Include replacement characters in Cpdf font subset

These characters aren't (typically) referenced in the PDF and so aren't included in font subsets generated based on the text content. As a result, if an unsupported character is in the document the space occupied by it will be blank when subsetting is enabled.
dompdf · Aug 25, 2022 · 9adb812 · 9adb812
1 parent f5da2fd
commit 9adb812
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/lib/Cpdf.php b/lib/Cpdf.php
@@ -5013,7 +5013,8 @@ function registerText($font, $text)
         }
 
         if (!isset($this->stringSubsets[$font])) {
-            $this->stringSubsets[$font] = [];
+            $base_subset = "\u{fffd}\u{fffe}\u{ffff}";
+            $this->stringSubsets[$font] = $this->utf8toCodePointsArray($base_subset);
         }
 
         $this->stringSubsets[$font] = array_unique(