png-1.5 fixes

[Thomas Klausner]

In the latest releases, 1.5 and newer, the png library disabled direct
access to its structure members. One is supposed to use the accessor
functions now.
The attached patch (against 2.1, but seems to be still needed looking at the online repository a few minutes ago) fixes the issue.

[Pali (pali)]

And why is this patch needed?

[Thomas Klausner (tk-giga)]

As I said, png-1.5 now forbids access to internal struct members.
Compilerwise, without the patch, it looks like this:
src/video/obj/../png.c: In function 'LoadGraphicPNG':
src/video/obj/../png.c:136: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:215: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:219: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:227: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:273: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:274: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:275: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:276: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:277: error: dereferencing pointer to incomplete type
src/video/obj/../png.c:278: error: dereferencing pointer to incomplete type
src/video/obj/../png.c: In function 'SaveScreenshotPNG':
src/video/obj/../png.c:334: error: dereferencing pointer to incomplete type

[Pali (pali)]

Is this bug same as this https://bugs.launchpad.net/stratagus/+bug/816575 ?

[Thomas Klausner (tk-giga)]

Yes, this patch will fix the issue reported in https://bugs.launchpad.net/stratagus/+bug/816575
Sorry that I overlooked that bug report.

[Pali (pali)]

Your patch file was not possible to apply, because it was for old version of stratagus. It was against file png.c, but in stratagus is now png.cpp (and has other structure). So I modified file png.cpp manually.

Chnages is in this commit: http://bazaar.launchpad.net/~stratagus/stratagus/trunk/revision/7993
Check if all png erros is fixed.