Sync gd 2 4 by pierrejoye · Pull Request #22532 · php/php-src

pierrejoye · 2026-07-01T11:19:38Z

Sync php's libgd to current GD's master, which will be 2.4.0

New APIs

2D vector graphic APIs using FT raster (standalone version)
- Feature/vector2d 2.4 libgd/libgd#1015
Share compisitions with existing gd's functions
optionally allow to replace exising composition OPs to be replace by the new accurate ones.
ad gdImageRead* APIs, to read an image from a file/stream, codec selected using known binary signature
Codecs Added:
QOI full support (bundled/no dep)
#796 Initial QOI support, read and write libgd/libgd#1005
JXL + JXL animation
Webp animation and full formats support
Full animated WebP read/write support libgd/libgd#1001
Full TIFF support
Initial TIFF multiple pages support libgd/libgd#1010
GIF animations read and write + Full GIF support
BMP All formats but OS/2
Feature/bmpfullsupport libgd/libgd#999
AVIF animation read and write
UltraHDR support, using libultrahdr, read and write as standalone, or read SD image as gdImage
Feature/ultrahdr libgd/libgd#1003
for formats supporting it, raw metadata read/write APIs. can be then be processed and pushed back)
- Feature/metadata libgd/libgd#1002

Updated/Fixed

Color Match improvement using Lab* + Delta-E and actual % as input
Fix and improve freetype rendering and merge both php's libgd + libgd "new encoding"
. Fix RAMQ rendering
All codecs with conformance tests (upstream, C)
Perceptual difference (upstream C, will be exposed so php's tests can rely on it

WIP:

This is the 1st phase, to ensure it builds correctly in php's CI. And hopefully the new deps will be added as well.

The next phases is to expose the new APIs in php's.

…d color map

…ns (90% rewrite). update reference images (buggy before) for tests

…ns usuable, using linear RGBA instead of previous weird squared distance

…p's config. also move it to the right place

pierrejoye · 2026-07-06T01:59:46Z

@bukka btw, as it seems you have been added as reviewer because of main/php_compat.h being touch, I wonder if they could be moved to the extension folder instead.

besides it is buggy now, gd is inside xml ifdef and some symbols seem not to exist (will double check those). It can be separate PR. If can ease maintenance of it, maybe generate it, as declaration macros are needed too for visibility. thoughts?

pierrejoye · 2026-07-06T04:14:30Z

@edorian hello :)

Not sure what you use, upstream has a larger tests suite, including codecs corpus on demand (conformance tests), not included here (and won't be) as the assets are 200M. I have the full fuzzing too but need to clean it a bit before I enable in libgd's CI. Maybe that helps too

pierrejoye · 2026-07-06T07:32:29Z

for reference, slowly drafting the RFC here

edorian · 2026-07-06T11:07:18Z

@edorian hello :)

Hey 👋, very long time no see.

Not sure what you use, upstream has a larger tests suite, including codecs corpus on demand (conformance tests), not included here (and won't be) as the assets are 200M. I have the full fuzzing too but need to clean it a bit before I enable in libgd's CI. Maybe that helps too

Great input. I've added that to my workflows. I should be able to get some results to you and bukka later today.

edorian

Hi again,

Quoting @bukka :

I don't have time for a deep review but I asked Volker to do a proper AI audit of the added code. We should do at least that and make sure there are no major finding in the added code.

I've done what I think makes sense in terms of AI review. The expected findings first:

The sync is faithful and backdoor-free. Bundled ext/gd/libgd matches upstream libgd master byte-for-byte (verified two ways: file-diff + an 89-agent classification); font tables are numerically identical; only 2 non-libgd files change (CODEOWNERS, php_compat.h); all 66 commits are on-topic (nothing touches files outside ext/gd + those 2).
No prior security patch was dropped. We checked the 30 highest-value CVE-class libgd fixes (2016–2026) — all preserved (0 dropped). This is the main risk of a wholesale re-vendor, and it did not happen.
Under ASan/UBSan: upstream's full 246-test suite passes clean; PHP's ext/gd .phpt suite is 310/320 on a default build with 0 sanitizer hits; corpus + fuzz found no new memory-corruption bugs beyond the two below.

I've included 5 comments on findings made along the way

Even if the issue is in the libgd , then we shouldn't merge this until this if fixed there or on this PR.

There are three more (low to medium) findings on libgd that I didn't include here that might make sense to look at in private first?

I'll send you two a mail with the details.

I've done a brief manual validation, but you're way more knowledgeable on this than I am. If a finding is invalid, just say so and close the comment.

pierrejoye · 2026-07-06T17:35:04Z

@edorian I added the initial (relatively) small fuzzing, you can see the workflow in https://github.com/libgd/libgd/blob/master/.github/workflows/fuzz-codecs.yml

docs to add more here https://github.com/libgd/libgd/blob/master/tests/fuzzing/README.md, and existing ones in the same tests folder

This reverts commit add1983. wrong changes. only pkg config needed

edorian · 2026-07-07T23:38:27Z

Great. All public feedback processed. Let me know if there is anything I can help with still @bukka. You're also on /cc for the other discussion.

So 👍 from my side so far

TimWolla

please refrain yourself to slip in changes not related to the topic at hand. Adding you as code owner could be done in a separate PR.

@pierrejoye I agree with David here. Can you commit the CODEOWNER change (and any other change that is not purely related to the GD sync) separately, please?

pierrejoye · 2026-07-09T06:14:02Z

please refrain yourself to slip in changes not related to the topic at hand. Adding you as code owner could be done in a separate PR.

@pierrejoye I agree with David here. Can you commit the CODEOWNER change (and any other change that is not purely related to the GD sync) separately, please?

reverted.

