Improve handling of replacing stream data with empty strings

When an empty string was passed to replaceStreamData, the code was passing a null pointer to memcpy. Since a 0 size was also passed, this was harmless, but it triggers sanitizer errors. The code properly handles a null pointer as the buffer in other places.

Improve handling of replacing stream data with empty strings
When an empty string was passed to replaceStreamData, the code was passing a null pointer to memcpy. Since a 0 size was also passed, this was harmless, but it triggers sanitizer errors. The code properly handles a null pointer as the buffer in other places.
Jay Berkenbilt
1 parent 60ec94a7
Showing 1 changed file with 3 additions and 1 deletions
libqpdf/QPDFObjectHandle.cc
@@ -1468,7 +1468,9 @@ QPDFObjectHandle::replaceStreamData(
     assertStream();
     auto b = std::make_shared<Buffer>(data.length());
     unsigned char* bp = b->getBuffer();
-    memcpy(bp, data.c_str(), data.length());
+    if (bp) {
+        memcpy(bp, data.c_str(), data.length());
+    }
     dynamic_cast<QPDF_Stream*>(obj.get())->replaceStreamData(
         b, filter, decode_parms);
 }