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

src/core/jbig2.js

@@ -445,8 +445,19 @@ 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,
+                                      numberOfInstances, 1, //strip size
+                                      symbols.concat(newSymbols),
+                                      symbolCodeLength,
+                                      0, //transposed
+                                      0, //ds offset
+                                      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
@@ -455,6 +466,7 @@ var Jbig2Image = (function Jbig2ImageClosure() {
             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,