Skip shrink-on-load for multi-page WebP #2714

Author: lovell

docs/changelog.md

@@ -4,6 +4,11 @@
 
 Requires libvips v8.10.6
 
+### v0.28.3 - TBD
+
+* Skip shrink-on-load for multi-page WebP.
+  [#2714](https://github.com/lovell/sharp/issues/2714)
+
 ### v0.28.2 - 10th May 2021
 
 * Allow `withMetadata` to set `density`.

src/pipeline.cc

@@ -227,7 +227,7 @@ class PipelineWorker : public Napi::AsyncWorker {
         xshrink == yshrink && xshrink >= 2 * shrink_on_load_factor &&
         (inputImageType == sharp::ImageType::JPEG || inputImageType == sharp::ImageType::WEBP) &&
         baton->gamma == 0 && baton->topOffsetPre == -1 && baton->trimThreshold == 0.0 &&
-        image.width() > 3 && image.height() > 3
+        image.width() > 3 && image.height() > 3 && baton->input->pages == 1
       ) {
         if (xshrink >= 8 * shrink_on_load_factor) {
           xfactor = xfactor / 8;