @@ QPDF_Dictionary::getKeys()
 std::map<std::string, QPDFObjectHandle> const&
 QPDF_Dictionary::getAsMap() const
 {
-
     return this->items;
 }
 void
 QPDF_Dictionary::replaceKey(std::string const& key,
-			    QPDFObjectHandle const& value)
+			    QPDFObjectHandle value)
 {
     // add or replace value
     this->items[key] = value;
@@ -39,6 +39,7 @@ QPDF_Stream::QPDF_Stream(QPDF* qpdf, int objid, int generation,
 	    "stream object instantiated with non-dictionary "
 	    "object for dictionary");
     }
+    setStreamDescription();
 }
 QPDF_Stream::~QPDF_Stream()
@@ -85,6 +86,35 @@ QPDF_Stream::getTypeName() const
     return "stream";
 }
+void
+QPDF_Stream::setDescription(QPDF* qpdf, std::string const& description)
+{
+    this->QPDFObject::setDescription(qpdf, description);
+    setDictDescription();
+}
+
+void
+QPDF_Stream::setStreamDescription()
+{
+    setDescription(
+        this->qpdf,
+        "stream object " + QUtil::int_to_string(this->objid) + " " +
+        QUtil::int_to_string(this->generation));
+}
+
+void
+QPDF_Stream::setDictDescription()
+{
+    QPDF* qpdf = 0;
+    std::string description;
+    if ((! this->stream_dict.hasObjectDescription()) &&
+        getDescription(qpdf, description))
+    {
+        this->stream_dict.setObjectDescription(
+            qpdf, description + " -> stream dictionary");
+    }
+}
+
 QPDFObjectHandle
 QPDF_Stream::getDict() const
 {
@@ -688,6 +718,7 @@ void
 QPDF_Stream::replaceDict(QPDFObjectHandle new_dict)
 {
     this->stream_dict = new_dict;
+    setDictDescription();
     QPDFObjectHandle length_obj = new_dict.getKey("/Length");
     if (length_obj.isInteger())
     {
@@ -121,10 +121,10 @@ QPDF::isLinearized()
             ++p;
         }
-        QPDFTokenizer::Token t1 = readToken(this->m->file, true);
-        QPDFTokenizer::Token t2 = readToken(this->m->file, true);
-        QPDFTokenizer::Token t3 = readToken(this->m->file, true);
-        QPDFTokenizer::Token t4 = readToken(this->m->file, true);
+        QPDFTokenizer::Token t1 = readToken(this->m->file);
+        QPDFTokenizer::Token t2 = readToken(this->m->file);
+        QPDFTokenizer::Token t3 = readToken(this->m->file);
+        QPDFTokenizer::Token t4 = readToken(this->m->file);
         if ((t1.getType() == QPDFTokenizer::tt_integer) &&
             (t2.getType() == QPDFTokenizer::tt_integer) &&
             (t3 == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "obj")) &&
@@ -14,6 +14,7 @@ class QPDF_Array: public QPDFObject
     virtual std::string unparse();
     virtual QPDFObject::object_type_e getTypeCode() const;
     virtual char const* getTypeName() const;
+    virtual void setDescription(QPDF*, std::string const&);
     int getNItems() const;
     QPDFObjectHandle getItem(int n) const;
@@ -16,6 +16,7 @@ class QPDF_Dictionary: public QPDFObject
     virtual std::string unparse();
     virtual QPDFObject::object_type_e getTypeCode() const;
     virtual char const* getTypeName() const;
+    virtual void setDescription(QPDF*, std::string const&);
     // hasKey() and getKeys() treat keys with null values as if they
     // aren't there.  getKey() returns null for the value of a
@@ -26,7 +27,7 @@ class QPDF_Dictionary: public QPDFObject
     std::map<std::string, QPDFObjectHandle> const& getAsMap() const;
     // Replace value of key, adding it if it does not exist
-    void replaceKey(std::string const& key, QPDFObjectHandle const&);
+    void replaceKey(std::string const& key, QPDFObjectHandle);
