OpenSystemsDevelopment / qpdf

Tighten checks for invalid indirect references  during xref reconstru…

Handle default-constructed JSON objects

Tighten checks for invalid indirect references in QPDFParser

Update .clang-format to require braces after control statements

Fix incorrect handling of invalid negative object ids

Fix two errors introduced in #1110 and #1112. Since
#1110, encountering the invalid indirect reference #1110
-2147483648 n R produces an integer underflow which, if
 undetected, immediately trigger a logic error. Since
 #1112, object -1 0 R may be incorrectly identified as
 an earlier generation of itself and deleted,
 invalidating a live iterator.

Use std::vector instead of list and move shared pointers

This is just QPDFJob wiring.

...since they have to be handled before other options. It was working
because, in both cases, `file` was alphabetically before the other
keys, but this implementation gives a stronger guarantee.

Accept --file and --range as named parameters in additional to
allowing positional arguments. This is in preparation for adding
additional flags.

The check for the number of items was in the wrong place.

Tune handling of sparse arrays in QPDF_Array

Sparse arrays are rare. Dynamically create the variables needed to manage
them only when needed.

Tweaks to QPDF::read_xref, removeObject and getCompressibleObjGens