Fix for bug #25301: Non-zero dates with year 0000 are invalid

The 0000 year is valid.
The ISO standard for "Representation of dates and times" says:
"Calendar years are numbered in ascending order according to the 
Gregorian calendar by values in the range [0000] to [9999]."

Reverted fix for 21789: DATETIME with 0000-00-00 11:22:33 should be invalid, but is accepted
as it's not a bug.

Fix for 19370: DateTime datatype in MySQL has two bugs in it
will be reverted during 4.1 -> 5.0 merging as it was pushed to the 
5.0 tree.

mysql-test/r/date_formats.result

@@ -181,12 +181,12 @@ date	format	datetime
 2003-01-02 02:11:12.12345AM	%Y-%m-%d %h:%i:%S.%f %p	2003-01-02 02:11:12.123450
 2003-01-02 12:11:12.12345 am	%Y-%m-%d %h:%i:%S.%f%p	2003-01-02 00:11:12.123450
 2003-01-02 11:11:12Pm	%Y-%m-%d %h:%i:%S%p	2003-01-02 23:11:12
-10:20:10	%H:%i:%s	0000-00-00 00:00:00
-10:20:10	%h:%i:%s.%f	0000-00-00 00:00:00
-10:20:10	%T	0000-00-00 00:00:00
-10:20:10AM	%h:%i:%s%p	0000-00-00 00:00:00
-10:20:10AM	%r	0000-00-00 00:00:00
-10:20:10.44AM	%h:%i:%s.%f%p	0000-00-00 00:00:00
+10:20:10	%H:%i:%s	0000-00-00 10:20:10
+10:20:10	%h:%i:%s.%f	0000-00-00 10:20:10
+10:20:10	%T	0000-00-00 10:20:10
+10:20:10AM	%h:%i:%s%p	0000-00-00 10:20:10
+10:20:10AM	%r	0000-00-00 10:20:10
+10:20:10.44AM	%h:%i:%s.%f%p	0000-00-00 10:20:10.440000
 15-01-2001 12:59:58	%d-%m-%Y %H:%i:%S	2001-01-15 12:59:58
 15 September 2001	%d %M %Y	2001-09-15 00:00:00
 15 SEPTEMB 2001	%d %M %Y	2001-09-15 00:00:00
@@ -203,13 +203,6 @@ Tuesday 52 2001	%W %V %X	2002-01-01 00:00:00
 15-01-2001	%d-%m-%Y %H:%i:%S	2001-01-15 00:00:00
 15-01-20	%d-%m-%y	2020-01-15 00:00:00
 15-2001-1	%d-%Y-%c	2001-01-15 00:00:00
-Warnings:
-Warning	1292	Truncated incorrect datetime value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect datetime value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect datetime value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect datetime value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect datetime value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect datetime value: '0000-00-00 10:20:10.440000'
 select date,format,DATE(str_to_date(date, format)) as date2 from t1;
 date	format	date2
 2003-01-02 10:11:12	%Y-%m-%d %H:%i:%S	2003-01-02
@@ -250,12 +243,12 @@ date	format	time
 2003-01-02 02:11:12.12345AM	%Y-%m-%d %h:%i:%S.%f %p	02:11:12.123450
 2003-01-02 12:11:12.12345 am	%Y-%m-%d %h:%i:%S.%f%p	00:11:12.123450
 2003-01-02 11:11:12Pm	%Y-%m-%d %h:%i:%S%p	23:11:12
-10:20:10	%H:%i:%s	NULL
-10:20:10	%h:%i:%s.%f	NULL
-10:20:10	%T	NULL
-10:20:10AM	%h:%i:%s%p	NULL
-10:20:10AM	%r	NULL
