Merge mysql-5.1 -> mysql-5.5

storage/innobase/row/row0sel.c

@@ -63,7 +63,13 @@ Created 12/19/1997 Heikki Tuuri
 
 /* Number of rows fetched, after which to start prefetching; MySQL interface
 has another parameter */
-#define SEL_PREFETCH_LIMIT	1
+/* The prefetch code in the internal SQL is disabled because it has probably
+never been used and has been found to contain a memory leak and a bug of
+accessing uninitialized memory. Some simple performance tests show that
+disabling it makes no difference in performance. It will be removed, but
+until the removal happens we disable it by setting SEL_PREFETCH_LIMIT to a
+high value. */
+#define SEL_PREFETCH_LIMIT	1000000000
 
 /* When a select has accessed about this many pages, it returns control back
 to que_run_threads: this is to allow canceling runaway queries */