Auto-merge from mysql-trunk-bugfixing.

******
This patch fixes the following bugs:
  - Bug#5889: Exit handler for a warning doesn't hide the warning in
    trigger
  - Bug#9857: Stored procedures: handler for sqlwarning ignored
  - Bug#23032: Handlers declared in a SP do not handle warnings generated
    in sub-SP
  - Bug#36185: Incorrect precedence for warning and exception handlers

The problem was in the way warnings/errors during stored routine execution
were handled. Prior to this patch the logic was as follows:

  - when a warning/an error happens: if we're executing a stored routine,
    and there is a handler for that warning/error, remember the handler,
    ignore the warning/error and continue execution.

  - after a stored routine instruction is executed: check for a remembered
    handler and activate one (if any).

This logic caused several problems:

  - if one instruction generates several warnings (errors) it's impossible
    to choose the right handler -- a handler for the first generated
    condition was chosen and remembered for activation.

  - mess with handling conditions in scopes different from the current one.

  - not putting generated warnings/errors into Warning Info (Diagnostic
    Area) is against The Standard.

The patch changes the logic as follows:

  - Diagnostic Area is cleared on the beginning of each statement that
    either is able to generate warnings, or is able to work with tables.

  - at the end of a stored routine instruction, Diagnostic Area is left
    intact.

  - Diagnostic Area is checked after each stored routine instruction. If
    an instruction generates several condition, it's now possible to take a
    look at all of them and determine an appropriate handler.

mysql-test/suite/funcs_1/r/innodb_storedproc_02.result

@@ -347,6 +347,8 @@ CALL h1();
 -7-	1	1	1	1	1	1
 END	x1	x2	x3	x4	x5	x6
 END	1	1	1	1	1	1
+Warnings:
+Error	1062	Duplicate entry 'a' for key 'w'
 DROP TABLE IF EXISTS tnull;
 DROP PROCEDURE IF EXISTS sp1;
 CREATE TABLE tnull(f1 int);
@@ -445,6 +447,8 @@ END//
 CALL h2();
 x1	x2	x3	x4	x5	x6
 1	1	1	1	1	1
+Warnings:
+Error	1062	Duplicate entry 'a' for key 'w'
 SELECT * FROM res_t1;
 w	x
 a	b
@@ -550,6 +554,8 @@ exit handler 2
 exit handler 2
 exit handler 1
 exit handler 1
+Warnings:
+Error	1146	Table 'db_storedproc.tqq' doesn't exist
 create table res_t1(w char unique, x char);
 insert into res_t1 values ('a', 'b');
 CREATE PROCEDURE h1 ()
@@ -580,6 +586,8 @@ END//
 CALL h1();
 x1	x2	x3	x4	x5	x6
 1	1	1	1	1	1
+Warnings:
+Error	1062	Duplicate entry 'a' for key 'w'
 This will fail, SQLSTATE 00000 is not allowed
 CREATE PROCEDURE sp1()
 begin1_label:BEGIN
@@ -623,6 +631,8 @@ CALL sp2();
 NULL
 @x2	@x
 1	2
+Warnings:
+Error	1318	Incorrect number of arguments for PROCEDURE db_storedproc.sp1; expected 2, got 1
 DROP PROCEDURE sp1;
 DROP PROCEDURE sp2;
 
@@ -654,6 +664,8 @@ ERROR 42000: Incorrect number of arguments for PROCEDURE db_storedproc.sp1; expe
 CALL sp2();
 -1-	@x2	@x
 -1-	0	1
+Warnings:
+Error	1318	Incorrect number of arguments for PROCEDURE db_storedproc.sp1; expected 2, got 1
 SELECT '-3-', @x2, @x;
 -3-	@x2	@x
 -3-	1	1
@@ -696,6 +708,8 @@ CALL sp2();
 -2-	1	20
 -4-	@x2	@x
 -4-	11	22
+Warnings:
+Error	1318	Incorrect number of arguments for PROCEDURE db_storedproc.sp1; expected 2, got 1
 DROP PROCEDURE sp1;
 DROP PROCEDURE sp2;
 
@@ -762,21 +776,33 @@ SELECT @done, @x;
 0	1
 INSERT INTO temp VALUES('1', NULL);
 CALL sp1();
+Warnings:
+Warning	1265	Data truncated for column 'f1' at row 1
+Warning	1265	Data truncated for column 'f2' at row 1
 SELECT @done, @x;
 @done	@x
 1	1
 INSERT INTO temp VALUES('2', NULL);
 CALL sp2();
+Warnings:
+Warning	1265	Data truncated for column 'f1' at row 1
+Warning	1265	Data truncated for column 'f2' at row 1
 SELECT @done, @x;
 @done	@x
 1	1
 INSERT INTO temp VALUES('3', NULL);
 CALL sp3();
+Warnings:
+Warning	1265	Data truncated for column 'f1' at row 1
+Warning	1265	Data truncated for column 'f2' at row 1
 SELECT @done, @x;
 @done	@x
 1	0
 INSERT INTO temp VALUES('4', NULL);
 CALL sp4();
+Warnings:
+Warning	1265	Data truncated for column 'f1' at row 1
+Warning	1265	Data truncated for column 'f2' at row 1
 SELECT @done, @x;
 @done	@x
 1	0
@@ -885,18 +911,26 @@ SELECT @done, @x;
 @done	@x
 0	1
 CALL sp1();
+Warnings:
+Error	1329	No data - zero rows fetched, selected, or processed
 SELECT @done, @x;
 @done	@x
 1	2
 CALL sp2();
+Warnings:
+Error	1329	No data - zero rows fetched, selected, or processed
 SELECT @done, @x;
 @done	@x
 1	2
 CALL sp3();
+Warnings:
+Error	1329	No data - zero rows fetched, selected, or processed
 SELECT @done, @x;
 @done	@x
 1	1
 CALL sp4();
+Warnings:
+Error	1329	No data - zero rows fetched, selected, or processed
 SELECT @done, @x;
 @done	@x
 1	1
@@ -1031,6 +1065,8 @@ SQLSTATE
 21000
 SQLSTATE
 24000
+Warnings:
+Error	1326	Cursor is not open
 SELECT '-1-', @x;
 -1-	@x
 -1-	6
@@ -1041,18 +1077,24 @@ SQLSTATE
 SQLEXCEPTION
 SQLSTATE
 24000
+Warnings:
+Error	1326	Cursor is not open
 SELECT '-2-', @x;
 -2-	@x
 -2-	6
 CALL sp3();
 SQLSTATE
 20000
+Warnings:
+Error	1339	Case not found for CASE statement
 SELECT '-3-', @x;
 -3-	@x
 -3-	1
 CALL sp4();
 SQLSTATE
 SQLEXCEPTION
+Warnings:
+Error	1339	Case not found for CASE statement
 SELECT '-4-', @x;
 -4-	@x
 -4-	1
@@ -1335,6 +1377,8 @@ CLOSE cur1;
 CLOSE cur2;
 END//
 CALL sp_outer();
+Warnings:
+Error	1329	No data - zero rows fetched, selected, or processed
 SELECT * FROM temp1;
 f0	cnt	f1	f2	f3	f4
 _sp_out_	1	a`	a`	1000-01-01	-5000