Fix for #3181: jbig2 encoding for number of instances greater than 1

src/core/jbig2.js

@@ -445,16 +445,28 @@ var Jbig2Image = (function Jbig2ImageClosure() {
           // 6.5.8.2 Refinement/aggregate-coded symbol bitmap
           var numberOfInstances = decodeInteger(contextCache, 'IAAI', decoder);
           if (numberOfInstances > 1) {
-            error('JBIG2 error: number of instances > 1 is not supported');
+            bitmap = decodeTextRegion(huffman, refinement,
-          }
+                                      currentWidth, currentHeight, 0,
-          var symbolId = decodeIAID(contextCache, decoder, symbolCodeLength);
+                                      numberOfInstances, 1, //strip size
-          var rdx = decodeInteger(contextCache, 'IARDX', decoder); // 6.4.11.3
+                                      symbols.concat(newSymbols),
-          var rdy = decodeInteger(contextCache, 'IARDY', decoder); // 6.4.11.4
+                                      symbolCodeLength,
-          var symbol = (symbolId < symbols.length ? symbols[symbolId] :
+                                      0, //transposed
-                        newSymbols[symbolId - symbols.length]);
+                                      0, //ds offset
-          bitmap = decodeRefinement(currentWidth, currentHeight,
+                                      1, //top left 7.4.3.1.1
+                                      0, //OR operator
+                                      huffmanTables,
+                                      refinementTemplateIndex, refinementAt,
+                                      decodingContext);
+          } else {
+            var symbolId = decodeIAID(contextCache, decoder, symbolCodeLength);
+            var rdx = decodeInteger(contextCache, 'IARDX', decoder); // 6.4.11.3
+            var rdy = decodeInteger(contextCache, 'IARDY', decoder); // 6.4.11.4
+            var symbol = (symbolId < symbols.length ? symbols[symbolId] :
+                          newSymbols[symbolId - symbols.length]);
+            bitmap = decodeRefinement(currentWidth, currentHeight,
             refinementTemplateIndex, symbol, rdx, rdy, false, refinementAt,
             decodingContext);
+          }
         } else {
           // 6.5.8.1 Direct-coded symbol bitmap
           bitmap = decodeBitmap(false, currentWidth, currentHeight,