diff --git a/mysql-test/r/sp-error.result b/mysql-test/r/sp-error.result
index b81f8ea64c9..c33c378340e 100644
--- a/mysql-test/r/sp-error.result
+++ b/mysql-test/r/sp-error.result
@@ -1579,3 +1579,51 @@ drop function f2;
 drop table t2;
 ERROR 42S02: Unknown table 't2'
 End of 5.1 tests
+drop procedure if exists proc_33983_a;
+drop procedure if exists proc_33983_b;
+drop procedure if exists proc_33983_c;
+drop procedure if exists proc_33983_d;
+create procedure proc_33983_a()
+begin
+label1:
+begin
+label2:
+begin
+select 1;
+end label1;
+end;
+end|
+ERROR 42000: End-label label1 without match
+create procedure proc_33983_b()
+begin
+label1:
+repeat
+label2:
+repeat
+select 1;
+until FALSE end repeat label1;
+until FALSE end repeat;
+end|
+ERROR 42000: End-label label1 without match
+create procedure proc_33983_c()
+begin
+label1:
+while TRUE do
+label2:
+while TRUE do
+select 1;
+end while label1;
+end while;
+end|
+ERROR 42000: End-label label1 without match
+create procedure proc_33983_d()
+begin
+label1:
+loop
+label2:
+loop
+select 1;
+end loop label1;
+end loop;
+end|
+ERROR 42000: End-label label1 without match
diff --git a/mysql-test/r/sp.result b/mysql-test/r/sp.result
index f0318e601d9..50ece83b258 100644
--- a/mysql-test/r/sp.result
+++ b/mysql-test/r/sp.result
@@ -6827,6 +6827,41 @@ SELECT @state, @exception;
 run	NULL
 DROP TABLE t1;
 DROP PROCEDURE bug29770;
+use test;
+drop table if exists t_33618;
+drop procedure if exists proc_33618;
+create table t_33618 (`a` int, unique(`a`), `b` varchar(30)) engine=myisam;
+insert into t_33618 (`a`,`b`) values (1,'1'),(2,'2');
+create procedure proc_33618(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
+leave rep1;
+end if;
+end;
+until last_row=1
+end repeat;
+close cur1;
+end;
+end while;
+end//
+call proc_33618(20);
+drop table t_33618;
+drop procedure proc_33618;
 # ------------------------------------------------------------------
 # -- End of 5.0 tests
 # ------------------------------------------------------------------
diff --git a/mysql-test/t/sp-error.test b/mysql-test/t/sp-error.test
index 606c2a673bc..286722df65c 100644
--- a/mysql-test/t/sp-error.test
+++ b/mysql-test/t/sp-error.test
@@ -2305,6 +2305,69 @@ drop table t2;
 
 --echo End of 5.1 tests
 
+#
+# Bug#33983 (Stored Procedures: wrong end <label> syntax is accepted)
+#
+
+--disable_warnings
+drop procedure if exists proc_33983_a;
+drop procedure if exists proc_33983_b;
+drop procedure if exists proc_33983_c;
+drop procedure if exists proc_33983_d;
+--enable_warnings
+
+delimiter |;
+
+--error ER_SP_LABEL_MISMATCH
+create procedure proc_33983_a()
+begin
+  label1:
+    begin
+      label2:
+      begin
+        select 1;
+      end label1;
+    end;
+end|
+
+--error ER_SP_LABEL_MISMATCH
+create procedure proc_33983_b()
+begin
+  label1:
+    repeat
+      label2:
+      repeat
+        select 1;
+      until FALSE end repeat label1;
+    until FALSE end repeat;
+end|
+
+--error ER_SP_LABEL_MISMATCH
+create procedure proc_33983_c()
+begin
+  label1:
+    while TRUE do
+      label2:
+      while TRUE do
+        select 1;
+      end while label1;
+    end while;
+end|
+
+--error ER_SP_LABEL_MISMATCH
+create procedure proc_33983_d()
+begin
+  label1:
+    loop
+      label2:
+      loop
+        select 1;
+      end loop label1;
+    end loop;
+end|
+
+delimiter ;|
+
 #
 # BUG#NNNN: New bug synopsis
 #
diff --git a/mysql-test/t/sp.test b/mysql-test/t/sp.test
index b40bee4bbf9..6dc2f906d45 100644
--- a/mysql-test/t/sp.test
+++ b/mysql-test/t/sp.test
@@ -7925,6 +7925,58 @@ SELECT @state, @exception;
 DROP TABLE t1;
 DROP PROCEDURE bug29770;
 
