Scale stroking line width when using a tiling pattern.

src/display/canvas.js

@@ -1145,9 +1145,6 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       consumePath = typeof consumePath !== 'undefined' ? consumePath : true;
       var ctx = this.ctx;
       var strokeColor = this.current.strokeColor;
-      // Prevent drawing too thin lines by enforcing a minimum line width.
-      ctx.lineWidth = Math.max(this.getSinglePixelWidth() * MIN_WIDTH_FACTOR,
-                               this.current.lineWidth);
       // For stroke we want to temporarily change the global alpha to the
       // stroking alpha.
       ctx.globalAlpha = this.current.strokeAlpha;
@@ -1156,10 +1153,21 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
         // for patterns, we transform to pattern space, calculate
         // the pattern, call stroke, and restore to user space
         ctx.save();
+        // The current transform will be replaced while building the pattern,
+        // but the line width needs to be adjusted by the current transform, so
+        // we must scale it. To properly fix this we should be using a pattern
+        // transform instead (see #10955).
+        let transform = ctx.mozCurrentTransform;
+        const scale = Util.singularValueDecompose2dScale(transform)[0];
         ctx.strokeStyle = strokeColor.getPattern(ctx, this);
+        ctx.lineWidth = Math.max(this.getSinglePixelWidth() * MIN_WIDTH_FACTOR,
+                                 this.current.lineWidth * scale);
         ctx.stroke();
         ctx.restore();
       } else {
+        // Prevent drawing too thin lines by enforcing a minimum line width.
+        ctx.lineWidth = Math.max(this.getSinglePixelWidth() * MIN_WIDTH_FACTOR,
+                                 this.current.lineWidth);
         ctx.stroke();
       }
       if (consumePath) {

test/pdfs/.gitignore

@@ -138,6 +138,7 @@
 !issue6413.pdf
 !issue4630.pdf
 !issue4909.pdf
+!scorecard_reduced.pdf
 !issue5084.pdf
 !issue8960_reduced.pdf
 !issue5202.pdf

test/test_manifest.json

@@ -3474,6 +3474,12 @@
       "type": "eq",
       "about": "A CIDFontType0 font with a CFF font that isn't actually CID."
     },
+    {  "id": "scorecard_reduced",
+       "file": "pdfs/scorecard_reduced.pdf",
+       "md5": "aa8ed0827092c963eea64adb718a3806",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "bug921409",
       "file": "pdfs/bug921409.pdf",
       "md5": "920e88dde0f5436ebe0df0281e1c30ca",