From 623e6d94764bcde883ccab83a4fc5f278df96e00 Mon Sep 17 00:00:00 2001
From: calixteman <calixte.denizet@gmail.com>
Date: Sun, 21 Jun 2026 22:18:50 +0200
Subject: [PATCH] Reset alpha before drawing a colored glyph in type 3 font

It fixes #21430.
---
 src/display/canvas.js         |  8 ++++++++
 test/pdfs/issue21430.pdf.link |  1 +
 test/test_manifest.json       | 10 ++++++++++
 3 files changed, 19 insertions(+)
 create mode 100644 test/pdfs/issue21430.pdf.link

diff --git a/src/display/canvas.js b/src/display/canvas.js
index 89af70089..01a9a2f7d 100644
--- a/src/display/canvas.js
+++ b/src/display/canvas.js
@@ -2965,6 +2965,14 @@ class CanvasGraphics {
         warn(`Type3 character "${glyph.operatorListId}" is not available.`);
       } else if (this.contentVisible) {
         this.save();
+        // A d0 (setCharWidth) glyph is colored (see Table 113 in pdf 1.7 specs)
+        // unlike a d1 glyph painted as a stencil mask with the current fill
+        // color. The constant alphas (ca/CA) are the opacity of that current
+        // color, so they must not attenuate a d0 glyph.
+        if (operatorList.fnArray[0] === OPS.setCharWidth) {
+          current.fillAlpha = current.strokeAlpha = 1;
+          ctx.globalAlpha = 1;
+        }
         ctx.scale(fontSize, fontSize);
         ctx.transform(...fontMatrix);
         this.executeOperatorList(operatorList);
diff --git a/test/pdfs/issue21430.pdf.link b/test/pdfs/issue21430.pdf.link
new file mode 100644
index 000000000..ed7e4d1af
--- /dev/null
+++ b/test/pdfs/issue21430.pdf.link
@@ -0,0 +1 @@
+https://github.com/user-attachments/files/28821514/xxx.pdf
diff --git a/test/test_manifest.json b/test/test_manifest.json
index e887360d8..08b6dfdbf 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -14429,5 +14429,15 @@
     "type": "eq",
     "annotations": true,
     "forms": true
+  },
+  {
+    "id": "issue21430",
+    "file": "pdfs/issue21430.pdf",
+    "md5": "e317f63bdfd6f3d1939a52c983379454",
+    "rounds": 1,
+    "link": true,
+    "firstPage": 1,
+    "lastPage": 1,
+    "type": "eq"
   }
 ]