ndb - bug#20892

  Fix bug in tup buddy allocator, which made it make invalid access to cfreepagelist[16] (which is not defined)

ndb/src/kernel/blocks/dbtup/DbtupPagMan.cpp

@@ -184,7 +184,10 @@ void Dbtup::allocConsPages(Uint32 noOfPagesToAllocate,
 /*       PROPER AMOUNT OF PAGES WERE NOT FOUND. FIND AS MUCH AS     */
 /*       POSSIBLE.                                                  */
 /* ---------------------------------------------------------------- */
-  for (Uint32 j = firstListToCheck; (Uint32)~j; j--) {
+  if (firstListToCheck)
+  {
+    ljam();
+    for (Uint32 j = firstListToCheck - 1; (Uint32)~j; j--) {
       ljam();
       if (cfreepageList[j] != RNIL) {
 	ljam();
@@ -202,6 +205,7 @@ void Dbtup::allocConsPages(Uint32 noOfPagesToAllocate,
 	return;
       }//if
     }//for
+  }
 /* ---------------------------------------------------------------- */
 /*       NO FREE AREA AT ALL EXISTED. RETURN ZERO PAGES             */
 /* ---------------------------------------------------------------- */