Bug#33618 (Crash in sp_rcontext)

Bug 33983 (Stored Procedures: wrong end <label> syntax is accepted)

The server used to crash when REPEAT or another control instruction
was used in conjunction with labels and a LEAVE instruction.

The crash was caused by a missing "pop" of handlers or cursors in the
code representing the stored program. When executing the code in a loop,
this missing "pop" would result in a stack overflow, corrupting memory.

Code generation has been fixed to produce the missing h_pop/c_pop
instructions.

Also, the logic checking that labels at the beginning and the end of a
statement are matched was incorrect, causing Bug 33983.
End labels, when used, must match the label used at the beginning of a block.


mysql-test/r/sp-code.result:
  Bug#33618 (Crash in sp_rcontext)
mysql-test/r/sp-error.result:
  Bug 33983 (Stored Procedures: wrong end <label> syntax is accepted)
mysql-test/r/sp.result:
  Bug#33618 (Crash in sp_rcontext)
mysql-test/t/sp-code.test:
  Bug#33618 (Crash in sp_rcontext)
mysql-test/t/sp-error.test:
  Bug 33983 (Stored Procedures: wrong end <label> syntax is accepted)
mysql-test/t/sp.test:
  Bug#33618 (Crash in sp_rcontext)
sql/sp_head.cc:
  Bug#33618 (Crash in sp_rcontext)
sql/sp_head.h:
  Bug#33618 (Crash in sp_rcontext)
sql/sp_rcontext.cc:
  Bug#33618 (Crash in sp_rcontext)
sql/sp_rcontext.h:
  Bug#33618 (Crash in sp_rcontext)
sql/sql_yacc.yy:
  Bug#33618 (Crash in sp_rcontext)

1 files changed, 109 insertions, 0 deletions

diff --git a/mysql-test/r/sp-code.result b/mysql-test/r/sp-code.result
index 219f3c9b37a..855cabc25d8 100644
--- a/mysql-test/r/sp-code.result
+++ b/mysql-test/r/sp-code.result
@@ -733,4 +733,113 @@ optimizer: keep hreturn
 drop table t1;
 drop procedure proc_26977_broken;
 drop procedure proc_26977_works;
+drop procedure if exists proc_33618_h;
+drop procedure if exists proc_33618_c;
+create procedure proc_33618_h(num int)
+begin
+declare count1 int default '0';
+declare vb varchar(30);
+declare last_row int;
+while(num>=1) do
+set num=num-1;
+begin
+declare cur1 cursor for select `a` from t_33618;
+declare continue handler for not found set last_row = 1;
+set last_row:=0;
+open cur1;
+rep1:
+repeat
+begin
+declare exit handler for 1062 begin end;
+fetch cur1 into vb;
+if (last_row = 1) then
+## should generate a hpop instruction here
+leave rep1;
+end if;
+end;
+until last_row=1
+end repeat;
+close cur1;
+end;
+end while;
+end//
+create procedure proc_33618_c(num int)
+begin
+declare count1 int default '0';
+declare vb varchar(30);
+declare last_row int;
+while(num>=1) do
+set num=num-1;
+begin
+declare cur1 cursor for select `a` from t_33618;
+declare continue handler for not found set last_row = 1;
+set last_row:=0;
+open cur1;
+rep1:
+repeat
+begin
+declare cur2 cursor for select `b` from t_33618;
+fetch cur1 into vb;
+if (last_row = 1) then
+## should generate a cpop instruction here
+leave rep1;
+end if;
+end;
+until last_row=1
+end repeat;
+close cur1;
+end;
+end while;
+end//
+show procedure code proc_33618_h;
+Pos	Instruction
+0	set count1@1 _latin1'0'
+1	set vb@2 NULL
+2	set last_row@3 NULL
+3	jump_if_not 24(24) (num@0 >= 1)
+4	set num@0 (num@0 - 1)
+5	cpush cur1@0
+6	hpush_jump 9 4 CONTINUE
+7	set last_row@3 1
+8	hreturn 4
+9	set last_row@3 0
+10	copen cur1@0
+11	hpush_jump 13 4 EXIT
+12	hreturn 0 17
+13	cfetch cur1@0 vb@2
+14	jump_if_not 17(17) (last_row@3 = 1)
+15	hpop 1
+16	jump 19
+17	hpop 1
+18	jump_if_not 11(19) (last_row@3 = 1)
+19	cclose cur1@0
+20	hpop 1
+21	cpop 1
+22	jump 3
+show procedure code proc_33618_c;
+Pos	Instruction
+0	set count1@1 _latin1'0'
+1	set vb@2 NULL
+2	set last_row@3 NULL
+3	jump_if_not 23(23) (num@0 >= 1)
+4	set num@0 (num@0 - 1)
+5	cpush cur1@0
+6	hpush_jump 9 4 CONTINUE
+7	set last_row@3 1
+8	hreturn 4
+9	set last_row@3 0
+10	copen cur1@0
+11	cpush cur2@1
+12	cfetch cur1@0 vb@2
+13	jump_if_not 16(16) (last_row@3 = 1)
+14	cpop 1
+15	jump 18
+16	cpop 1
+17	jump_if_not 11(18) (last_row@3 = 1)
+18	cclose cur1@0
+19	hpop 1
+20	cpop 1
+21	jump 3
+drop procedure proc_33618_h;
+drop procedure proc_33618_c;
 End of 5.0 tests.