     // Remove key, doing nothing if key does not exist
     void removeKey(std::string const& key);
     // If object is null, replace key; otherwise, remove key
@@ -19,6 +19,7 @@ class QPDF_Stream: public QPDFObject
     virtual std::string unparse();
     virtual QPDFObject::object_type_e getTypeCode() const;
     virtual char const* getTypeName() const;
+    virtual void setDescription(QPDF*, std::string const&);
     QPDFObjectHandle getDict() const;
     bool isDataModified() const;
@@ -66,6 +67,8 @@ class QPDF_Stream: public QPDFObject
                     int& colors, int& bits_per_component,
                     bool& early_code_change);
     void warn(QPDFExc const& e);
+    void setDictDescription();
+    void setStreamDescription();
     QPDF* qpdf;
     int objid;
@@ -105,7 +105,6 @@ QPDF reconstructed xref table 0
 QPDF recovered in readObjectAtOffset 0
 QPDF recovered stream length 0
 QPDF found wrong endstream in recovery 0
-QPDFObjectHandle indirect to unknown 0
 QPDF_Stream pipeStreamData with null pipeline 0
 QPDFWriter not recompressing /FlateDecode 0
 QPDF_encryption xref stream from encrypted file 0
@@ -300,10 +299,37 @@ qpdf-c called qpdf_set_compress_streams 0
 qpdf-c called qpdf_set_preserve_unreferenced_objects 0
 qpdf-c called qpdf_set_newline_before_endstream 0
 QPDF_Stream TIFF predictor 0
-QPDFTokenizer EOF when not allowed 0
 QPDFTokenizer inline image at EOF 0
 Pl_QPDFTokenizer found ID 0
 QPDFObjectHandle non-stream in stream array 0
 QPDFObjectHandle coalesce called on stream 0
 QPDFObjectHandle coalesce provide stream data 0
 QPDF_Stream bad token at end during normalize 0
+QPDFObjectHandle bad token in parse 0
+QPDFObjectHandle eof in parseInternal 0
+QPDFObjectHandle array bounds 0
+QPDFObjectHandle boolean returning false 0
+QPDFObjectHandle integer returning 0 0
+QPDFObjectHandle real returning 0.0 0
+QPDFObjectHandle name returning dummy name 0
+QPDFObjectHandle string returning empty string 0
+QPDFObjectHandle string returning empty utf8 0
+QPDFObjectHandle operator returning fake value 0
+QPDFObjectHandle inlineimage returning empty data 0
+QPDFObjectHandle array treating as empty 0
+QPDFObjectHandle array null for non-array 0
+QPDFObjectHandle array treating as empty vector 0
+QPDFObjectHandle array ignoring set item 0
+QPDFObjectHandle array ignoring replace items 0
+QPDFObjectHandle array ignoring insert item 0
+QPDFObjectHandle array ignoring append item 0
+QPDFObjectHandle array ignoring erase item 0
+QPDFObjectHandle dictionary false for hasKey 0
+QPDFObjectHandle dictionary null for getKey 0
+QPDFObjectHandle dictionary empty set for getKeys 0
+QPDFObjectHandle dictionary empty map for asMap 0
+QPDFObjectHandle dictionary ignoring replaceKey 0
+QPDFObjectHandle dictionary ignoring removeKey 0
+QPDFObjectHandle dictionary ignoring removereplace 0
+QPDFObjectHandle numeric non-numeric 0
+QPDFObjectHandle erase array bounds 0
@@ -212,7 +212,7 @@ my @bug_tests = (
     ["99", "object 0", 2],
     ["99b", "object 0", 2],
     ["100", "xref reconstruction loop", 2],
-    ["101", "resolve for exception text", 2],
+    ["101", "resolve for exception text", 3],
     ["117", "other infinite loop", 2],
     ["118", "other infinite loop", 2],
     ["119", "other infinite loop", 3],
@@ -736,6 +736,33 @@ $td-&gt;runtest(&quot;stream with tiff predictor&quot;,
 show_ntests();
 # ----------
+$td->notify("--- Type checks ---");
+$n_tests += 4;
+# Whenever object-types.pdf is edited, object-types-os.pdf should be
+# regenerated.
