Fixed error found during review of new pushed code

client/mysql.cc:
  Don't use c_ptr() for cgets() and ensure buffer is not overwritten
mysql-test/r/cast.result:
  More test for CAST(0x.... as signed)
sql/opt_sum.cc:
  Fix bugs found during review
  - Changed code to be able to remove one if
  - Ensure that count == 0 only if is_exact_count == TRUE
sql/sql_delete.cc:
  Ensure 'allow_sum_func' is reset before call to setup_conds
sql/sql_lex.cc:
  allow_sum_func doesn't have to be reset for each query
  (It's to be reset in setup_fields() or before call to setup_conds()
sql/sql_load.cc:
  Move set of auto_increment_field_not_null so that it's not set if field value is NULL
sql/sql_prepare.cc:
  allow_sum_func doesn't have to be reset for each query
  (It's to be reset in setup_fields() or before call to setup_conds()
sql/sql_update.cc:
  Ensure 'allow_sum_func' is reset before call to setup_conds

1 files changed, 7 insertions, 7 deletions

diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index 3ac72e5a6f9..cfb5b3695a3 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -108,7 +108,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
           WHERE t2.field IS NULL;
       */
       if (tl->table->map & where_tables)
-        const_result= 0;
+        return 0;
     }
     else
       used_tables|= tl->table->map;
@@ -119,7 +119,10 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
       may be used as the real count.
     */
     if (tl->table->file->table_flags() & HA_NOT_EXACT_COUNT)
+    {
       is_exact_count= FALSE;
+      count= 1;                                 // ensure count != 0
+    }
     else
     {
       tl->table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
@@ -127,9 +130,6 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
     }
   }
 
-  if (!const_result)
-    return 0;
-
   /*
     Iterate through all items in the SELECT clause and replace
     COUNT(), MIN() and MAX() with constants (if possible).
@@ -150,8 +150,8 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
         if (!conds && !((Item_sum_count*) item)->args[0]->maybe_null &&
             !outer_tables && is_exact_count)
         {
-            ((Item_sum_count*) item)->make_const(count);
-            recalc_const_item= 1;
+          ((Item_sum_count*) item)->make_const(count);
+          recalc_const_item= 1;
         }
         else
           const_result= 0;
@@ -234,7 +234,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
         }
         if (!count)
         {
-          /* If count != 1, then we know that is_exact_count == TRUE. */
+          /* If count == 0, then we know that is_exact_count == TRUE. */
           ((Item_sum_min*) item_sum)->clear(); /* Set to NULL. */
         }
         else