Merge pull request #15251 from Snuffleupagus/thumbnail-setImage-small

Ignore too small page-canvases in `PDFThumbnailView.setImage`
mozilla · Jul 31, 2022 · f9c593d · f9c593d
2 parents 7798252 + 5b50a50
commit f9c593d
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/web/pdf_thumbnail_view.js b/web/pdf_thumbnail_view.js
@@ -352,13 +352,17 @@ class PDFThumbnailView {
     if (this.renderingState !== RenderingStates.INITIAL) {
       return;
     }
-    const { thumbnailCanvas: canvas, pdfPage } = pageView;
+    const { thumbnailCanvas: canvas, pdfPage, scale } = pageView;
     if (!canvas) {
       return;
     }
     if (!this.pdfPage) {
       this.setPdfPage(pdfPage);
     }
+    if (scale < this.scale) {
+      // Avoid upscaling the image, since that makes the thumbnail look blurry.
+      return;
+    }
     this.renderingState = RenderingStates.FINISHED;
     this._convertCanvasToImage(canvas);
   }