+$td->runtest("ensure object-types-os is up-to-date",
+             {$td->COMMAND =>
+                  "qpdf" .
+                  " --object-streams=generate" .
+                  " --deterministic-id" .
+                  " --stream-data=uncompress" .
+                  " object-types.pdf a.pdf"},
+             {$td->STRING => "", $td->EXIT_STATUS => 0});
+$td->runtest("check file",
+             {$td->FILE => "a.pdf"},
+             {$td->FILE => "object-types-os.pdf"});
+$td->runtest("type checks",
+             {$td->COMMAND => "test_driver 42 object-types.pdf"},
+             {$td->FILE => "object-types.out",
+              $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+$td->runtest("type checks with object streams",
+             {$td->COMMAND => "test_driver 42 object-types-os.pdf"},
+             {$td->FILE => "object-types-os.out",
+              $td->EXIT_STATUS => 0},
+             $td->NORMALIZE_NEWLINES);
+
+# ----------
 $td->notify("--- Coalesce contents ---");
 $n_tests += 6;
@@ -1200,7 +1227,7 @@ $n_tests += @badfiles + 3;
 # have error conditions that used to be fatal but are now considered
 # non-fatal.
 my %badtest_overrides = ();
-for(6, 12..15, 17, 22..28, 30..32, 34, 36)
+for(6, 12..15, 17, 18..32, 34, 36)
 {
     $badtest_overrides{$_} = 0;
 }
@@ -1243,7 +1270,7 @@ $n_tests += @badfiles + 6;
 # though in some cases it may.  Acrobat Reader would not be able to
 # recover any of these files any better.
 my %recover_failures = ();
-for (1, 7, 16, 18..21, 29, 35)
+for (1, 7, 16, 35)
 {
     $recover_failures{$_} = 1;
 }
 WARNING: bad16.pdf (trailer, offset 753): unexpected dictionary close token
 WARNING: bad16.pdf (trailer, offset 756): unexpected dictionary close token
 WARNING: bad16.pdf (trailer, offset 759): unknown token while reading object; treating as string
-WARNING: bad16.pdf: file is damaged
 WARNING: bad16.pdf (trailer, offset 779): unexpected EOF
+WARNING: bad16.pdf (trailer, offset 779): parse error while reading object
+WARNING: bad16.pdf: file is damaged
+WARNING: bad16.pdf (offset 712): expected trailer dictionary
 WARNING: bad16.pdf: Attempting to reconstruct cross-reference table
 WARNING: bad16.pdf (trailer, offset 753): unexpected dictionary close token
 WARNING: bad16.pdf (trailer, offset 756): unexpected dictionary close token
 WARNING: bad16.pdf (trailer, offset 759): unknown token while reading object; treating as string
-bad16.pdf (trailer, offset 779): unexpected EOF
+WARNING: bad16.pdf (trailer, offset 779): unexpected EOF
+WARNING: bad16.pdf (trailer, offset 779): parse error while reading object
+bad16.pdf: unable to find trailer dictionary while recovering damaged file
 WARNING: bad16.pdf (trailer, offset 753): unexpected dictionary close token
 WARNING: bad16.pdf (trailer, offset 756): unexpected dictionary close token
 WARNING: bad16.pdf (trailer, offset 759): unknown token while reading object; treating as string
-bad16.pdf (trailer, offset 779): unexpected EOF
+WARNING: bad16.pdf (trailer, offset 779): unexpected EOF
+WARNING: bad16.pdf (trailer, offset 779): parse error while reading object
+bad16.pdf (offset 712): expected trailer dictionary
-WARNING: bad18.pdf: file is damaged
 WARNING: bad18.pdf (trailer, offset 753): unexpected )
-WARNING: bad18.pdf: Attempting to reconstruct cross-reference table
-bad18.pdf (trailer, offset 753): unexpected )
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 1 done
-bad18.pdf (trailer, offset 753): unexpected )
+WARNING: bad18.pdf (trailer, offset 753): unexpected )
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 0 done
-WARNING: bad19.pdf: file is damaged
 WARNING: bad19.pdf (trailer, offset 753): unexpected >
-WARNING: bad19.pdf: Attempting to reconstruct cross-reference table
-bad19.pdf (trailer, offset 753): unexpected >
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 1 done
-bad19.pdf (trailer, offset 753): unexpected >
+WARNING: bad19.pdf (trailer, offset 753): unexpected >
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 0 done
-WARNING: bad20.pdf: file is damaged
 WARNING: bad20.pdf (trailer, offset 753): invalid character (q) in hexstring
-WARNING: bad20.pdf: Attempting to reconstruct cross-reference table
-bad20.pdf (trailer, offset 753): invalid character (q) in hexstring
+WARNING: bad20.pdf (trailer, offset 757): unknown token while reading object; treating as string
+WARNING: bad20.pdf (trailer, offset 758): unexpected >
+WARNING: bad20.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: bad20.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake2
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 1 done
-bad20.pdf (trailer, offset 753): invalid character (q) in hexstring
+WARNING: bad20.pdf (trailer, offset 753): invalid character (q) in hexstring
+WARNING: bad20.pdf (trailer, offset 757): unknown token while reading object; treating as string
+WARNING: bad20.pdf (trailer, offset 758): unexpected >
