🐛 Fixed responsive images for .icos

closes #10301

- we allow .ico files for icons, but we cannot resize these specialist files at present

core/server/lib/image/manipulator.js

@@ -40,7 +40,7 @@ const unsafeResizeImage = (originalBuffer, {width, height} = {}) => {
 //       as there has been support added in underlying libvips library https://github.com/lovell/sharp/issues/1372
 //       As for .svg files, sharp only supports conversion to png, and this does not
 //       play well with animated svg files
-const canTransformFileExtension = ext => !['.gif', '.svg', '.svgz'].includes(ext);
+const canTransformFileExtension = ext => !['.gif', '.svg', '.svgz', '.ico'].includes(ext);
 
 const makeSafe = fn => (...args) => {
     try {

core/test/unit/lib/image/manipulator_spec.js

@@ -31,6 +31,12 @@ describe('lib/image: manipulator', function () {
                 false
             );
         });
+        it('returns false for ".ico"', function () {
+            should.equal(
+                manipulator.canTransformFileExtension('.ico'),
+                false
+            );
+        });
     });
 
     describe('cases', function () {