ctype_ucs.result, ctype_ucs.test, item.cc:

  #5024 [Ver]: Server crashes with queries on fields with certain charset/collation settings

mysql-test/r/ctype_ucs.result

@@ -464,3 +464,9 @@ HEX(a)
 AAAA
 000AAAAA
 DROP TABLE t1;
+create table t1 (s1 char character set `ucs2` collate `ucs2_czech_ci`);
+insert into t1 values ('0'),('1'),('2'),('a'),('b'),('c');
+select s1 from t1 where s1 > 'a' order by s1;
+s1
+b
+c

mysql-test/t/ctype_ucs.test

@@ -293,3 +293,14 @@ SELECT HEX(a) FROM t1;
 DROP TABLE t1;
 
 -- the same should be also done with enum and set
+
+
+#
+# Bug #5024 Server crashes with queries on fields
+#  with certain charset/collation settings
+#
+
+create table t1 (s1 char character set `ucs2` collate `ucs2_czech_ci`);
+insert into t1 values ('0'),('1'),('2'),('a'),('b'),('c');
+select s1 from t1 where s1 > 'a' order by s1;
+

sql/item.cc

@@ -176,10 +176,15 @@ void Item::set_name(const char *str, uint length, CHARSET_INFO *cs)
     name= (char*) str;
     return;
   }
-  while (length && !my_isgraph(cs,*str))
-  {						// Fix problem with yacc
-    length--;
-    str++;
+  if (cs->ctype)
+  {
+    // This will probably need a better implementation in the future:
+    // a function in CHARSET_INFO structure.
+    while (length && !my_isgraph(cs,*str))
+    {						// Fix problem with yacc
+      length--;
+      str++;
+    }
   }
   if (!my_charset_same(cs, system_charset_info))
   {