bk commit into 4.1 tree (sergefp:1.2150) BUG#9213

[Sergey Petrunia]

Below is the list of changes that have just been committed into a local
4.1 repository of psergey. When psergey does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet
  1.2150 05/03/30 14:53:49 sergefp@stripped +1 -0
  BUG#9213 - added more comments to fix

  sql/sql_select.cc
    1.392 05/03/30 14:53:47 sergefp@stripped +4 -2
    BUG#9213 - added more comments to fix

# 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:	sergefp
# Host:	newbox.mylan
# Root:	/home/psergey/mysql-4.1-bug9213

--- 1.391/sql/sql_select.cc	2005-03-30 14:35:35 +04:00
+++ 1.392/sql/sql_select.cc	2005-03-30 14:53:47 +04:00
@@ -7185,8 +7185,10 @@
 	{
           /*
             We'll use ref access method on key new_ref_key. In general case 
-            index search tuple for new_ref_key will be different, so we build
-            it from scratch here.
+            the index search tuple for new_ref_key will be different (e.g.
+            when one of the indexes only covers prefix of the field, see
+            BUG#9213 in group_by.test).
+            So we build tab->ref from scratch here.
           */
           KEYUSE *keyuse= tab->keyuse;
           while (keyuse->key != new_ref_key && keyuse->table ==
tab->table)