Resolved

TimWolla · 2026-07-09T10:39:28Z

Thanks.

As for the sync itself: Is it possible to automate the sync with a script similar to https://github.com/php/php-src/blob/master/ext/lexbor/patches/update-lexbor.sh?

This would make verification and future synchronization much easier. The sync should then also happen in a single commit, since individual commits for individual components will result in an inconsistent state for intermediate commits.

TimWolla · 2026-07-09T10:40:10Z

+	/* Keep PHP's historical PNG warning text while bundled gd_png.c stays
+	 * identical to upstream libgd. */
+	if (strcmp(format, "gd-png: fatal libpng error: %s\n") == 0) {
+		format = "gd-png:  fatal libpng error: %s";
+	} else if (strncmp(format, "gd-png error: setjmp returns error condition",
+			sizeof("gd-png error: setjmp returns error condition") - 1) == 0) {
+		format = "gd-png error: setjmp returns error condition";
+	}


I don't think this logic is necessary, there is explicitly no BC guarantee for error messages in PHP.

Right, but some phpt rely on those. So I keep them the same so tests don't need updates.

pierrejoye · 2026-07-10T03:40:13Z

Thanks.

As for the sync itself: Is it possible to automate the sync with a script similar to https://github.com/php/php-src/blob/master/ext/lexbor/patches/update-lexbor.sh?

This would make verification and future synchronization much easier. The sync should then also happen in a single commit, since individual commits for individual components will result in an inconsistent state for intermediate commits.

Not totally yet. There are a few things I like to change in ext/gd/libgd first to make it possible. The target is to do not need any script at all. Anything that needs to be specific to php will be separate files.

The issue now is that we include php's config and other similar headers as well in ext/gd/libgd/, for the php's versions of various libc functions etc. That makes automatic sync more tricky, especially for the APIs transferring memory ownership f.e., or having slighly different signatures. Some uses different types as well, making build not warning free or may affect behaviors in some edge cases.

But now, to achieve this will be significantly easier. Adding specific defines, or thin wrappers for those, upstream using the standard libc and php's use php's ones. But that is not the scope of this PR. This PR is soleny about having 2.4 synced here, tests and audits green.

I (desperately) wait for this PR to be approved, while it is approved by the last reviewer on internals, by Ilia, and indeed myself lol ;-)

The actual PR for 2.4 additions in PHP is what matters here, see https://wiki.php.net/rfc/ext-gd-2.4. Still drafting it, but it already gives a good idea.

pierrejoye · 2026-07-12T11:06:49Z

just a head up :)

@bukka possible to approve here too? approved on internals but it does make it approved here (I try to stick to the process). All issues reported here or by Volker solved but the sec, or sec-like, ones which will be done using the normal fix only and merge to active branches separately in coordination with the respective RMs.

Alternatively I can merge tomorrow, so I can push the actual 8.6 addition PR then. is that ok? :)

pierrejoye · 2026-07-14T14:52:39Z

ok, missed alpha2..... We have an issue with PRs handling, and security+RMs. I will check out what could work better and propose something to internals

pierrejoye added 30 commits June 29, 2026 20:50

Use advanced PNG options for imagepng

49adc4f

Synchronize bundled PNG implementation with libgd 2.4

9b7f9d0

sync gd_jpeg

30f7bec

add qoi

edf6950

more match between upstream<>php, add no-op BGD_DECLARE

d886dc4

sync gd_webp

483c68c

sync gd_avif

90bce49

sync gd_jxl

2b72144

sync gd_jxl

d0cd0ab

sync gd tga

29491bf

add webmux to config.*. preserve the warnings in php's version. add g…

5a5be00

…d color map

sync gd heif

147a1cb

ws

70b1d07

sync gd wbmp

1430213

sync gd BMP

26c65ed

fix signature, step 1

2a6aa88

sync uhdr, need some other parts in the process. Sync gd interpolatio…

3dfe937

…ns (90% rewrite). update reference images (buggy before) for tests

sync gd rotate

2ea92a0

sync gd_security

3be4900

sync topal, keep BC for image tc to palette

93bcaba

sync gd_crop, this is actually a BC break, or more make these functio…

f7cb0c7

…ns usuable, using linear RGBA instead of previous weird squared distance

sync matrix/transform/filter

2ad8070

sync grouped gd.h, gd2, xbm, tiff

5d58b0a

sync gdPngGetVersionString to libgd, and check for its existing in ph…

02a7e18

…p's config. also move it to the right place

missing that mapping for gdPngGetVersionString

194706a

add gdImageRead*, add BGD_DECLARE to gif in

f9ac483

reorder and add missing in php_compat

1d06062

sync gif in/out, add gd_filename

d49cb93

sync gd_io_dp

c34edb2

sync gd_io_ss

8e07d95

pierrejoye added 2 commits July 6, 2026 09:30

move public headers in gd.h and gd_vector_2d.h, group by codecs

626bb6f

some more sync/alignments

b032547

edorian reviewed Jul 6, 2026

View reviewed changes

Comment thread ext/gd/gd.c

Comment thread ext/gd/config.m4

Comment thread ext/gd/gd.c

Comment thread main/php_compat.h

Comment thread ext/gd/config.w32

pierrejoye added 3 commits July 7, 2026 10:01

align with 1.x requirement (and config.w32)

add1983

Revert "align with 1.x requirement (and config.w32)"

3fdf781

This reverts commit add1983. wrong changes. only pkg config needed

bump minimum version to 1.0.0

839381b

TimWolla previously requested changes Jul 8, 2026

View reviewed changes

revert... procederal request.

cf75437

TimWolla reviewed Jul 9, 2026

View reviewed changes

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Sync php's libgd to current GD's master, which will be 2.4.0

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