Recommit of patch for bug#49028 for 5.1.

Includes both patch from bug#48737 (without test,
which should go to next-mr) and test for
bug#49028.

mysql-test/r/ctype_ucs.result

@@ -116,6 +116,26 @@ select binary 'a  a' > 'a', binary 'a  \0' > 'a', binary 'a\0' > 'a';
 binary 'a  a' > 'a'	binary 'a  \0' > 'a'	binary 'a\0' > 'a'
 1	1	1
 SET CHARACTER SET koi8r;
+create table t1 (a varchar(2) character set ucs2 collate ucs2_bin, key(a));
+insert into t1 values ('A'),('A'),('B'),('C'),('D'),('A\t');
+insert into t1 values ('A\0'),('A\0'),('A\0'),('A\0'),('AZ');
+select hex(a) from t1 where a like 'A_' order by a;
+hex(a)
+00410000
+00410000
+00410000
+00410000
+00410009
+0041005A
+select hex(a) from t1 ignore key(a) where a like 'A_' order by a;
+hex(a)
+00410000
+00410000
+00410000
+00410000
+00410009
+0041005A
+drop table t1;
 CREATE TABLE t1 (word VARCHAR(64) CHARACTER SET ucs2, word2 CHAR(64) CHARACTER SET ucs2);
 INSERT INTO t1 VALUES (_koi8r'',_koi8r''), (X'2004',X'2004');
 SELECT hex(word) FROM t1 ORDER BY word;

mysql-test/t/ctype_ucs.test

@@ -14,6 +14,16 @@ SET character_set_connection=ucs2;
 
 SET CHARACTER SET koi8r;
 
+#
+# BUG#49028, error in LIKE with ucs2
+#
+create table t1 (a varchar(2) character set ucs2 collate ucs2_bin, key(a));
+insert into t1 values ('A'),('A'),('B'),('C'),('D'),('A\t');
+insert into t1 values ('A\0'),('A\0'),('A\0'),('A\0'),('AZ');
+select hex(a) from t1 where a like 'A_' order by a;
+select hex(a) from t1 ignore key(a) where a like 'A_' order by a;
+drop table t1;
+
 #
 # Check that 0x20 is only trimmed when it is 
 # a part of real SPACE character, not just a part

strings/ctype-ucs2.c

@@ -1602,16 +1602,6 @@ fill_max_and_min:
     *min_str++= *max_str++ = ptr[1];
   }
 
-  /* Temporary fix for handling w_one at end of string (key compression) */
-  {
-    char *tmp;
-    for (tmp= min_str ; tmp-1 > min_org && tmp[-1] == '\0' && tmp[-2]=='\0';)
-    {
-      *--tmp=' ';
-      *--tmp='\0';
-    }
-  }
-  
   *min_length= *max_length = (size_t) (min_str - min_org);
   while (min_str + 1 < min_end)
   {