Fix for Bug#11247 Stored procedures: Function calls in long loops leak memory

and Bug#12297 SP crashes the server if data inserted inside a lon loop
Third commit attempt. With fixes to the issues, showed up after full rebuild and
tests on other hosts.


mysql-test/r/rpl_sp.result:
  New warnings appeared in result file, as now we always create spcont in a stored routine.
  This is correct behaviour. We swallowed some warnings, as we used thd->spcont to check whether
  we are in the SP though we didn't set spcont in certain cases. This is fixed now.
mysql-test/r/sp.result:
  fixed result file to reflect new tests
mysql-test/t/sp.test:
  Added tests for bugs. Though one of them is disabled, as it fails because of the other bug.
  It should be enabled, when bug 12297 is fixed.
sql/sp_head.cc:
  Per-instruction arena is implemented
sql/sp_rcontext.cc:
   Now we should deal with callers_arena->free_list when we employ reuse mechanism with callers_arena
   switched during sp_eval_func_item
sql/sp_rcontext.h:
  Add new member to sp_rcontext class, in order to handle instructions with assignment
  and/or with nested SP processing properly.

mysql-test/r/rpl_sp.result

@@ -109,6 +109,7 @@ call foo4();
 Got one of the listed errors
 show warnings;
 Level	Code	Message
+Error	1142	INSERT command denied to user 'zedjzlcsjhd'@'localhost' for table 't1'
 Warning	1417	A routine failed and has neither NO SQL nor READS SQL DATA in its declaration and binary logging is enabled; if non-transactional tables were updated, the binary log will miss their changes
 call foo3();
 show warnings;
@@ -117,6 +118,7 @@ call foo4();
 Got one of the listed errors
 show warnings;
 Level	Code	Message
+Error	1142	INSERT command denied to user 'zedjzlcsjhd'@'localhost' for table 't1'
 Warning	1417	A routine failed and has neither NO SQL nor READS SQL DATA in its declaration and binary logging is enabled; if non-transactional tables were updated, the binary log will miss their changes
 alter procedure foo4 sql security invoker;
 call foo4();

mysql-test/r/sp.result

@@ -3085,4 +3085,19 @@ column_name	bug10055(t.column_name)
 id	id
 data	data
 drop function bug10055|
+drop function if exists f_bug11247|
+drop procedure if exists p_bug11247|
+create function f_bug11247(param int)
+returns int
+return param + 1|
+create procedure p_bug11247(lim int)
+begin
+declare v int default 0;
+while v < lim do
+set v= f_bug11247(v);
+end while;
+end|
+call p_bug11247(10)|
+drop function f_bug11247|
+drop procedure p_bug11247|
 drop table t1,t2;

mysql-test/t/sp.test

@@ -3870,6 +3870,65 @@ from information_schema.columns as t
 where t.table_schema = 'test' and t.table_name = 't1'|
 drop function bug10055|
 
+#
+# Bug #12297 "SP crashes the server if data inserted inside a lon loop"
+# The test for memleak bug, so actually there is no way to test it
+# from the suite. The test below could be used to check SP memory
+# consumption by passing large input parameter.
+#
+
+#
+#  Note: the test is currenly disabled because of the
+#  Bug #12637: SP crashes the server if it has update query with user var
+#  & binlog is enabled.
+#
+
+--disable_warnings
+#drop procedure if exists bug12297|
+--enable_warnings
+
+#create procedure bug12297(lim int)
+#begin
+#  set @x = 0;
+#  repeat
+#   insert into t1(id,data)
+#   values('aa', @x);
+#   set @x = @x + 1;
+#  until @x >= lim
+#  end repeat;
+#end|
+
+#call bug12297(10)|
+#drop procedure bug12297|
+
+#
+# Bug #11247 "Stored procedures: Function calls in long loops leak memory"
+# One more memleak bug test. One could use this test to check that the memory
+# isn't leaking by increasing the input value for p_bug11247.
+#
+
+--disable_warnings
+drop function if exists f_bug11247|
+drop procedure if exists p_bug11247|
+--enable_warnings
+
+create function f_bug11247(param int)
+  returns int
+return param + 1|
+
+create procedure p_bug11247(lim int)
+begin
+  declare v int default 0;
+
+  while v < lim do
+    set v= f_bug11247(v);
+  end while;
+end|
+
+call p_bug11247(10)|
+drop function f_bug11247|
+drop procedure p_bug11247|
+
 #
 # BUG#NNNN: New bug synopsis
 #