Mesa (master): configure.ac: Reduce zlib requirement from 1.2.8 to 1.2.3.

[Emil Velikov]

Module: Mesa
Branch: master
Commit: ad69b037b1ca38390fad440189541e49b3f48f14
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ad69b037b1ca38390fad440189541e49b3f48f14

Author: Chuck Atkins <chuck.atkins at kitware.com>
Date:   Thu Jun  8 13:11:32 2017 -0400

configure.ac: Reduce zlib requirement from 1.2.8 to 1.2.3.

Testing with zlib versions 1.2.{3,4,5,6,7,8} showed no difference in
functionality, correctness, or zlib API usage and 1.2.3 is the oldest
version available in still actively deployed production Linux
distributions (RHEL/CentOS 6 and SuSE 11).

Build 17.1.1 against the system supplied zlib-devel packages for 1.2.3
in EL6 and 1.2.7 on EL7. I then swapped out the zlib version at runtime
via LD_LIBRARY_PATH with ones build from the release tarballs from
zlib.net

Testwise - I ran the piglit shader profile with --quick addded to the
tests since I figured that would exercise the shader cache, which would
in turn use zlib.

Signed-off-by: Chuck Atkins <chuck.atkins at kitware.com>
Cc: 17.1 <mesa-stable at lists.freedesktop.org>
Cc: Timothy Arceri <tarceri at itsqueeze.com>
Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>
[Emil Velikov: add hunk about version/piglit testing]
Acked-by: Emil Velikov <emil.velikov at collabora.com>

---

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 82a1bd6cd1..6c67d27084 100644
--- a/configure.ac
+++ b/configure.ac
@@ -97,7 +97,7 @@ XSHMFENCE_REQUIRED=1.1
 XVMC_REQUIRED=1.0.6
 PYTHON_MAKO_REQUIRED=0.8.0
 LIBSENSORS_REQUIRED=4.0.0
-ZLIB_REQUIRED=1.2.8
+ZLIB_REQUIRED=1.2.3
 
 dnl LLVM versions
 LLVM_REQUIRED_GALLIUM=3.3.0