Only check if we are out of bounds if the object we are searching for has a known id (0 also means not known)

svn path=/branches/KDE/3.5/kdegraphics/kpdf/; revision=773029

xpdf/xpdf/Lexer.cc

@@ -298,7 +298,7 @@ Object *Lexer::getObj(Object *obj, int objNum) {
 	  n = 0;
 	  
 	  // we are growing see if the document is not malformed and we are growing too much
-	  if (objNum != -1)
+	  if (objNum > 0)
 	  {
 	    int newObjNum = xref->getNumEntry(curStr.streamGetPos());
 	    if (newObjNum != objNum)