Use canvas context text primitives when the font file is missing

It fixes #20065.

The only to get a path (from the path generator) is when the font is embedded.
So when we need a path (disableFontFace: true or when we want to use a pattern for stroking/filling), it's impossible
to fulfil.

Author: calixteman

src/display/canvas.js

@@ -1625,6 +1625,9 @@ class CanvasGraphics {
     const newPath = new Path2D();
     const invTransf = ctx.getTransform().invertSelf();
     for (const { transform, x, y, fontSize, path } of paths) {
+      if (!path) {
+        continue; // Skip empty paths.
+      }
       newPath.addPath(
         path,
         new DOMMatrix(transform)
@@ -1768,15 +1771,16 @@ class CanvasGraphics {
 
     let path;
     if (
-      font.disableFontFace ||
-      isAddToPathSet ||
-      patternFill ||
-      patternStroke
+      (font.disableFontFace ||
+        isAddToPathSet ||
+        patternFill ||
+        patternStroke) &&
+      !font.missingFile
     ) {
       path = font.getPathGenerator(this.commonObjs, character);
     }
 
-    if (font.disableFontFace || patternFill || patternStroke) {
+    if (path && (font.disableFontFace || patternFill || patternStroke)) {
       ctx.save();
       ctx.translate(x, y);
       ctx.scale(fontSize, -fontSize);

test/pdfs/.gitignore

@@ -733,3 +733,4 @@
 !firefox_logo.pdf
 !issue20062.pdf
 !issue20102.pdf
+!issue20065.pdf

test/pdfs/issue20065.pdf

@@ -12213,5 +12213,13 @@
         "popupRef": "27R"
       }
     }
+  },
+  {
+    "id": "issue20065",
+    "file": "pdfs/issue20065.pdf",
+    "md5": "39ad13514d0b0108e4ae42f4b1422839",
+    "rounds": 1,
+    "disableFontFace": true,
+    "type": "eq"
   }
 ]