POSIX strndup() does not read memory beyond NUL byte of the source
string. Preserve this behavior in libexpat implementation to prevent
access violations and keep portability.
m_eventPtr is a key provider to these functions:
- XML_GetCurrentByteCount
- XML_GetCurrentByteIndex
- XML_GetCurrentColumnNumber
- XML_GetCurrentLineNumber
- XML_GetInputContext
The fix for recursive entity processing introduced a reenter flag that
returns the execution from the current function and switches to entity
processing.
The same fix also updates the m_eventPtr during this switch. However
this update changes the behaviour in certain cases as the older version
does not update the m_eventPtr while recursing into entity processing.
This commit removes the pointer update and restores the old behaviour.
The symptom was:
> [variadic:typing] lib/xmlparse.c:8242: Warning:
> Incorrect type for argument 7. The argument will be cast from unsigned int to int.
When compiling with Emscripten 3.1.6, the symptom was:
> [..]
> /usr/bin/emcc @CMakeFiles/expat.dir/includes_C.rsp -fno-strict-aliasing -fvisibility=hidden -std=c99 -MD -MT CMakeFiles/expat.dir/lib/xmlparse.c.o -MF CMakeFiles/expat.dir/lib/xmlparse.c.o.d -o CMakeFiles/expat.dir/lib/xmlparse.c.o -c /libexpat/expat/lib/xmlparse.c
> /libexpat/expat/lib/xmlparse.c:8132:11: warning: format specifies type 'int' but the argument has type 'ptrdiff_t' (aka 'long') [-Wformat]
> bytesMore, (account == XML_ACCOUNT_DIRECT) ? "DIR" : "EXP",
> ^~~~~~~~~
> 1 warning generated.
> [..]
> /usr/bin/emcc -DXML_TESTING @CMakeFiles/runtests.dir/includes_C.rsp -fno-strict-aliasing -fvisibility=hidden -std=c99 -MD -MT CMakeFiles/runtests.dir/tests/acc_tests.c.o -MF CMakeFiles/runtests.dir/tests/acc_tests.c.o.d -o CMakeFiles/runtests.dir/tests/acc_tests.c.o -c /libexpat/expat/tests/acc_tests.c
> /libexpat/expat/tests/acc_tests.c:279:11: warning: format specifies type 'unsigned int' but the argument has type 'unsigned long' [-Wformat]
> u + 1, countCases, expectedCountBytesDirect, actualCountBytesDirect);
> ^~~~~
> /libexpat/expat/tests/acc_tests.c:279:18: warning: format specifies type 'unsigned int' but the argument has type 'size_t' (aka 'unsigned long') [-Wformat]
> u + 1, countCases, expectedCountBytesDirect, actualCountBytesDirect);
> ^~~~~~~~~~
> /libexpat/expat/tests/acc_tests.c:288:11: warning: format specifies type 'unsigned int' but the argument has type 'unsigned long' [-Wformat]
> u + 1, countCases, expectedCountBytesIndirect,
> ^~~~~
> /libexpat/expat/tests/acc_tests.c:288:18: warning: format specifies type 'unsigned int' but the argument has type 'size_t' (aka 'unsigned long') [-Wformat]
> u + 1, countCases, expectedCountBytesIndirect,
> ^~~~~~~~~~
> 4 warnings generated.
> [..]
> /usr/bin/emcc -DXML_TESTING @CMakeFiles/runtests.dir/includes_C.rsp -fno-strict-aliasing -fvisibility=hidden -std=c99 -MD -MT CMakeFiles/runtests.dir/lib/xmlparse.c.o -MF CMakeFiles/runtests.dir/lib/xmlparse.c.o.d -o CMakeFiles/runtests.dir/lib/xmlparse.c.o -c /libexpat/expat/lib/xmlparse.c
> /libexpat/expat/lib/xmlparse.c:8132:11: warning: format specifies type 'int' but the argument has type 'ptrdiff_t' (aka 'long') [-Wformat]
> bytesMore, (account == XML_ACCOUNT_DIRECT) ? "DIR" : "EXP",
> ^~~~~~~~~
> 1 warning generated.
> [..]
> /usr/bin/em++ -DXML_TESTING @CMakeFiles/runtests_cxx.dir/includes_CXX.rsp -fno-strict-aliasing -fvisibility=hidden -std=c++11 -MD -MT CMakeFiles/runtests_cxx.dir/tests/acc_tests_cxx.cpp.o -MF CMakeFiles/runtests_cxx.dir/tests/acc_tests_cxx.cpp.o.d -o CMakeFiles/runtests_cxx.dir/tests/acc_tests_cxx.cpp.o -c /libexpat/expat/tests/acc_tests_cxx.cpp
> In file included from /libexpat/expat/tests/acc_tests_cxx.cpp:32:
> /libexpat/expat/tests/acc_tests.c:279:11: warning: format specifies type 'unsigned int' but the argument has type 'unsigned long' [-Wformat]
> u + 1, countCases, expectedCountBytesDirect, actualCountBytesDirect);
> ^~~~~
> /libexpat/expat/tests/acc_tests.c:279:18: warning: format specifies type 'unsigned int' but the argument has type 'size_t' (aka 'unsigned long') [-Wformat]
> u + 1, countCases, expectedCountBytesDirect, actualCountBytesDirect);
> ^~~~~~~~~~
> /libexpat/expat/tests/acc_tests.c:288:11: warning: format specifies type 'unsigned int' but the argument has type 'unsigned long' [-Wformat]
> u + 1, countCases, expectedCountBytesIndirect,
> ^~~~~
> /libexpat/expat/tests/acc_tests.c:288:18: warning: format specifies type 'unsigned int' but the argument has type 'size_t' (aka 'unsigned long') [-Wformat]
> u + 1, countCases, expectedCountBytesIndirect,
> ^~~~~~~~~~
> 4 warnings generated.
> [..]
> /usr/bin/emcc -DXML_TESTING @CMakeFiles/runtests_cxx.dir/includes_C.rsp -fno-strict-aliasing -fvisibility=hidden -std=c99 -MD -MT CMakeFiles/runtests_cxx.dir/lib/xmlparse.c.o -MF CMakeFiles/runtests_cxx.dir/lib/xmlparse.c.o.d -o CMakeFiles/runtests_cxx.dir/lib/xmlparse.c.o -c /libexpat/expat/lib/xmlparse.c
> /libexpat/expat/lib/xmlparse.c:8132:11: warning: format specifies type 'int' but the argument has type 'ptrdiff_t' (aka 'long') [-Wformat]
> bytesMore, (account == XML_ACCOUNT_DIRECT) ? "DIR" : "EXP",
> ^~~~~~~~~
> 1 warning generated.
