Merge from mysql-5.1 to mysql-5.5.

No conflicts.

mysql-test/r/auto_increment.result

@@ -497,3 +497,22 @@ SET @@SESSION.AUTO_INCREMENT_INCREMENT=default;
 SET @@SESSION.AUTO_INCREMENT_OFFSET=default;
 DROP TABLE t1;
 End of 5.1 tests
+#
+# Bug#50619 assert in handler::update_auto_increment
+#
+CREATE TABLE t1 (pk INT AUTO_INCREMENT, PRIMARY KEY (pk));
+INSERT INTO t1 VALUES (NULL), (-1), (NULL);
+SELECT * FROM t1;
+pk
+-1
+1
+2
+DROP TABLE t1;
+CREATE TABLE t1 (pk BIGINT UNSIGNED AUTO_INCREMENT, PRIMARY KEY (pk));
+INSERT INTO t1 VALUES (NULL), (18446744073709551615-1), (NULL);
+ERROR HY000: Failed to read auto-increment value from storage engine
+SELECT * FROM t1;
+pk
+1
+18446744073709551614
+DROP TABLE t1;

mysql-test/t/auto_increment.test

@@ -363,3 +363,20 @@ SET @@SESSION.AUTO_INCREMENT_OFFSET=default;
 DROP TABLE t1;
 
 --echo End of 5.1 tests
+
+--echo #
+--echo # Bug#50619 assert in handler::update_auto_increment
+--echo #
+
+CREATE TABLE t1 (pk INT AUTO_INCREMENT, PRIMARY KEY (pk));
+# This triggered the assert
+INSERT INTO t1 VALUES (NULL), (-1), (NULL);
+SELECT * FROM t1;
+DROP TABLE t1;
+
+# Check that that true overflow still gives error
+CREATE TABLE t1 (pk BIGINT UNSIGNED AUTO_INCREMENT, PRIMARY KEY (pk));
+--error ER_AUTOINC_READ_FAILED
+INSERT INTO t1 VALUES (NULL), (18446744073709551615-1), (NULL);
+SELECT * FROM t1;
+DROP TABLE t1;