XFA - When no fonts in the pdf just use font size as width when measuring text

src/core/xfa/text.js

@@ -59,6 +59,7 @@ class FontInfo {
       fonts.Arial ||
       fonts.ArialMT ||
       Object.values(fonts)[0];
+    if (font && font.regular) {
       const pdfFont = font.regular;
       const info = pdfFont.cssFontInfo;
       const xfaFont = {
@@ -69,6 +70,15 @@ class FontInfo {
       };
       return [pdfFont, xfaFont];
     }
+
+    const xfaFont = {
+      typeface: "Courier",
+      posture: "normal",
+      weight: "normal",
+      size: 10,
+    };
+    return [null, xfaFont];
+  }
 }
 
 class FontSelector {
@@ -124,8 +134,9 @@ class TextMeasure {
     }
 
     const lastFont = this.fontSelector.topFont();
-    const pdfFont = lastFont.pdfFont;
     const fontSize = lastFont.xfaFont.size;
+    if (lastFont.pdfFont) {
+      const pdfFont = lastFont.pdfFont;
       const lineHeight = Math.round(Math.max(1, pdfFont.lineHeight) * fontSize);
       const scale = fontSize / 1000;
 
@@ -144,7 +155,18 @@ class TextMeasure {
 
         this.glyphs.push([0, 0, false, true]);
       }
+      this.glyphs.pop();
+      return;
+    }
 
+    // When we have no font in the pdf, just use the font size as default width.
+    for (const line of str.split(/[\u2029\n]/)) {
+      for (const char of line.split("")) {
+        this.glyphs.push([fontSize, fontSize, char === " ", false]);
+      }
+
+      this.glyphs.push([0, 0, false, true]);
+    }
     this.glyphs.pop();
   }