+#
+# Bug#33618 Crash in sp_rcontext
+#
+
+use test;
+
+--disable_warnings
+drop table if exists t_33618;
+drop procedure if exists proc_33618;
+--enable_warnings
+
+create table t_33618 (`a` int, unique(`a`), `b` varchar(30)) engine=myisam;
+insert into t_33618 (`a`,`b`) values (1,'1'),(2,'2');
+
+delimiter //;
+
+create procedure proc_33618(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
+            leave rep1;
+          end if;
+        end;
+        until last_row=1
+      end repeat;
+      close cur1;
+    end;
+  end while;
+end//
+
+delimiter ;//
+
+call proc_33618(20);
+
+drop table t_33618;
+drop procedure proc_33618;
+
 ###########################################################################
 
 --echo # ------------------------------------------------------------------
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 9d578589b01..21d465d46f2 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -1284,7 +1284,9 @@ END_OF_INPUT
 %type <NONE> call sp_proc_stmts sp_proc_stmts1 sp_proc_stmt
 %type <NONE> sp_proc_stmt_statement sp_proc_stmt_return
 %type <NONE> sp_proc_stmt_if
-%type <NONE> sp_labeled_control sp_proc_stmt_unlabeled sp_proc_stmt_leave
+%type <NONE> sp_labeled_control sp_proc_stmt_unlabeled
+%type <NONE> sp_labeled_block sp_unlabeled_block
+%type <NONE> sp_proc_stmt_leave
 %type <NONE> sp_proc_stmt_iterate
 %type <NONE> sp_proc_stmt_open sp_proc_stmt_fetch sp_proc_stmt_close
 %type <NONE> case_stmt_specification simple_case_stmt searched_case_stmt
@@ -1945,6 +1947,8 @@ ev_sql_stmt_inner:
         | sp_proc_stmt_return
         | sp_proc_stmt_if
         | case_stmt_specification
+        | sp_labeled_block
+        | sp_unlabeled_block
         | sp_labeled_control
         | sp_proc_stmt_unlabeled
         | sp_proc_stmt_leave
@@ -2519,6 +2523,8 @@ sp_proc_stmt:
         | sp_proc_stmt_return
         | sp_proc_stmt_if
         | case_stmt_specification
+        | sp_labeled_block
+        | sp_unlabeled_block
         | sp_labeled_control
         | sp_proc_stmt_unlabeled
         | sp_proc_stmt_leave
@@ -2645,14 +2651,35 @@ sp_proc_stmt_leave:
               sp_instr_jump *i;
               uint ip= sp->instructions();
               uint n;
+              /*
+                When jumping to a BEGIN-END block end, the target jump
+                points to the block hpop/cpop cleanup instructions,
+                so we should exclude the block context here.
+                When jumping to something else (i.e., SP_LAB_ITER),
+                there are no hpop/cpop at the jump destination,
+                so we should include the block context here for cleanup.
+              */
+              bool exclusive= (lab->type == SP_LAB_BEGIN);
 
-              n= ctx->diff_handlers(lab->ctx, TRUE);  /* Exclusive the dest. */
+              n= ctx->diff_handlers(lab->ctx, exclusive);
               if (n)
-                sp->add_instr(new sp_instr_hpop(ip++, ctx, n));
-              n= ctx->diff_cursors(lab->ctx, TRUE);  /* Exclusive the dest. */
+              {
+                sp_instr_hpop *hpop= new sp_instr_hpop(ip++, ctx, n);
+                if (hpop == NULL)
+                  MYSQL_YYABORT;
+                sp->add_instr(hpop);
+              }
+              n= ctx->diff_cursors(lab->ctx, exclusive);
               if (n)
-                sp->add_instr(new sp_instr_cpop(ip++, ctx, n));
+              {
+                sp_instr_cpop *cpop= new sp_instr_cpop(ip++, ctx, n);
+                if (cpop == NULL)
+                  MYSQL_YYABORT;
+                sp->add_instr(cpop);
+              }
               i= new sp_instr_jump(ip, ctx);
+              if (i == NULL)
+                MYSQL_YYABORT;
               sp->push_backpatch(i, lab);  /* Jumping forward */
               sp->add_instr(i);
             }
@@ -2680,10 +2707,20 @@ sp_proc_stmt_iterate:
 
