Merge upstream.

src/fonts.js

@@ -1791,6 +1791,10 @@ var Font = (function FontClosure() {
               var i = unassignedUnicodeItems[j];
               while (unusedUnicode in usedUnicodes)
                 unusedUnicode++;
+              var cid = i + 1;
+              // override only if unicode mapping is not specified
+              if (!(cid in toUnicode))
+                toUnicode[cid] = unusedUnicode;
               glyphs[i].unicode = unusedUnicode++;
             }
             this.useToUnicode = true;

test/pdfs/issue919.pdf.link

@@ -0,0 +1 @@
+http://agb.traviangames.com/Travian_AR_Terms.pdf

test/test_manifest.json

@@ -341,8 +341,15 @@
        "pageLimit": 3,
        "type": "eq"
     },
-    {
+    {  "id": "issue919",
-      "id": "aboutstacks",
+       "file": "pdfs/issue919.pdf",
+       "md5": "3a1716a512aca4d7a8d6106bd4885d14",
+       "rounds": 1,
+       "link": true,
+       "pageLimit": 3,
+       "type": "eq"
+    },
+    {  "id": "aboutstacks",
       "file": "pdfs/aboutstacks.pdf",
       "md5": "6e7c8416a293ba2d83bc8dd20c6ccf51",
       "rounds": 1,