From 308a79daabcd191d1f1ba562c091facfc9b33f79 Mon Sep 17 00:00:00 2001
From: Grimmauld <Grimmauld@grimmauld.de>
Date: Sat, 17 May 2025 11:46:19 +0200
Subject: [PATCH] perl540Packages.SDL: fix build

---
 .../perl-modules/sdl-compat-bit-depth.patch      | 16 ++++++++++++++++
 pkgs/top-level/perl-packages.nix                 |  3 +++
 2 files changed, 19 insertions(+)
 create mode 100644 pkgs/development/perl-modules/sdl-compat-bit-depth.patch

diff --git a/pkgs/development/perl-modules/sdl-compat-bit-depth.patch b/pkgs/development/perl-modules/sdl-compat-bit-depth.patch
new file mode 100644
index 000000000000..8077828f4224
--- /dev/null
+++ b/pkgs/development/perl-modules/sdl-compat-bit-depth.patch
@@ -0,0 +1,16 @@
+diff --git a/t/core_surface.t b/t/core_surface.t
+index 897536b6..03efa859 100644
+--- a/t/core_surface.t
++++ b/t/core_surface.t
+@@ -51,7 +51,10 @@ is( $image->h, 32, 'image has height' );
+ 
+ my $pixel_format = $image->format;
+ isa_ok( $pixel_format, 'SDL::PixelFormat' );
+-is( $pixel_format->BitsPerPixel,  8,   ' BitsPerPixel' );
++# the bitmap has a bitdepth of 4
++# SDL_classic could not allocate less than full bytes per pixel
++# sdl12-compat returns the actual bit depth of the image here
++is( $pixel_format->BitsPerPixel,  4,   ' BitsPerPixel' );
+ is( $pixel_format->BytesPerPixel, 1,   ' BytesPerPixel' );
+ is( $pixel_format->Rloss,         8,   ' Rloss' );
+ is( $pixel_format->Gloss,         8,   ' Gloss' );
diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index d0b49254e8ec..97119f7d3416 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -30215,6 +30215,9 @@ with self;
     patches = [
       # https://github.com/PerlGameDev/SDL/pull/304
       ../development/perl-modules/sdl-modern-perl.patch
+      # sdl-compat correctly reports the bit depth of the test image,
+      # while SDL_classic rounded to the next byte
+      ../development/perl-modules/sdl-compat-bit-depth.patch
       (fetchpatch {
         url = "https://aur.archlinux.org/cgit/aur.git/plain/surface-xs-declare-calc-offset-earlier.diff?h=perl-sdl&id=d4b6da86d33046cde0e84fa2cd6eaccff1667cab";
         hash = "sha256-dQ2O4dO18diSAilSZrZj6II+mBuKKI3cx9fR1SJqUvo=";