+WARNING: bad20.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: bad20.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake2
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 0 done
-WARNING: bad21.pdf: file is damaged
 WARNING: bad21.pdf (trailer, offset 742): invalid name token
-WARNING: bad21.pdf: Attempting to reconstruct cross-reference table
-bad21.pdf (trailer, offset 742): invalid name token
+WARNING: bad21.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: bad21.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake2
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 1 done
-bad21.pdf (trailer, offset 742): invalid name token
+WARNING: bad21.pdf (trailer, offset 742): invalid name token
+WARNING: bad21.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: bad21.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake2
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 0 done
-WARNING: bad29.pdf: file is damaged
 WARNING: bad29.pdf (trailer, offset 742): null character not allowed in name token
-WARNING: bad29.pdf: Attempting to reconstruct cross-reference table
-bad29.pdf (trailer, offset 742): null character not allowed in name token
+WARNING: bad29.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: bad29.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake2
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 1 done
-bad29.pdf (trailer, offset 742): null character not allowed in name token
+WARNING: bad29.pdf (trailer, offset 742): null character not allowed in name token
+WARNING: bad29.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: bad29.pdf (trailer, offset 715): expected dictionary key but found non-name object; inserting key /QPDFFake2
+/QTest is implicit
+/QTest is direct and has type null (2)
+/QTest is null
+unparse: null
+unparseResolved: null
+test 0 done
@@ -8,6 +8,9 @@ WARNING: issue-100.pdf (object 5 0, offset 294): unknown token while reading obj
 WARNING: issue-100.pdf (object 5 0, offset 297): unknown token while reading object; treating as string
 WARNING: issue-100.pdf (object 5 0, offset 304): unknown token while reading object; treating as string
 WARNING: issue-100.pdf (object 5 0, offset 308): unexpected )
+WARNING: issue-100.pdf (object 5 0, offset 316): treating unexpected array close token as null
+WARNING: issue-100.pdf (object 5 0, offset 227): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: issue-100.pdf (object 5 0, offset 321): expected endobj
 WARNING: issue-100.pdf (object 5 0, offset 418): /Length key in stream dictionary is not an integer
 WARNING: issue-100.pdf (object 5 0, offset 489): attempting to recover stream length
 WARNING: issue-100.pdf (object 5 0, offset 489): recovered stream length: 12
@@ -56,4 +56,72 @@ WARNING: issue-101.pdf (object 11 0, offset 811): unknown token while reading ob
 WARNING: issue-101.pdf (object 11 0, offset 819): unknown token while reading object; treating as string
 WARNING: issue-101.pdf (object 11 0, offset 832): unknown token while reading object; treating as string
 WARNING: issue-101.pdf (object 11 0, offset 856): unexpected >
-issue-101.pdf (offset 856): unable to find /Root dictionary
+WARNING: issue-101.pdf (object 11 0, offset 857): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 868): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 887): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 897): unexpected )
+WARNING: issue-101.pdf (object 11 0, offset 898): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 909): invalid character (¤) in hexstring
+WARNING: issue-101.pdf (object 11 0, offset 911): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 929): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 930): invalid character (²) in hexstring
+WARNING: issue-101.pdf (object 11 0, offset 932): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 944): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 947): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 970): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1046): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1067): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1075): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1080): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1084): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1102): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1112): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1124): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1133): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1145): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1148): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1150): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1151): unexpected )
+WARNING: issue-101.pdf (object 11 0, offset 1153): unexpected dictionary close token
