[CIDFontType2] Map characters missing in toUnicode to the private use area (bug 1028735 and issue 4881)

src/core/fonts.js

@@ -2473,6 +2473,7 @@ var Font = (function FontClosure() {
     var toUnicode = properties.toUnicode;
     var isSymbolic = !!(properties.flags & FontFlags.Symbolic);
     var isIdentityUnicode = properties.isIdentityUnicode;
+    var isCidFontType2 = (properties.type === 'CIDFontType2');
     var newMap = Object.create(null);
     var toFontChar = [];
     var usedFontCharCodes = [];
@@ -2483,12 +2484,18 @@ var Font = (function FontClosure() {
       var fontCharCode = originalCharCode;
       // First try to map the value to a unicode position if a non identity map
       // was created.
-      if (!isIdentityUnicode && toUnicode[originalCharCode] !== undefined) {
+      if (!isIdentityUnicode) {
+        if (toUnicode[originalCharCode] !== undefined) {
           var unicode = toUnicode[fontCharCode];
           // TODO: Try to map ligatures to the correct spot.
           if (unicode.length === 1) {
             fontCharCode = unicode.charCodeAt(0);
           }
+        } else if (isCidFontType2) {
+          // For CIDFontType2, move characters not present in toUnicode
+          // to the private use area (fixes bug 1028735 and issue 4881).
+          fontCharCode = nextAvailableFontCharCode;
+        }
       }
       // Try to move control characters, special characters and already mapped
       // characters to the private use area since they will not be drawn by

test/pdfs/.gitignore

@@ -56,6 +56,7 @@
 !bug903856.pdf
 !bug850854.pdf
 !bug866395.pdf
+!bug1028735.pdf
 !basicapi.pdf
 !mixedfonts.pdf
 !shading_extend.pdf

test/test_manifest.json

@@ -176,6 +176,15 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "bug1028735",
+       "file": "pdfs/bug1028735.pdf",
+       "md5": "5d1a2a87d176ff3b24e66af3cb2365be",
+       "rounds": 1,
+       "link": false,
+       "firstPage": 1,
+       "lastPage": 1,
+       "type": "eq"
+    },
     {  "id": "issue1512",
        "file": "pdfs/issue1512.pdf",
        "md5": "41a19fe03d522346ee3baa732403fca4",