Fixed BUG#10961: Stored procedures: crash if select * from dual

Have to catch errors from SELECT when opening a cursor.


mysql-test/r/sp.result:
  New test case for BUG#10961.
mysql-test/t/sp.test:
  New test case for BUG#10961.
sql/protocol.h:
  Init data in Protocol_cursor constructor, for error cases.
sql/sp_head.cc:
  Catch "hidden" errors during SELECT when opening a cursor.

mysql-test/r/sp.result

@@ -3109,4 +3109,33 @@ select bug9559()|
 bug9559()
 -3
 drop function bug9559|
+drop procedure if exists bug10961|
+create procedure bug10961()
+begin
+declare v char;
+declare x int;
+declare c cursor for select * from dual;
+declare continue handler for sqlexception select x;
+set x = 1;
+open c;
+set x = 2;
+fetch c into v;
+set x = 3;
+close c;
+end|
+call bug10961()|
+x
+1
+x
+2
+x
+3
+call bug10961()|
+x
+1
+x
+2
+x
+3
+drop procedure bug10961|
 drop table t1,t2;

mysql-test/t/sp.test

@@ -3801,6 +3801,7 @@ call bug5963_2(1)|
 drop procedure bug5963_2|
 drop table t3|
 
+
 #
 # BUG#9559: Functions: Numeric Operations using -ve value gives incorrect
 #           results.
@@ -3820,6 +3821,34 @@ select bug9559()|
 drop function bug9559|
 
 
+#
+# BUG#10961: Stored procedures: crash if select * from dual
+#
+--disable_warnings
+drop procedure if exists bug10961|
+--enable_warnings
+# "select * from dual" results in an error, so the cursor will not open
+create procedure bug10961()
+begin
+  declare v char;
+  declare x int;
+  declare c cursor for select * from dual;
+  declare continue handler for sqlexception select x;
+
+  set x = 1;
+  open c;
+  set x = 2;
+  fetch c into v;
+  set x = 3;
+  close c;
+end|
+
+call bug10961()|
+call bug10961()|
+
+drop procedure bug10961|
+
+
 #
 # BUG#NNNN: New bug synopsis
 #

sql/protocol.h

@@ -159,8 +159,8 @@ public:
   MYSQL_ROWS **prev_record;
   ulong row_count;
 
-  Protocol_cursor() {}
+  Protocol_cursor() :data(NULL) {}
-  Protocol_cursor(THD *thd_arg, MEM_ROOT *ini_alloc) :Protocol_simple(thd_arg), alloc(ini_alloc) {}
+  Protocol_cursor(THD *thd_arg, MEM_ROOT *ini_alloc) :Protocol_simple(thd_arg), alloc(ini_alloc), data(NULL) {}
   bool prepare_for_send(List<Item> *item_list) 
   {
     row_count= 0;

sql/sp_head.cc

@@ -1913,7 +1913,19 @@ sp_instr_copen::execute(THD *thd, uint *nextp)
     else
       res= lex_keeper->reset_lex_and_exec_core(thd, nextp, FALSE, this);
 
-    c->post_open(thd, (lex_keeper ? TRUE : FALSE));
+    /*
+      Work around the fact that errors in selects are not returned properly
+      (but instead converted into a warning), so if a condition handler
+      caught, we have lost the result code.
+     */
+    if (!res)
+    {
+      uint dummy1, dummy2;
+
+      if (thd->spcont->found_handler(&dummy1, &dummy2))
+	res= -1;
+    }
+    c->post_open(thd, (lex_keeper && !res ? TRUE : FALSE));
   }
 
   DBUG_RETURN(res);