1 files changed, 20 insertions, 37 deletions

diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 1d33e369af0..fcd9ebdc938 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -891,7 +891,6 @@ int Arg_comparator::set_cmp_func(Item_result_field *owner_arg,
                                         Item **a1, Item **a2,
                                         Item_result type)
 {
-  enum enum_date_cmp_type cmp_type;
   ulonglong const_value= (ulonglong)-1;
   thd= current_thd;
   owner= owner_arg;
@@ -900,7 +899,7 @@ int Arg_comparator::set_cmp_func(Item_result_field *owner_arg,
   b= a2;
   thd= current_thd;
 
-  if ((cmp_type= can_compare_as_dates(*a, *b, &const_value)))
+  if (can_compare_as_dates(*a, *b, &const_value))
   {
     a_type= (*a)->field_type();
     b_type= (*b)->field_type();
@@ -2936,6 +2935,16 @@ void Item_func_case::fix_length_and_dec()
     nagg++;
     if (!(found_types= collect_cmp_types(agg, nagg)))
       return;
+    if (with_sum_func || current_thd->lex->current_select->group_list.elements)
+    {
+      /*
+        See TODO commentary in the setup_copy_fields function:
+        item in a group may be wrapped with an Item_copy_string item.
+        That item has a STRING_RESULT result type, so we need
+        to take this type into account.
+      */
+      found_types |= (1 << item_cmp_type(left_result_type, STRING_RESULT));
+    }
 
     for (i= 0; i <= (uint)DECIMAL_RESULT; i++)
     {
@@ -2972,9 +2981,8 @@ void Item_func_case::fix_length_and_dec()
       agg_num_lengths(args[i + 1]);
     if (else_expr_num != -1) 
       agg_num_lengths(args[else_expr_num]);
-    max_length= my_decimal_precision_to_length_no_truncation(max_length +
-                                                             decimals, decimals,
-                                                             unsigned_flag);
+    max_length= my_decimal_precision_to_length(max_length + decimals, decimals,
+                                               unsigned_flag);
   }
 }
 
@@ -3209,19 +3217,19 @@ int cmp_longlong(void *cmp_arg,
       One of the args is unsigned and is too big to fit into the 
       positive signed range. Report no match.
     */  
-    if ((a->unsigned_flag && ((ulonglong) a->val) > (ulonglong) LONGLONG_MAX) ||
+    if ((a->unsigned_flag && ((ulonglong) a->val) > (ulonglong) LONGLONG_MAX)
+        ||
         (b->unsigned_flag && ((ulonglong) b->val) > (ulonglong) LONGLONG_MAX))
       return a->unsigned_flag ? 1 : -1;
     /*
       Although the signedness differs both args can fit into the signed 
       positive range. Make them signed and compare as usual.
     */  
-    return cmp_longs (a->val, b->val);
+    return cmp_longs(a->val, b->val);
   }
   if (a->unsigned_flag)
-    return cmp_ulongs ((ulonglong) a->val, (ulonglong) b->val);
-  else
-    return cmp_longs (a->val, b->val);
+    return cmp_ulongs((ulonglong) a->val, (ulonglong) b->val);
+  return cmp_longs(a->val, b->val);
 }
 
 static int cmp_double(void *cmp_arg, double *a,double *b)
@@ -5408,33 +5416,7 @@ void Item_equal::merge(Item_equal *item)
 
 void Item_equal::sort(Item_field_cmpfunc cmp, void *arg)
 {
-  bool swap;
-  List_iterator<Item_field> it(fields);
-  do
-  {
-    Item_field *item1= it++;
-    Item_field **ref1= it.ref();
-    Item_field *item2;
-
-    swap= FALSE;
-    while ((item2= it++))
-    {
-      Item_field **ref2= it.ref();
-      if (cmp(item1, item2, arg) < 0)
-      {
-        Item_field *item= *ref1;
-        *ref1= *ref2;
-        *ref2= item;
-        swap= TRUE;
-      }
-      else
-      {
-        item1= item2;
-        ref1= ref2;
-      }
-    }
-    it.rewind();
-  } while (swap);
+  exchange_sort<Item_field>(&fields, cmp, arg);
 }
 
 
@@ -5489,6 +5471,7 @@ void Item_equal::update_used_tables()
   not_null_tables_cache= used_tables_cache= 0;
   if ((const_item_cache= cond_false))
     return;
+  const_item_cache= 1;
   while ((item=li++))
   {
     item->update_used_tables();