Don't process legacy gifs with imgproxy

Author: davidmz

app/controllers/api/v1/AttachmentsController.js

@@ -241,8 +241,16 @@ export default class AttachmentsController {
       response.width = prv.w;
       response.height = prv.h;
 
-      // With imgproxy, we can resize images (except SVG) and change their format
-      if (useImgProxy && type === 'image' && attachment.fileExtension !== 'svg') {
+      // With imgproxy, we can resize images (except some types) and change
+      // their format
+      if (
+        useImgProxy &&
+        type === 'image' &&
+        // We don't need to resize SVGs
+        attachment.fileExtension !== 'svg' &&
+        // We should not resize (probably) animated legacy GIFs
+        !(attachment.fileExtension === 'gif' && attachment.isLegacyImage)
+      ) {
         let { format } = query;
 
         if (!format) {

app/models.d.ts

@@ -210,6 +210,7 @@ export class Attachment {
   updatedAt: Date;
   userId: UUID;
   postId: UUID | null;
+  isLegacyImage: boolean;
 
   constructor(params: AttachmentParams);
   static create(

app/models/attachment.js

@@ -58,6 +58,12 @@ export function addModel(dbAdapter) {
 
       this.createdAt = params.createdAt;
       this.updatedAt = params.updatedAt;
+
+      /**
+       * This image attachment was created before the 'previews' field was
+       * introduced (i.e. before the v4 API).
+       */
+      this.isLegacyImage = this.mediaType === 'image' && this._previews === null;
     }
 
     get previews() {

test/integration/models/attachment.js

@@ -319,6 +319,7 @@ describe('Attachments', () => {
         previews: expect.it('to equal', { image: { '': { h: 150, w: 150, ext: 'png' } } }),
         width: 150,
         height: 150,
+        isLegacyImage: true,
       });
     });
 
@@ -343,6 +344,7 @@ describe('Attachments', () => {
         }),
         width: 900,
         height: 300,
+        isLegacyImage: true,
       });
     });
 
@@ -369,6 +371,7 @@ describe('Attachments', () => {
         }),
         width: 1500,
         height: 1000,
+        isLegacyImage: true,
       });
     });