From 0fd2f12728e3eb0f198560ddfb2058370878c7a7 Mon Sep 17 00:00:00 2001
From: Calixte Denizet <calixte.denizet@gmail.com>
Date: Sun, 28 May 2023 14:52:41 +0200
Subject: [PATCH] Don't downscale by steps images which will end up with small
 dimensions (bug 1445735)

---
 src/display/canvas.js         | 10 ++++++++++
 test/pdfs/bug1445735.pdf.link |  1 +
 test/test_manifest.json       | 10 +++++++++-
 3 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 test/pdfs/bug1445735.pdf.link

diff --git a/src/display/canvas.js b/src/display/canvas.js
index ba93deefcc9c7..36a0c86892aea 100644
--- a/src/display/canvas.js
+++ b/src/display/canvas.js
@@ -1188,6 +1188,16 @@ class CanvasGraphics {
       1
     );
 
+    if (width / widthScale <= 5 && height / heightScale <= 5) {
+      // The final image is very small, hence having a poor quality
+      // when rescaling isn't really a problem.
+      return {
+        img,
+        paintWidth: width,
+        paintHeight: height,
+      };
+    }
+
     let paintWidth = width,
       paintHeight = height;
     let tmpCanvasId = "prescale1";
diff --git a/test/pdfs/bug1445735.pdf.link b/test/pdfs/bug1445735.pdf.link
new file mode 100644
index 0000000000000..de8f83e76816e
--- /dev/null
+++ b/test/pdfs/bug1445735.pdf.link
@@ -0,0 +1 @@
+https://bugzilla.mozilla.org/attachment.cgi?id=8958936
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 4d4bb76d063e3..8851a57eb9aa6 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -7713,5 +7713,13 @@
         "value": ["Three", "Five"]
       }
     }
- }
+   },
+   {
+      "id": "bug1445735",
+      "file": "pdfs/bug1445735.pdf",
+      "md5": "a5470d82c1d23eac1fef2fa37f95e980",
+      "rounds": 1,
+      "link": true,
+      "type": "eq"
+   }
 ]