BUG#49902 - SELECT returns incorrect results

Queries optimized with GROUP_MIN_MAX didn't cleanup KEYREAD
optimization properly. As a result subsequent queries may
return incomplete rows (fields are initialized to default
values).

mysql-test/r/group_min_max.result:
  A test case for BUG#49902.
mysql-test/t/group_min_max.test:
  A test case for BUG#49902.
sql/opt_range.cc:
  Refactor of KEYREAD optimization switch so that KEYREAD
  handler state is in sync with st_table::key_read flag.
  
  All SQL code is supposed to switch KEYREAD optimization
  via st_table::set_keyread().
sql/opt_sum.cc:
  Refactor of KEYREAD optimization switch so that KEYREAD
  handler state is in sync with st_table::key_read flag.
  
  All SQL code is supposed to switch KEYREAD optimization
  via st_table::set_keyread().
sql/sql_select.cc:
  Refactor of KEYREAD optimization switch so that KEYREAD
  handler state is in sync with st_table::key_read flag.
  
  All SQL code is supposed to switch KEYREAD optimization
  via st_table::set_keyread().
sql/sql_update.cc:
  Refactor of KEYREAD optimization switch so that KEYREAD
  handler state is in sync with st_table::key_read flag.
  
  All SQL code is supposed to switch KEYREAD optimization
  via st_table::set_keyread().
sql/table.cc:
  Refactor of KEYREAD optimization switch so that KEYREAD
  handler state is in sync with st_table::key_read flag.
  
  All SQL code is supposed to switch KEYREAD optimization
  via st_table::set_keyread().
sql/table.h:
  Refactor of KEYREAD optimization switch so that KEYREAD
  handler state is in sync with st_table::key_read flag.
  
  All SQL code is supposed to switch KEYREAD optimization
  via st_table::set_keyread().

1 files changed, 4 insertions, 11 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 94204962345..34757a44c2f 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -1171,11 +1171,7 @@ QUICK_RANGE_SELECT::~QUICK_RANGE_SELECT()
     if (file) 
     {
       range_end();
-      if (head->key_read)
-      {
-        head->key_read= 0;
-        file->extra(HA_EXTRA_NO_KEYREAD);
-      }
+      head->set_keyread(FALSE);
       if (free_file)
       {
         DBUG_PRINT("info", ("Freeing separate handler 0x%lx (free: %d)", (long) file,
@@ -1377,10 +1373,7 @@ end:
   head->file= file;
   /* We don't have to set 'head->keyread' here as the 'file' is unique */
   if (!head->no_keyread)
-  {
-    head->key_read= 1;
     head->mark_columns_used_by_index(index);
-  }
   head->prepare_for_position();
   head->file= org_file;
   bitmap_copy(&column_bitmap, head->read_set);
@@ -8165,7 +8158,7 @@ int QUICK_INDEX_MERGE_SELECT::read_keys_and_merge()
   DBUG_ENTER("QUICK_INDEX_MERGE_SELECT::read_keys_and_merge");
 
   /* We're going to just read rowids. */
-  file->extra(HA_EXTRA_KEYREAD);
+  head->set_keyread(TRUE);
   head->prepare_for_position();
 
   cur_quick_it.rewind();
@@ -8241,7 +8234,7 @@ int QUICK_INDEX_MERGE_SELECT::read_keys_and_merge()
   delete unique;
   doing_pk_scan= FALSE;
   /* index_merge currently doesn't support "using index" at all */
-  file->extra(HA_EXTRA_NO_KEYREAD);
+  head->set_keyread(FALSE);
   init_read_record(&read_record, thd, head, (SQL_SELECT*) 0, 1 , 1, TRUE);
   DBUG_RETURN(result);
 }
@@ -10628,7 +10621,7 @@ int QUICK_GROUP_MIN_MAX_SELECT::reset(void)
   int result;
   DBUG_ENTER("QUICK_GROUP_MIN_MAX_SELECT::reset");
 
-  file->extra(HA_EXTRA_KEYREAD); /* We need only the key attributes */
+  head->set_keyread(TRUE); /* We need only the key attributes */
   if ((result= file->ha_index_init(index,1)))
     DBUG_RETURN(result);
   if (quick_prefix_select && quick_prefix_select->reset())