Saving WebP images in GD requires a True Color palette

https://stackoverflow.com/questions/39292617/fatal-error-paletter-image-not-supported-by-webp/47469726#47469726

diff --git a/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php b/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php
index 674cf649bbe9dbd3b4a692374f7021890bca18f0..6e654a8aaaf33abd6dd0391bef86a2f08d55b6d8 100644 (file)
--- a/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php
+++ b/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php
@@ -402,6 +402,7 @@ class GDImageAdapter implements IImageAdapter, IWebpImageAdapter
         } elseif ($this->type == \IMAGETYPE_PNG) {
             \imagepng($image);
         } elseif ($this->type == \IMAGETYPE_WEBP) {
+            \imagepalettetotruecolor($image);
             \imagewebp($image);
         } elseif (\function_exists('imageJPEG')) {
             \imagejpeg($image, null, 90);
@@ -593,6 +594,7 @@ class GDImageAdapter implements IImageAdapter, IWebpImageAdapter
                 break;
 
             case "webp":
+                \imagepalettetotruecolor($image);
                 \imagewebp($image, null, $quality);
                 break;