Bug #55779: select does not work properly in mysql server

            Version "5.1.42 SUSE MySQL RPM"

When a query was using a DATE or DATETIME value formatted
using different formatting than "yyyy-mm-dd HH:MM:SS", a
query with a greater-or-equal '>=' condition matched only
greater values in an indexed TIMESTAMP column.

The problem was introduced by the fix for the bug 46362
and partially solved (for DATE and DATETIME columns only)
by the fix for the bug 47925.

The stored_field_cmp_to_item function has been modified
to take into account TIMESTAMP columns like we do for
DATE and DATETIME columns.

mysql-test/r/type_timestamp.result

@@ -527,3 +527,24 @@ f1	f2-f3
 5	0
 DROP TABLE t1;
 End of 5.0 tests
+#
+# Bug #55779: select does not work properly in mysql server
+#             Version "5.1.42 SUSE MySQL RPM"
+#
+CREATE TABLE t1 (a TIMESTAMP, KEY (a));
+INSERT INTO t1 VALUES ('2000-01-01 00:00:00'), ('2000-01-01 00:00:00'),
+('2000-01-01 00:00:01'), ('2000-01-01 00:00:01');
+SELECT a FROM t1 WHERE a >=  20000101000000;
+a
+2000-01-01 00:00:00
+2000-01-01 00:00:00
+2000-01-01 00:00:01
+2000-01-01 00:00:01
+SELECT a FROM t1 WHERE a >= '20000101000000';
+a
+2000-01-01 00:00:00
+2000-01-01 00:00:00
+2000-01-01 00:00:01
+2000-01-01 00:00:01
+DROP TABLE t1;
+End of 5.1 tests

mysql-test/t/type_timestamp.test

@@ -357,3 +357,20 @@ SELECT f1,f2-f3 FROM t1;
 DROP TABLE t1;
 
 --echo End of 5.0 tests
+
+--echo #
+--echo # Bug #55779: select does not work properly in mysql server
+--echo #             Version "5.1.42 SUSE MySQL RPM"
+--echo #
+
+CREATE TABLE t1 (a TIMESTAMP, KEY (a));
+
+INSERT INTO t1 VALUES ('2000-01-01 00:00:00'), ('2000-01-01 00:00:00'),
+                      ('2000-01-01 00:00:01'), ('2000-01-01 00:00:01');
+
+SELECT a FROM t1 WHERE a >=  20000101000000;
+SELECT a FROM t1 WHERE a >= '20000101000000';
+
+DROP TABLE t1;
+
+--echo End of 5.1 tests

sql/item.cc

@@ -6970,14 +6970,16 @@ int stored_field_cmp_to_item(THD *thd, Field *field, Item *item)
 
     enum_field_types field_type= field->type();
 
-    if (field_type == MYSQL_TYPE_DATE || field_type == MYSQL_TYPE_DATETIME)
+    if (field_type == MYSQL_TYPE_DATE || field_type == MYSQL_TYPE_DATETIME ||
+        field_type == MYSQL_TYPE_TIMESTAMP)
     {
       enum_mysql_timestamp_type type= MYSQL_TIMESTAMP_ERROR;
 
       if (field_type == MYSQL_TYPE_DATE)
         type= MYSQL_TIMESTAMP_DATE;
 
-      if (field_type == MYSQL_TYPE_DATETIME)
+      if (field_type == MYSQL_TYPE_DATETIME ||
+          field_type == MYSQL_TYPE_TIMESTAMP)
         type= MYSQL_TIMESTAMP_DATETIME;
         
       const char *field_name= field->field_name;