+WARNING: issue-101.pdf (object 11 0, offset 1156): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1163): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1168): unexpected >
+WARNING: issue-101.pdf (object 11 0, offset 1170): invalid character (I) in hexstring
+WARNING: issue-101.pdf (object 11 0, offset 1167): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: issue-101.pdf (object 11 0, offset 1167): expected dictionary key but found non-name object; inserting key /QPDFFake2
+WARNING: issue-101.pdf (object 11 0, offset 1167): expected dictionary key but found non-name object; inserting key /QPDFFake3
+WARNING: issue-101.pdf (object 11 0, offset 1176): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1180): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1184): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1190): unexpected >
+WARNING: issue-101.pdf (object 11 0, offset 1192): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1195): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1205): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1217): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1224): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1236): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1242): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: issue-101.pdf (object 11 0, offset 1242): dictionary ended prematurely; using null as value for last key
+WARNING: issue-101.pdf (object 11 0, offset 1275): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1287): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1291): unexpected dictionary close token
+WARNING: issue-101.pdf (object 11 0, offset 1294): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1306): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1322): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1325): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1329): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1341): treating unexpected array close token as null
+WARNING: issue-101.pdf (object 11 0, offset 1312): expected dictionary key but found non-name object; inserting key /QPDFFake1
+WARNING: issue-101.pdf (object 11 0, offset 1312): expected dictionary key but found non-name object; inserting key /QPDFFake2
+WARNING: issue-101.pdf (object 11 0, offset 1312): expected dictionary key but found non-name object; inserting key /QPDFFake3
+WARNING: issue-101.pdf (object 11 0, offset 1312): expected dictionary key but found non-name object; inserting key /QPDFFake4
+WARNING: issue-101.pdf (object 11 0, offset 1312): dictionary ended prematurely; using null as value for last key
+WARNING: issue-101.pdf (object 11 0, offset 1349): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1353): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1357): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1359): unknown token while reading object; treating as string
+WARNING: issue-101.pdf (object 11 0, offset 1368): unexpected )
+WARNING: issue-101.pdf (object 11 0, offset 1373): expected endobj
+WARNING: issue-101.pdf (object 8 0, offset 4067): invalid character ()) in hexstring
+WARNING: issue-101.pdf (object 8 0, offset 4069): expected endobj
+qpdf: operation succeeded with warnings; resulting file may have some problems
@@ -2,4 +2,6 @@ WARNING: issue-146.pdf: file is damaged
 WARNING: issue-146.pdf: can't find startxref
 WARNING: issue-146.pdf: Attempting to reconstruct cross-reference table
 WARNING: issue-146.pdf (trailer, offset 20728): unknown token while reading object; treating as string
-issue-146.pdf (trailer, offset 20732): unexpected EOF
+WARNING: issue-146.pdf (trailer, offset 20732): unexpected EOF
+WARNING: issue-146.pdf (trailer, offset 20732): parse error while reading object
+issue-146.pdf: unable to find trailer dictionary while recovering damaged file
@@ -6,5 +6,6 @@ WARNING: issue-51.pdf (offset 70): loop detected resolving object 2 0
 WARNING: issue-51.pdf (object 2 0, offset 26): /Length key in stream dictionary is not an integer
 WARNING: issue-51.pdf (object 2 0, offset 71): attempting to recover stream length
 WARNING: issue-51.pdf (object 2 0, offset 71): unable to recover stream data; treating stream as empty
-WARNING: issue-51.pdf (object 2 0, offset 977): unexpected EOF
+WARNING: issue-51.pdf (object 2 0, offset 977): expected endobj
+WARNING: issue-51.pdf (object 2 0, offset 977): EOF after endobj
 qpdf: operation succeeded with warnings; resulting file may have some problems
@@ -2,7 +2,7 @@ checking linearization-bounds-1.pdf
 PDF Version: 1.3
 File is not encrypted
 File is linearized
-WARNING: linearization-bounds-1.pdf (linearization hint stream: object 62 0, offset 12302): unexpected EOF
+WARNING: linearization-bounds-1.pdf (linearization hint stream: object 62 0, offset 12302): expected endstream
 WARNING: linearization-bounds-1.pdf (linearization hint stream: object 62 0, offset 1183): attempting to recover stream length
