bk commit into 5.0 tree (dkatz:1.2490) BUG#27119

[damien]

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ChangeSet@stripped, 2007-05-17 20:45:33-04:00, dkatz@stripped +1 -0
  Bug #27119  	server crash with integer division by zero during filesort on huge result
  
  Fixed a problem and compiler warning on 64bit platforms so that they only allocated
UINT_MAX number of BUFFPEKS.

  sql/filesort.cc@stripped, 2007-05-17 20:45:28-04:00, dkatz@stripped +2
-2
     Fixed a problem and compiler warning on 64bit platforms so that they only allocated
UINT_MAX number of BUFFPEKS.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	dkatz
# Host:	damien-katzs-computer.local
# Root:	/Users/dkatz/50_div_zero

--- 1.119/sql/filesort.cc	2007-05-17 17:54:27 -04:00
+++ 1.120/sql/filesort.cc	2007-05-17 20:45:28 -04:00
@@ -370,7 +370,7 @@ static BUFFPEK *read_buffpek_from_file(I
   ulong length;
   BUFFPEK *tmp;
   DBUG_ENTER("read_buffpek_from_file");
-  if ((ulong)count > ULONG_MAX/sizeof(BUFFPEK))
+  if (count > UINT_MAX/sizeof(BUFFPEK))
     return 0; /* sizeof(BUFFPEK)*count will overflow */
   tmp=(BUFFPEK*) my_malloc(length=sizeof(BUFFPEK)*count, MYF(MY_WME));
   if (tmp)
@@ -604,7 +604,7 @@ write_keys(SORTPARAM *param, register uc
                        MYF(MY_WME)))
     goto err;                                   /* purecov: inspected */
   /* check we won't have more buffpeks than we can possibly keep in memory */
-  if (my_b_tell(buffpek_pointers) + sizeof(BUFFPEK) > (ulonglong)ULONG_MAX)
+  if (my_b_tell(buffpek_pointers) + sizeof(BUFFPEK) > (ulonglong)UINT_MAX)
     goto err;
   buffpek.file_pos= my_b_tell(tempfile);
   if ((ha_rows) count > param->max_rows)