SCRUM

correct sql_alloc, ORDER BY and NULL value in group_concat
add comments
move test msg_arg
add test on NULL


mysql-test/r/func_gconcat.result:
  change work with NULL
mysql-test/t/func_gconcat.test:
  add test on NULL
sql/item_sum.cc:
  correct sql_alloc, ORDER BY and NULL value
  add comments
sql/sql_class.h:
  move test msg_arg

mysql-test/r/func_gconcat.result

@@ -121,7 +121,7 @@ grp	ROUND(group_concat(a separator ""))
 1	1
 2	23
 3	456789
-drop table if exists t1;
+drop table t1;
 create table t1 (grp int, c char(10));
 insert into t1 values (1,NULL);
 insert into t1 values (2,"b");
@@ -132,17 +132,23 @@ insert into t1 values (3,"D");
 insert into t1 values (3,NULL);
 insert into t1 values (3,NULL);
 insert into t1 values (3,"D");
+insert into t1 values (4,"");
+insert into t1 values (5,NULL);
 select grp,group_concat(c order by c) from t1 group by grp;
 grp	group_concat(c order by c)
-1	
-2	 b
-3	   D D E
+1	NULL
+2	b
+3	D D E
+4	
+5	NULL
 set group_concat_max_len = 5;
 select grp,group_concat(c) from t1 group by grp;
 grp	group_concat(c)
-1	
-2	b 
-3	E  D 
+1	NULL
+2	b
+3	E D D
+4	
+5	NULL
 Warnings:
 Warning	1250	1 line(s) was(were) cut by group_concat()
 show warnings;

mysql-test/t/func_gconcat.test

@@ -48,7 +48,7 @@ select grp, ROUND(group_concat(a separator "")) from t1 group by grp;
 
 # Test NULL values
 
-drop table if exists t1;
+drop table t1;
 create table t1 (grp int, c char(10));
 insert into t1 values (1,NULL);
 insert into t1 values (2,"b");
@@ -59,6 +59,8 @@ insert into t1 values (3,"D");
 insert into t1 values (3,NULL);
 insert into t1 values (3,NULL);
 insert into t1 values (3,"D");
+insert into t1 values (4,"");
+insert into t1 values (5,NULL);
 select grp,group_concat(c order by c) from t1 group by grp;
 
 # Test warnings

sql/sql_class.h

@@ -327,12 +327,12 @@ class MYSQL_ERROR: public Sql_alloc
 	      const char *msg_arg)
     :code(code_arg), level(level_arg)
   {
-    set_msg(msg_arg);
+    if (msg_arg)
+      msg=sql_strdup(msg_arg);  
   }
   inline void set_msg(const char *msg_arg)
   {
-    if (msg_arg)
-      msg=sql_strdup(msg_arg);  
+    msg=sql_strdup(msg_arg);  
   }
 };