 WARNING: linearization-bounds-1.pdf (linearization hint stream: object 62 0, offset 1183): recovered stream length: 106
 linearization-bounds-1.pdf (linearization hint table, offset 1183): /S (shared object) offset is out of bounds
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 347: operation for string attempted on object of type dictionary: returning empty string
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 384: returning null for out of bounds array access
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 384: returning null for out of bounds array access
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: returning null
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: ignoring attempt to append item
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 384: ignoring attempt to erase out of bounds array item
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 384: ignoring attempt to erase out of bounds array item
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: ignoring attempt to erase item
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: ignoring attempt to insert item
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: ignoring attempt to replace items
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: ignoring attempt to set item
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: treating as empty
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for array attempted on object of type integer: treating as empty
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for boolean attempted on object of type integer: returning false
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: treating as empty
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: treating as empty
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: returning false for a key containment request
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: ignoring key removal request
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: ignoring key removal/replacement request
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: ignoring key removal/replacement request
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: ignoring key replacement request
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for dictionary attempted on object of type integer: returning null for attempted key retrieval
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for inlineimage attempted on object of type integer: returning empty data
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 362: operation for integer attempted on object of type dictionary: returning 0
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for name attempted on object of type integer: returning dummy name
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for operator attempted on object of type integer: returning fake value
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 362: operation for real attempted on object of type dictionary: returning 0.0
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for string attempted on object of type integer: returning empty string
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 429: operation for string attempted on object of type integer: returning empty string
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 362: operation for number attempted on object of type dictionary: returning 0
+One error
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 385: operation for string attempted on object of type name: returning empty string
+One error
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 362 -> dictionary key /Quack: operation for string attempted on object of type null: returning empty string
+Two errors
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 384: returning null for out of bounds array access
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 384 -> null returned from invalid array access: operation for string attempted on object of type null: returning empty string
+One error
+WARNING: object-types-os.pdf object stream 1, object 7 0 at offset 400: operation for string attempted on object of type name: returning empty string
+WARNING: object-types-os.pdf, object 8 0 at offset 538 -> dictionary key /Potato: operation for name attempted on object of type null: returning dummy name
+test 42 done
+WARNING: object-types.pdf, object 8 0 at offset 657: operation for string attempted on object of type dictionary: returning empty string
+WARNING: object-types.pdf, object 8 0 at offset 717: returning null for out of bounds array access
+WARNING: object-types.pdf, object 8 0 at offset 717: returning null for out of bounds array access
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: returning null
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: ignoring attempt to append item
+WARNING: object-types.pdf, object 8 0 at offset 717: ignoring attempt to erase out of bounds array item
