diff --git a/docs/contributing/how-to-update-third-party-library.md b/docs/contributing/how-to-update-third-party-library.md index f2fddd8d76..ac885e2391 100644 --- a/docs/contributing/how-to-update-third-party-library.md +++ b/docs/contributing/how-to-update-third-party-library.md @@ -116,11 +116,12 @@ to perform an extra step after merging the new version (and before committing your changes): Create a temporary build directory and run libpng configure from it using ---with-libpng-prefix=wx_ option. Then run "make" (actually just "make png.lo" -is sufficient as we don't really need to build the library) to create -pnglibconf.h and pngprefix.h files in the build directory. And copy these -files to src/png subdirectory of the wxWidgets source tree, overwriting the -versions there. +--with-libpng-prefix=wx_ option. Then run `make pnglibconf.h pngprefix.h` +to create these files in the build directory. Next, search for the line +containing `PNG_ZLIB_VERNUM` in the `pnglibconf.h` and set it to 0 to disable +zlib version checks (this looks dangerous but seems to be unavoidable with the +current build system). And then, finally, copy these files to src/png +subdirectory of the wxWidgets source tree, overwriting the versions there. Notice that config.h generated by libpng configure is not used, we build it without -DHAVE_CONFIG_H as it works just fine without it on any ANSI C system diff --git a/src/png b/src/png index 834401fec4..8129d71d80 160000 --- a/src/png +++ b/src/png @@ -1 +1 @@ -Subproject commit 834401fec480a27e542c2861fc7c26700cc5c5fe +Subproject commit 8129d71d80d1274b62949b07c4f2aef728c20fd9