Fix for bug #14290: wrong CHARACTER_MAXIMUM_LENGTH value for some text fields.

mysql-test/r/information_schema.result

@@ -1025,3 +1025,11 @@ select 1 from (select 1 from test.t1) a;
 1
 use test;
 drop table t1;
+create table t1(a blob, b text charset utf8, c text charset ucs2);
+select data_type, character_octet_length, character_maximum_length 
+from information_schema.columns where table_name='t1';
+data_type	character_octet_length	character_maximum_length
+blob	65535	65535
+text	65535	65535
+text	65535	32767
+drop table t1;

mysql-test/t/information_schema.test

@@ -727,3 +727,12 @@ use information_schema;
 select 1 from (select 1 from test.t1) a;
 use test;
 drop table t1;
+
+#
+# Bug #14290: character_maximum_length for text fields
+#
+
+create table t1(a blob, b text charset utf8, c text charset ucs2);
+select data_type, character_octet_length, character_maximum_length 
+  from information_schema.columns where table_name='t1';
+drop table t1;

sql/sql_show.cc

@@ -2559,8 +2559,9 @@ static int get_schema_column_record(THD *thd, struct st_table_list *tables,
     is_blob= (field->type() == FIELD_TYPE_BLOB);
     if (field->has_charset() || is_blob)
     {
-      longlong char_max_len= is_blob ? (longlong) field->max_length() :
-        (longlong) field->max_length()/field->charset()->mbmaxlen;
+      longlong char_max_len= is_blob ? 
+        (longlong) field->max_length() / field->charset()->mbminlen :
+        (longlong) field->max_length() / field->charset()->mbmaxlen;
       table->field[8]->store(char_max_len, TRUE);
       table->field[8]->set_notnull();
       table->field[9]->store((longlong) field->max_length(), TRUE);