+WARNING: object-types.pdf, object 8 0 at offset 717: ignoring attempt to erase out of bounds array item
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: ignoring attempt to erase item
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: ignoring attempt to insert item
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: ignoring attempt to replace items
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: ignoring attempt to set item
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: treating as empty
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for array attempted on object of type integer: treating as empty
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for boolean attempted on object of type integer: returning false
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: treating as empty
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: treating as empty
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: returning false for a key containment request
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: ignoring key removal request
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: ignoring key removal/replacement request
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: ignoring key removal/replacement request
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: ignoring key replacement request
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for dictionary attempted on object of type integer: returning null for attempted key retrieval
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for inlineimage attempted on object of type integer: returning empty data
+WARNING: object-types.pdf, object 8 0 at offset 687: operation for integer attempted on object of type dictionary: returning 0
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for name attempted on object of type integer: returning dummy name
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for operator attempted on object of type integer: returning fake value
+WARNING: object-types.pdf, object 8 0 at offset 687: operation for real attempted on object of type dictionary: returning 0.0
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for string attempted on object of type integer: returning empty string
+WARNING: object-types.pdf, object 8 0 at offset 669: operation for string attempted on object of type integer: returning empty string
+WARNING: object-types.pdf, object 8 0 at offset 687: operation for number attempted on object of type dictionary: returning 0
+One error
+WARNING: object-types.pdf, object 8 0 at offset 724: operation for string attempted on object of type name: returning empty string
+One error
+WARNING: object-types.pdf, object 8 0 at offset 687 -> dictionary key /Quack: operation for string attempted on object of type null: returning empty string
+Two errors
+WARNING: object-types.pdf, object 8 0 at offset 717: returning null for out of bounds array access
+WARNING: object-types.pdf, object 8 0 at offset 717 -> null returned from invalid array access: operation for string attempted on object of type null: returning empty string
+One error
+WARNING: object-types.pdf, object 8 0 at offset 745: operation for string attempted on object of type name: returning empty string
+WARNING: object-types.pdf, object 4 0 at offset 386 -> dictionary key /Potato: operation for name attempted on object of type null: returning dummy name
+test 42 done
+%PDF-1.3
+%¿÷¢þ
+%QDF-1.0
+
+1 0 obj
+<<
+  /Pages 2 0 R
+  /Type /Catalog
+>>
+endobj
+
+2 0 obj
+<<
+  /Count 1
+  /Kids [
+    3 0 R
+  ]
+  /Type /Pages
+>>
+endobj
+
+%% Page 1
+3 0 obj
+<<
+  /Contents 4 0 R
+  /MediaBox [
+    0
+    0
+    612
+    792
+  ]
+  /Parent 2 0 R
+  /Resources <<
+    /Font <<
+      /F1 6 0 R
+    >>
+    /ProcSet 7 0 R
+  >>
+  /Type /Page
+>>
+endobj
+
+%% Contents for page 1
+4 0 obj
+<<
+  /Length 5 0 R
+>>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+
+5 0 obj
+44
+endobj
+
+6 0 obj
+<<
+  /BaseFont /Helvetica
+  /Encoding /WinAnsiEncoding
+  /Name /F1
+  /Subtype /Type1
+  /Type /Font
+>>
+endobj
+
+7 0 obj
+[
+  /PDF
+  /Text
+]
+endobj
+
+8 0 obj
+<<
+  /Integer 5
+  /Dictionary <<
+    /Key1 /Value1
+    /Key2 [
+      /Item0
+      << /K [ /V ] >>
+      /Item2
+    ]
+  >>
+>>
+endobj
+
+xref
+0 9
+0000000000 65535 f 
+0000000025 00000 n 
+0000000079 00000 n 
+0000000161 00000 n 
+0000000376 00000 n 
+0000000475 00000 n 
+0000000494 00000 n 
+0000000612 00000 n 
+0000000647 00000 n 
+trailer <<
+  /Root 1 0 R
+  /Size 9
+  /ID [<5ecb4bcc69402d31e10c2e63ec8500ee><5ecb4bcc69402d31e10c2e63ec8500ee>]
+  /QTest 8 0 R
+>>
+startxref
+788
+%%EOF
@@ -1390,6 +1390,66 @@ void runtest(int n, char const* filename1, char const* arg2)
         w.setStaticID(true);
         w.write();
     }
+    else if (n == 42)
+    {
+        // Access objects as wrong type. This test case is crafted to
+        // work with object-types.pdf.