-10:20:10.44AM	%h:%i:%s.%f%p	NULL
+10:20:10	%H:%i:%s	10:20:10
+10:20:10	%h:%i:%s.%f	10:20:10
+10:20:10	%T	10:20:10
+10:20:10AM	%h:%i:%s%p	10:20:10
+10:20:10AM	%r	10:20:10
+10:20:10.44AM	%h:%i:%s.%f%p	10:20:10.440000
 15-01-2001 12:59:58	%d-%m-%Y %H:%i:%S	12:59:58
 15 September 2001	%d %M %Y	00:00:00
 15 SEPTEMB 2001	%d %M %Y	00:00:00
@@ -272,13 +265,6 @@ Tuesday 52 2001	%W %V %X	00:00:00
 15-01-2001	%d-%m-%Y %H:%i:%S	00:00:00
 15-01-20	%d-%m-%y	00:00:00
 15-2001-1	%d-%Y-%c	00:00:00
-Warnings:
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10.440000'
 select date,format,concat(TIME(str_to_date(date, format))) as time2 from t1;
 date	format	time2
 2003-01-02 10:11:12	%Y-%m-%d %H:%i:%S	10:11:12
@@ -288,12 +274,12 @@ date	format	time2
 2003-01-02 02:11:12.12345AM	%Y-%m-%d %h:%i:%S.%f %p	02:11:12.123450
 2003-01-02 12:11:12.12345 am	%Y-%m-%d %h:%i:%S.%f%p	00:11:12.123450
 2003-01-02 11:11:12Pm	%Y-%m-%d %h:%i:%S%p	23:11:12
-10:20:10	%H:%i:%s	NULL
-10:20:10	%h:%i:%s.%f	NULL
-10:20:10	%T	NULL
-10:20:10AM	%h:%i:%s%p	NULL
-10:20:10AM	%r	NULL
-10:20:10.44AM	%h:%i:%s.%f%p	NULL
+10:20:10	%H:%i:%s	10:20:10
+10:20:10	%h:%i:%s.%f	10:20:10
+10:20:10	%T	10:20:10
+10:20:10AM	%h:%i:%s%p	10:20:10
+10:20:10AM	%r	10:20:10
+10:20:10.44AM	%h:%i:%s.%f%p	10:20:10.440000
 15-01-2001 12:59:58	%d-%m-%Y %H:%i:%S	12:59:58
 15 September 2001	%d %M %Y	00:00:00
 15 SEPTEMB 2001	%d %M %Y	00:00:00
@@ -310,13 +296,6 @@ Tuesday 52 2001	%W %V %X	00:00:00
 15-01-2001	%d-%m-%Y %H:%i:%S	00:00:00
 15-01-20	%d-%m-%y	00:00:00
 15-2001-1	%d-%Y-%c	00:00:00
-Warnings:
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10'
-Warning	1292	Truncated incorrect time value: '0000-00-00 10:20:10.440000'
 select concat('',str_to_date('8:11:2.123456 03-01-02','%H:%i:%S.%f %y-%m-%d'));
 concat('',str_to_date('8:11:2.123456 03-01-02','%H:%i:%S.%f %y-%m-%d'))
 2003-01-02 08:11:02.123456

sql-common/my_time.c

@@ -350,10 +350,7 @@ str_to_datetime(const char *str, uint length, MYSQL_TIME *l_time,
       l_time->year > 9999 || l_time->month > 12 ||
       l_time->day > 31 || l_time->hour > 23 ||
       l_time->minute > 59 || l_time->second > 59 ||
-      (!(flags & TIME_FUZZY_DATE) &&
-       (l_time->month == 0 || l_time->day == 0)) ||
-      (l_time->year == 0 && l_time->month == 0 && l_time->day == 0 && 
-       (l_time->hour != 0 || l_time->minute != 0 || l_time->second != 0)))
+      (!(flags & TIME_FUZZY_DATE) && (l_time->month == 0 || l_time->day == 0)))
   {
     /* Only give warning for a zero date if there is some garbage after */
     if (!not_zero_date)                         /* If zero date */