Removes duplicate entries after reading cmap table

src/core/fonts.js

@@ -3077,6 +3077,17 @@ var Font = (function FontClosure() {
           error('cmap table has unsupported format: ' + format);
         }
 
+        // removing duplicate entries
+        mappings.sort(function (a, b) {
+          return a.charcode - b.charcode;
+        });
+        for (var i = 1; i < mappings.length; i++) {
+          if (mappings[i - 1].charcode === mappings[i].charcode) {
+            mappings.splice(i, 1);
+            i--;
+          }
+        }
+
         return {
           platformId: potentialTable.platformId,
           encodingId: potentialTable.encodingId,
@@ -3758,7 +3769,6 @@ var Font = (function FontClosure() {
       if (isTrueType) {
         var isGlyphLocationsLong = int16([tables.head.data[50],
                                           tables.head.data[51]]);
-
         sanitizeGlyphLocations(tables.loca, tables.glyf, numGlyphs,
                                isGlyphLocationsLong, hintsValid, dupFirstEntry);
       }

test/pdfs/.gitignore

@@ -50,6 +50,7 @@
 !noembed-eucjp.pdf
 !noembed-sjis.pdf
 !vertical.pdf
+!issue3025.pdf
 !issue2099-1.pdf
 !issue3371.pdf
 !issue2956.pdf

test/test_manifest.json

@@ -1363,6 +1363,12 @@
       "rounds": 1,
       "type": "eq"
     },
+    {  "id": "issue3025",
+      "file": "pdfs/issue3025.pdf",
+      "md5": "8e4e8eacbd7c4c248deeca0ec49d38da",
+      "rounds": 1,
+      "type": "eq"
+    },
     {  "id": "issue2177-eq",
       "file": "pdfs/issue2177.pdf",
       "md5": "48a808278bf31de8414c4e03ecd0900a",