Fix: skip generating thumbnails for APNG Backported from #5113

266f3ade0d42b64fabe0452cc485eb1e1c2e49e9

Cohee <18619528+Cohee1207@users.noreply.github.com>

src/endpoints/image-metadata.js+1 -1 Viewed

  * @param {Buffer} buffer The file buffer.
  * @returns {boolean}
  */
 export function isAnimatedApng(buffer) {
     return buffer.subarray(0, 200).includes('acTL');
+}

src/endpoints/thumbnails.js+11 -1 Viewed

 import { imageSize as sizeOf } from 'image-size';
 import { getConfigValue, invalidateFirefoxCache } from '../util.js';
 import { getThumbnailResolution, isAnimatedWebP, thumbnailDimensions as dimensions, isAnimatedApng } from './image-metadata.js';
 import { ResizeStrategy } from '@jimp/plugin-resize';
 export const publicRouter = express.Router();

+            }
+        }
 +        // For PNG files, check if they are actually APNGs.
 +        if (fileExtension === '.png' && isKnownAnimated !== false) {
 +            const buffer = fs.readFileSync(pathToOriginalFile);
 +            const isAnimated = isAnimatedApng(buffer);
 +            if (isAnimated) {
 +                // The client is expected to handle it.
 +                return { path: null, aspectRatio: null, resolution: null };
 +            }
 +        }
++
         if (SKIPPED_EXTENSIONS.has(fileExtension)) {
             return { path: null, aspectRatio: null, resolution: null };
+        }