Fixes for offset bug in UNION's and making UNION's obey

SELECT_DEFAULT_LIMIT


Docs/manual.texi:
  Monty  forced me  to do this

Docs/manual.texi

@@ -48762,6 +48762,16 @@ Our TODO section contains what we plan to have in 4.0. @xref{TODO MySQL 4.0}.
 
 @itemize @bullet
 @item
+Fixed bug in UNION's with last offset being transposed to total result set
+@item
+Fixed that DEFAULT_SELECT_LIMIT is always imposed on UNION's result set 
+@item
+Fixed that some SELECT options can appear only in the first SELECT
+@item
+Fixed bug with LIMIT with UNION, where last select is in the braces
+@item
+Fixed that fulltext works fine with UNION's
+@item
 Fixed bug with indexless boolean full-text search.
 @item
 Fixed bug that sometimes appeared when full-text search was used

mysql-test/r/union.result

@@ -177,4 +177,14 @@ a
 11
 12
 13
+(select * from t1 limit 2) union (select * from t2 limit 20,3);
+a
+1
+2
+set SQL_SELECT_LIMIT=2;
+(select * from t1 limit 2) union (select * from t2 limit 3);
+a
+1
+2
+set SQL_SELECT_LIMIT=DEFAULT;
 drop table t1,t2;

mysql-test/t/union.test

@@ -84,4 +84,8 @@ insert into t1 values (1),(2),(3),(4),(5);
 insert into t2 values (11),(12),(13),(14),(15);
 (select * from t1 limit 2) union (select * from t2 limit 3) limit 4;
 (select * from t1 limit 2) union (select * from t2 limit 3);
+(select * from t1 limit 2) union (select * from t2 limit 20,3);
+set SQL_SELECT_LIMIT=2;
+(select * from t1 limit 2) union (select * from t2 limit 3);
+set SQL_SELECT_LIMIT=DEFAULT;
 drop table t1,t2;

sql/sql_union.cc

@@ -186,7 +186,10 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
 	  thd->options&= ~OPTION_FOUND_ROWS;
       }
       else 
-	thd->select_limit= HA_POS_ERROR;		// no limit
+      {
+	thd->offset_limit= 0;
+	thd->select_limit= thd->default_select_limit;
+      }
       if (describe)
 	thd->select_limit= HA_POS_ERROR;		// no limit
       res=mysql_select(thd,&result_table_list,