[jdk8u-dev] RFR: 8348598: Update Libpng to 1.6.47

[Sergey Bylokhov]

On Tue, 2 Dec 2025 13:39:22 GMT, Zdenek Zambersky <zzambers at openjdk.org> wrote:

> This backport updates bundled libpng to 1.6.47.
> There are some differences to jdk11:
> - there is no `libpng.md` in JDK 8, equivalent changes were done to `THIRD_PARTY_README`
> - changes to `UPDATING.txt` were excluded (this file is not present in 8)
> - changes to `/lib/Awt2dLibraries.gmk` were excluded, as build system of jdk 8 is different and there is no support for `DISABLED_WARNINGS_*` there
> 
> Otherwise, when it comes to library source files (libpng dir), changes applied cleanly (although they have different path).
> I have also tried to use diff to compare contents of libpng directory (after update to 1.6.47) in jdk 8 and jdk 11, there are same, except for `UPDATING.txt`, which is only present in jdk 11.
> 
> **Motivation:**
> - to fix one build error on macos-15 (it no longer ships with `fp.h`)
> 
>  In file included from /Users/runner/work/jdk8u-dev/jdk8u-dev/jdk/jdk/src/share/native/sun/awt/libpng/png.c:42:
> /Users/runner/work/jdk8u-dev/jdk8u-dev/jdk/jdk/src/share/native/sun/awt/libpng/pngpriv.h:552:16: fatal error: 'fp.h' file not found
>   552 | #      include <fp.h>
>       |                ^~~~~~
> 1 error generated.
> gmake[2]: *** [lib/Awt2dLibraries.gmk:1256: /Users/runner/work/jdk8u-dev/jdk8u-dev/jdk/build/macos-x64/jdk/objs/libsplashscreen/png.o] Error 1
> 
> - to prepare for [JDK-8372534](https://bugs.openjdk.org/browse/JDK-8372534) (update to 1.6.51) in the future
> 
> Testing:
> - testing in GHA: **OK** (failures of `TestCPUAwareness.java` are [unrelated](https://github.com/openjdk/jdk8u-dev/pull/727))
> - manually tested `jdk/test/java/awt/SplashScreen` (rhel-8 VM / tigervnc): **OK**

Please confirm that the splashscreen tests works fine on macOS, Linux, and Windows. `test/java/awt/SplashScreen/*`

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PR Comment: https://git.openjdk.org/jdk8u-dev/pull/729#issuecomment-3667410047