[Zlib-devel] zlib 1.2.5

[John Bowler]

I just attempted to validate what I thought I had seen before, using libpng 1.5.0beta22 and zlib 1.2.4.  The results aren't as good as I thought but I didn't see any case of a crash - just failure to link or failure to run (exit code 127).

If I swap out the zlib 1.2.4 DLL with only compiled to use __stdcall (but otherwise identical) the libpng test program, pngtest, simply doesn't run - Cygwin bash shell sees an exit code of 127.

If I attempt to build libpng against the __stdcall DLL it fails at the link step - unresolved cdecl symbols.

This is all as I would expect and is well behaved.

From: Török Edwin
>How about a simple test EXE program for the official zlib DLL?
>It would load the DLL, and do some simple things like call APIs
>(including the gz APIs).
>If you built the DLL wrong / linked to the wrong CRT it will
>crash/report wrong results.

"make testshared" will do that, although it's "make testdll" in win32/Makefile.gcc

Libpng can be used to test the installation:

./configure
make test
.libs/pngtest.exe

The Cygwin ldd can be used to validate that the correct DLL is picked up and pngtest outputs the zlib version number when it runs.

John Bowler <jbowler at acm.org>