               n= ctx->diff_handlers(lab->ctx, FALSE);  /* Inclusive the dest. */
               if (n)
-                sp->add_instr(new sp_instr_hpop(ip++, ctx, n));
+              {
+                sp_instr_hpop *hpop= new sp_instr_hpop(ip++, ctx, n);
+                if (hpop == NULL)
+                  MYSQL_YYABORT;
+                sp->add_instr(hpop);
+              }
               n= ctx->diff_cursors(lab->ctx, FALSE);  /* Inclusive the dest. */
               if (n)
-                sp->add_instr(new sp_instr_cpop(ip++, ctx, n));
+              {
+                sp_instr_cpop *cpop= new sp_instr_cpop(ip++, ctx, n);
+                if (cpop == NULL)
+                  MYSQL_YYABORT;
+                sp->add_instr(cpop);
+              }
               i= new sp_instr_jump(ip, ctx, lab->ip); /* Jump back */
               sp->add_instr(i);
             }
@@ -2967,19 +3004,17 @@ sp_labeled_control:
           sp_unlabeled_control sp_opt_label
           {
             LEX *lex= Lex;
+            sp_label_t *lab= lex->spcont->pop_label();
 
             if ($5.str)
             {
-              sp_label_t *lab= lex->spcont->find_label($5.str);
-
-              if (!lab ||
-                  my_strcasecmp(system_charset_info, $5.str, lab->name) != 0)
+              if (my_strcasecmp(system_charset_info, $5.str, lab->name) != 0)
               {
                 my_error(ER_SP_LABEL_MISMATCH, MYF(0), $5.str);
                 MYSQL_YYABORT;
               }
             }
-            lex->sphead->backpatch(lex->spcont->pop_label());
+            lex->sphead->backpatch(lab);
           }
         ;
 
@@ -2988,15 +3023,59 @@ sp_opt_label:
         | label_ident   { $$= $1; }
         ;
 
-sp_unlabeled_control:
+sp_labeled_block:
+          label_ident ':'
+          {
+            LEX *lex= Lex;
+            sp_pcontext *ctx= lex->spcont;
+            sp_label_t *lab= ctx->find_label($1.str);
+
+            if (lab)
+            {
+              my_error(ER_SP_LABEL_REDEFINE, MYF(0), $1.str);
+              MYSQL_YYABORT;
+            }
+
+            lab= lex->spcont->push_label($1.str,
+                                         lex->sphead->instructions());
+            lab->type= SP_LAB_BEGIN;
+          }
+          sp_block_content sp_opt_label
+          {
+            LEX *lex= Lex;
+            sp_label_t *lab= lex->spcont->pop_label();
+
+            if ($5.str)
+            {
+              if (my_strcasecmp(system_charset_info, $5.str, lab->name) != 0)
+              {
+                my_error(ER_SP_LABEL_MISMATCH, MYF(0), $5.str);
+                MYSQL_YYABORT;
+              }
+            }
+          }
+        ;
+
+sp_unlabeled_block:
+          { /* Unlabeled blocks get a secret label. */
+            LEX *lex= Lex;
+            uint ip= lex->sphead->instructions();
+            sp_label_t *lab= lex->spcont->push_label((char *)"", ip);
+            lab->type= SP_LAB_BEGIN;
+          }
+          sp_block_content
+          {
+            LEX *lex= Lex;
+            lex->spcont->pop_label();
+          }
+        ;
+
+sp_block_content:
           BEGIN_SYM
           { /* QQ This is just a dummy for grouping declarations and statements
               together. No [[NOT] ATOMIC] yet, and we need to figure out how
               make it coexist with the existing BEGIN COMMIT/ROLLBACK. */
             LEX *lex= Lex;
-            sp_label_t *lab= lex->spcont->last_label();
-
-            lab->type= SP_LAB_BEGIN;
             lex->spcont= lex->spcont->push_context(LABEL_DEFAULT_SCOPE);
           }
           sp_decls
@@ -3016,7 +3095,10 @@ sp_unlabeled_control:
                                               $3.curs));
             lex->spcont= ctx->pop_context();
           }
-        | LOOP_SYM
+        ;
+
+sp_unlabeled_control:
+          LOOP_SYM
           sp_proc_stmts1 END LOOP_SYM
           {
             LEX *lex= Lex;