--- poppler-git-3sep12/poppler/JBIG2Stream.cc-	2012-09-03 01:10:00.441035919 +0200
+++ poppler-git-3sep12/poppler/JBIG2Stream.cc	2012-09-03 14:24:25.829038978 +0200
@@ -1817,6 +1817,10 @@
 	    goto syntaxError;
 	  }
 	  refBitmap = bitmaps[symID];
+	  if (!refBitmap) {
+	    error(errSyntaxError, curStr->getPos(), "Invalid ref bitmap for symbol ID {0:d} in JBIG2 symbol dictionary", symID);
+	    goto syntaxError;	    
+	  }
 	  bitmaps[numInputSyms + i] =
 	      readGenericRefinementRegion(symWidth, symHeight,
 					  sdrTemplate, gFalse,