GNOME Bugzilla – Bug 662827
Compression detection code in xmlIO.c is naughty
Last modified: 2021-07-05 13:26:15 UTC
There are two problems with the code in __xmlParserInputBufferCreateFilename that tries to determine wither a gzipped file is compressed. First, it tries to call gzdirect on Mac OS X versions whose zlib doesn't export that symbol. This is the same situation that glib has with other symbols in zlib; see bug #662826 for more details. The summary is that some versions ship with zlib 1.2.3 but don't export gzdirect, others ship with a zlib 1.2.3 build that does export gzdirect. Second, the code that's compiled in for zlib <1.2.3 looks like a ticking time bomb. If it's compiled on a machine with zlib <1.2.3, but then run on a machine with zlib >=1.2.4, it will most likely crash when reading gzipped input. This is notable because it means you can't just switch to the pre-1.2.3 code when compiling under OS X 10.4, because OS X 10.7 ships with zlib 1.2.5.
GNOME is going to shut down bugzilla.gnome.org in favor of gitlab.gnome.org. As part of that, we are mass-closing older open tickets in bugzilla.gnome.org which have not seen updates for a longer time (resources are unfortunately quite limited so not every ticket can get handled). If you can still reproduce the situation described in this ticket in a recent and supported software version, then please follow https://wiki.gnome.org/GettingInTouch/BugReportingGuidelines and create a new ticket at https://gitlab.gnome.org/GNOME/libxml2/-/issues/ Thank you for your understanding and your help.