Created attachment 200076 [details] [review]
Don't deflateSetHeader/inflateGetHeader on OS versions that lack them

gzlibdecompressor.c and gzlibcompressor.c presume that if zlib >=1.2.3 is installed, deflateSetHeader and inflateGetHeader are present. Mac OS X 10.4.x (Tiger) ships with a zlib 1.2.3 build that doesn't export those two symbols, so building glib under OS X 10.4.x fails. 10.6.x (Snow Leopard) ships with a zlib 1.2.3 build that DOES have the symbols. I believe that 10.5.x (Leopard) has the symbols, but I'm not sure. 10.7.x (Snow Leopard) ships with zlib 1.2.5.

The existing code that uses deflateSetHeader/inflateGetHeader is presently #if'd so that it becomes a no-op under Windows with zlib <1.2.4. I am attaching a patch that does the same for affected Mac OS X versions.

My patch adds a second #if rather than integrating with the existing #if, simply to keep that line from getting too long and ugly.

XCode 3.2.6 always defines __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__, but XCode 2.5 only defines it if a deployment target has been explicitly specified. Therefore, my patch defaults to not using deflateSetHeader/inflateGetHeader if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ is not defined, unless the zlib version is >=1.2.5. If the zlib version is >=1.2.5, it uses deflateSetHeader/inflateGetHeader even under Tiger; this allows someone to build against a locally compiled copy of zlib and get the deflateSetHeader/inflateGetHeader functionality.