+        QPDFObjectHandle qtest = pdf.getTrailer().getKey("/QTest");
+        QPDFObjectHandle array = qtest.getKey("/Dictionary").getKey("/Key2");
+        QPDFObjectHandle dictionary = qtest.getKey("/Dictionary");
+        QPDFObjectHandle integer = qtest.getKey("/Integer");
+        QPDFObjectHandle null = QPDFObjectHandle::newNull();
+        assert(array.isArray());
+        assert(dictionary.isDictionary());
+        assert("" == qtest.getStringValue());
+        array.getArrayItem(-1).assertNull();
+        array.getArrayItem(16059).assertNull();
+        integer.getArrayItem(0).assertNull();
+        integer.appendItem(null);
+        array.eraseItem(-1);
+        array.eraseItem(16059);
+        integer.eraseItem(0);
+        integer.insertItem(0, null);
+        integer.setArrayFromVector(std::vector<QPDFObjectHandle>());
+        integer.setArrayItem(0, null);
+        assert(0 == integer.getArrayNItems());
+        assert(integer.getArrayAsVector().empty());
+        assert(false == integer.getBoolValue());
+        assert(integer.getDictAsMap().empty());
+        assert(integer.getKeys().empty());
+        assert(false == integer.hasKey("/Potato"));
+        integer.removeKey("/Potato");
+        integer.replaceOrRemoveKey("/Potato", null);
+        integer.replaceOrRemoveKey("/Potato", QPDFObjectHandle::newInteger(1));
+        integer.replaceKey("/Potato", QPDFObjectHandle::newInteger(1));
+        qtest.getKey("/Integer").getKey("/Potato");
+        assert(integer.getInlineImageValue().empty());
+        assert(0 == dictionary.getIntValue());
+        assert("/QPDFFakeName" == integer.getName());
+        assert("QPDFFAKE" == integer.getOperatorValue());
+        assert("0.0" == dictionary.getRealValue());
+        assert(integer.getStringValue().empty());
+        assert(integer.getUTF8Value().empty());
+        assert(0.0 == dictionary.getNumericValue());
+        // Make sure error messages are okay for nested values
+        std::cerr << "One error\n";
+        assert(array.getArrayItem(0).getStringValue().empty());
+        std::cerr << "One error\n";
+        assert(dictionary.getKey("/Quack").getStringValue().empty());
+        assert(array.getArrayItem(1).isDictionary());
+        assert(array.getArrayItem(1).getKey("/K").isArray());
+        assert(array.getArrayItem(1).getKey("/K").getArrayItem(0).isName());
+        assert("/V" ==
+               array.getArrayItem(1).getKey("/K").getArrayItem(0).getName());
+        std::cerr << "Two errors\n";
+        assert(array.getArrayItem(16059).getStringValue().empty());
+        std::cerr << "One error\n";
+        array.getArrayItem(1).getKey("/K").getArrayItem(0).getStringValue();
+        // Stream dictionary
+        QPDFObjectHandle page = pdf.getAllPages()[0];
+        assert("/QPDFFakeName" ==
+               page.getKey("/Contents").getDict().getKey("/Potato").getName());
+    }
     else
     {
 	throw std::runtime_error(std::string("invalid test ") +