item_cmpfunc.cc:

  Removed changes to the Item_func_between::fix_length_and_dec() made in the fix for bug#16377
query_cache.result:
  Corrected a test case after removing a fix for bug#16377

mysql-test/r/query_cache.result

@@ -907,16 +907,19 @@ COUNT(*)
 0
 Warnings:
 Warning	1292	Truncated incorrect datetime value: '20050327 invalid'
+Warning	1292	Truncated incorrect datetime value: '20050327 invalid'
 SELECT COUNT(*) FROM t1 WHERE date BETWEEN '20050326' AND '20050328 invalid';
 COUNT(*)
 0
 Warnings:
 Warning	1292	Truncated incorrect datetime value: '20050328 invalid'
+Warning	1292	Truncated incorrect datetime value: '20050328 invalid'
 SELECT COUNT(*) FROM t1 WHERE date BETWEEN '20050326' AND '20050327 invalid';
 COUNT(*)
 0
 Warnings:
 Warning	1292	Truncated incorrect datetime value: '20050327 invalid'
+Warning	1292	Truncated incorrect datetime value: '20050327 invalid'
 show status like "Qcache_queries_in_cache";
 Variable_name	Value
 Qcache_queries_in_cache	0

sql/item_cmpfunc.cc

@@ -916,8 +916,30 @@ void Item_func_between::fix_length_and_dec()
   if (!args[0] || !args[1] || !args[2])
     return;
   agg_cmp_type(thd, &cmp_type, args, 3);
-  if (cmp_type == STRING_RESULT)
-      agg_arg_charsets(cmp_collation, args, 3, MY_COLL_CMP_CONV);
+  if (cmp_type == STRING_RESULT &&
+      agg_arg_charsets(cmp_collation, args, 3, MY_COLL_CMP_CONV))
+   return;
+
+  /*
+    Make a special case of compare with date/time and longlong fields.
+    They are compared as integers, so for const item this time-consuming
+    conversion can be done only once, not for every single comparison
+  */
+  if (args[0]->type() == FIELD_ITEM)
+  {
+    Field *field=((Item_field*) args[0])->field;
+    if (field->can_be_compared_as_longlong())
+    {
+      /*
+        The following can't be recoded with || as convert_constant_item
+        changes the argument
+      */
+      if (convert_constant_item(thd, field,&args[1]))
+	cmp_type=INT_RESULT;			// Works for all types.
+      if (convert_constant_item(thd, field,&args[2]))
+	cmp_type=INT_RESULT;			// Works for all types.
+    }
+  }
 }