Bug #39920: MySQL cannot deal with Leap Second expression in string literal.

                  
Updated MySQL time handling code to react correctly on UTC leap second additions.
MySQL functions that return the OS current time, like e.g. CURDATE(), NOW() etc
will return :59:59 instead of :59:60 or 59:61.
As a result the reader will receive :59:59 for 2 or 3 consecutive seconds 
during the leap second.
This fix will not affect the values returned by UNIX_TIMESTAMP() for leap seconds.
But note that when converting the value returned by UNIX_TIMESTAMP() to broken 
down time the correction of leap seconds will still be applied.
Note that this fix will make a difference *only* if the OS is specially configured
to return leap seconds from the OS time calls or when using a MySQL time zone 
defintion that has leap seconds.
Even after this change date/time literals (or other broken down time 
representations) with leap seconds (ending on :59:60 or 59:61) will still be 
considered illegal and discarded by the server with an error or 
a warning depending on the sql mode.
Added a test case to demonstrate the effect of the fix.

3 files changed, 20 insertions, 0 deletions

diff --git a/mysql-test/r/timezone3.result b/mysql-test/r/timezone3.result
index ec0b6045f93..ceac4a5aefb 100644
--- a/mysql-test/r/timezone3.result
+++ b/mysql-test/r/timezone3.result
@@ -17,6 +17,9 @@ insert into t1 values
 insert into t1 values
 (unix_timestamp('1981-07-01 03:59:59'),'1981-07-01 03:59:59'),
 (unix_timestamp('1981-07-01 04:00:00'),'1981-07-01 04:00:00');
+insert into t1 values
+(unix_timestamp('2009-01-01 02:59:59'),'2009-01-01 02:59:59'),
+(unix_timestamp('2009-01-01 03:00:00'),'2009-01-01 03:00:00');
 select i, from_unixtime(i), c from t1;
 i	from_unixtime(i)	c
 1072904422	2004-01-01 00:00:00	2004-01-01 00:00:00
@@ -31,6 +34,8 @@ i	from_unixtime(i)	c
 1099180821	2004-10-31 02:59:59	2004-10-31 02:59:59
 362793608	1981-07-01 03:59:59	1981-07-01 03:59:59
 362793610	1981-07-01 04:00:00	1981-07-01 04:00:00
+1230768022	2009-01-01 02:59:59	2009-01-01 02:59:59
+1230768024	2009-01-01 03:00:00	2009-01-01 03:00:00
 drop table t1;
 create table t1 (ts timestamp);
 insert into t1 values (19730101235900), (20040101235900);
@@ -39,3 +44,6 @@ ts
 1973-01-01 23:59:00
 2004-01-01 23:59:00
 drop table t1;
+SELECT FROM_UNIXTIME(1230768022), FROM_UNIXTIME(1230768023), FROM_UNIXTIME(1230768024);
+FROM_UNIXTIME(1230768022)	FROM_UNIXTIME(1230768023)	FROM_UNIXTIME(1230768024)
+2009-01-01 02:59:59	2009-01-01 02:59:59	2009-01-01 03:00:00
diff --git a/mysql-test/std_data/Moscow_leap b/mysql-test/std_data/Moscow_leap
index 4994c005595..3e73923cfb3 100644
--- a/mysql-test/std_data/Moscow_leap
+++ b/mysql-test/std_data/Moscow_leap
diff --git a/mysql-test/t/timezone3.test b/mysql-test/t/timezone3.test
index 0aedbafcec4..8a9941f6383 100644
--- a/mysql-test/t/timezone3.test
+++ b/mysql-test/t/timezone3.test
@@ -45,6 +45,10 @@ insert into t1 values
   (unix_timestamp('1981-07-01 03:59:59'),'1981-07-01 03:59:59'),
   (unix_timestamp('1981-07-01 04:00:00'),'1981-07-01 04:00:00');
 
+insert into t1 values
+  (unix_timestamp('2009-01-01 02:59:59'),'2009-01-01 02:59:59'),
+  (unix_timestamp('2009-01-01 03:00:00'),'2009-01-01 03:00:00');
+
 select i, from_unixtime(i), c from t1;
 drop table t1;
 
@@ -58,4 +62,12 @@ insert into t1 values (19730101235900), (20040101235900);
 select * from t1;
 drop table t1;
 
+#
+# Test Bug #39920: MySQL cannot deal with Leap Second expression in string
+# literal
+#
+
+# 2009-01-01 02:59:59, 2009-01-01 02:59:60 and 2009-01-01 03:00:00
+SELECT FROM_UNIXTIME(1230768022), FROM_UNIXTIME(1230768023), FROM_UNIXTIME(1230768024);
+
 # End of 4.1 tests