Allow skipping of errors when reading broken/corrupt ToUnicode data (issue 11549)

This will allow font loading/parsing to continue, rather than immediately failing, when broken/corrupt CMap data is encountered.

src/core/cmap.js

@@ -996,7 +996,7 @@ var CMapFactory = (function CMapFactoryClosure() {
   }
 
   return {
-    create(params) {
+    async create(params) {
       var encoding = params.encoding;
       var fetchBuiltInCMap = params.fetchBuiltInCMap;
       var useCMap = params.useCMap;
@@ -1015,7 +1015,7 @@ var CMapFactory = (function CMapFactoryClosure() {
           return parsedCMap;
         });
       }
-      return Promise.reject(new Error("Encoding required."));
+      throw new Error("Encoding required.");
     },
   };
 })();

src/core/evaluator.js

@@ -2612,14 +2612,15 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
           encoding: cmapObj,
           fetchBuiltInCMap: this.fetchBuiltInCMap,
           useCMap: null,
-        }).then(function(cmap) {
+        }).then(
+          function(cmap) {
             if (cmap instanceof IdentityCMap) {
               return new IdentityToUnicodeMap(0, 0xffff);
             }
             var map = new Array(cmap.length);
             // Convert UTF-16BE
-          // NOTE: cmap can be a sparse array, so use forEach instead of for(;;)
+            // NOTE: cmap can be a sparse array, so use forEach instead of
-          // to iterate over all keys.
+            // `for(;;)` to iterate over all keys.
             cmap.forEach(function(charCode, token) {
               var str = [];
               for (var k = 0; k < token.length; k += 2) {
@@ -2636,7 +2637,23 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
               map[charCode] = String.fromCodePoint.apply(String, str);
             });
             return new ToUnicodeMap(map);
+          },
+          reason => {
+            if (reason instanceof AbortException) {
+              return null;
+            }
+            if (this.options.ignoreErrors) {
+              // Error in the ToUnicode data -- sending unsupported feature
+              // notification and allow font parsing to continue.
+              this.handler.send("UnsupportedFeature", {
+                featureId: UNSUPPORTED_FEATURES.font,
               });
+              warn(`readToUnicode - ignoring ToUnicode data: "${reason}".`);
+              return null;
+            }
+            throw reason;
+          }
+        );
       }
       return Promise.resolve(null);
     },

test/pdfs/.gitignore

@@ -352,6 +352,7 @@
 !issue7878.pdf
 !font_ascent_descent.pdf
 !issue11442_reduced.pdf
+!issue11549_reduced.pdf
 !issue8097_reduced.pdf
 !transparent.pdf
 !xobject-image.pdf

test/test_manifest.json

@@ -60,6 +60,13 @@
        "link": false,
        "type": "eq"
     },
+    {  "id": "issue11549",
+       "file": "pdfs/issue11549_reduced.pdf",
+       "md5": "a1ea636f413e02e10dbdf379ab4a99ae",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "issue1293",
        "file": "pdfs/issue1293r.pdf",
        "md5": "4a098f5051f34fab036f5bbe88f8deef",