From 50a16bbdc1361ed6b058200f667fdfdfae82acd9 Mon Sep 17 00:00:00 2001
From: Oliver Vogel <oliver@olivervogel.com>
Date: Wed, 14 Aug 2024 14:57:09 +0200
Subject: [PATCH] Fix lost transparency when converting to GIF format

---
 phpunit.dist.xml                        |  3 +++
 src/Drivers/Gd/Encoders/GifEncoder.php  |  4 ++--
 tests/Feature/Gd/ConvertPngGif.php      | 22 ++++++++++++++++++++++
 tests/Feature/Imagick/ConvertPngGif.php | 22 ++++++++++++++++++++++
 4 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 tests/Feature/Gd/ConvertPngGif.php
 create mode 100644 tests/Feature/Imagick/ConvertPngGif.php

diff --git a/phpunit.dist.xml b/phpunit.dist.xml
index d13b0ce82..e70595aa5 100644
--- a/phpunit.dist.xml
+++ b/phpunit.dist.xml
@@ -4,6 +4,9 @@
     <testsuite name="Unit Tests">
       <directory suffix=".php">./tests/Unit</directory>
     </testsuite>
+    <testsuite name="Feature Tests">
+      <directory suffix=".php">./tests/Feature</directory>
+    </testsuite>
   </testsuites>
   <source>
     <include>
diff --git a/src/Drivers/Gd/Encoders/GifEncoder.php b/src/Drivers/Gd/Encoders/GifEncoder.php
index 875df7871..3c0c6e2ce 100644
--- a/src/Drivers/Gd/Encoders/GifEncoder.php
+++ b/src/Drivers/Gd/Encoders/GifEncoder.php
@@ -6,6 +6,7 @@
 
 use Exception;
 use Intervention\Gif\Builder as GifBuilder;
+use Intervention\Image\Drivers\Gd\Cloner;
 use Intervention\Image\EncodedImage;
 use Intervention\Image\Encoders\GifEncoder as GenericGifEncoder;
 use Intervention\Image\Exceptions\EncoderException;
@@ -26,11 +27,10 @@ public function encode(ImageInterface $image): EncodedImage
             return $this->encodeAnimated($image);
         }
 
-        $gd = $image->core()->native();
+        $gd = Cloner::clone($image->core()->native());
         $data = $this->buffered(function () use ($gd) {
             imageinterlace($gd, $this->interlaced);
             imagegif($gd);
-            imageinterlace($gd, false);
         });
 
         return new EncodedImage($data, 'image/gif');
diff --git a/tests/Feature/Gd/ConvertPngGif.php b/tests/Feature/Gd/ConvertPngGif.php
new file mode 100644
index 000000000..6e5eab7cb
--- /dev/null
+++ b/tests/Feature/Gd/ConvertPngGif.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Feature\Gd;
+
+use Intervention\Image\ImageManager;
+use Intervention\Image\Tests\GdTestCase;
+
+class ConvertPngGif extends GdTestCase
+{
+    public function testConversionKeepsTransparency(): void
+    {
+        $converted = ImageManager::gd()
+            ->read(
+                $this->readTestImage('circle.png')->toGif()
+            );
+
+        $this->assertTransparency($converted->pickColor(0, 0));
+        $this->assertColor(4, 2, 4, 255, $converted->pickColor(25, 25), 4);
+    }
+}
diff --git a/tests/Feature/Imagick/ConvertPngGif.php b/tests/Feature/Imagick/ConvertPngGif.php
new file mode 100644
index 000000000..d9bf11bf5
--- /dev/null
+++ b/tests/Feature/Imagick/ConvertPngGif.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Feature\Imagick;
+
+use Intervention\Image\ImageManager;
+use Intervention\Image\Tests\ImagickTestCase;
+
+class ConvertPngGif extends ImagickTestCase
+{
+    public function testConversionKeepsTransparency(): void
+    {
+        $converted = ImageManager::imagick()
+            ->read(
+                $this->readTestImage('circle.png')->toGif()
+            );
+
+        $this->assertTransparency($converted->pickColor(0, 0));
+        $this->assertColor(4, 2, 4, 255, $converted->pickColor(25, 25), 4);
+    }
+}