Bug#38909 CREATE_OPTIONS in information_schema produces wrong results

table->partition_info is unitialized when we open frm file only.
The fix is check share->partition_info_len which is set on
frm opening stage.


mysql-test/r/information_schema_part.result:
  test result
mysql-test/t/information_schema_part.test:
  test case
sql/sql_show.cc:
  table->partition_info is unitialized when we open frm file only.
  The fix is check share->partition_info_len which is set on
  frm opening stage.

mysql-test/r/information_schema_part.result

@@ -145,3 +145,9 @@ table_schema = "test" AND table_name = "t1";
 PARTITION_DESCRIPTION
 10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53
 drop table t1;
+drop table if exists t1;
+create table t1 (f1 int key) partition by key(f1) partitions 2;
+select create_options from information_schema.tables where table_schema="test";
+create_options
+partitioned
+drop table t1;

mysql-test/t/information_schema_part.test

@@ -121,3 +121,13 @@ SHOW CREATE TABLE t1;
 SELECT PARTITION_DESCRIPTION FROM information_schema.partitions WHERE
 table_schema = "test" AND table_name = "t1";
 drop table t1;
+
+#
+# Bug#38909 CREATE_OPTIONS in information_schema produces wrong results
+#
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+create table t1 (f1 int key) partition by key(f1) partitions 2;
+select create_options from information_schema.tables where table_schema="test";
+drop table t1;

sql/sql_show.cc

@@ -3511,6 +3511,7 @@ static int get_schema_tables_record(THD *thd, TABLE_LIST *tables,
     TABLE_SHARE *share= show_table->s;
     handler *file= show_table->file;
     handlerton *tmp_db_type= share->db_type();
+    bool is_partitioned= FALSE;
     if (share->tmp_table == SYSTEM_TMP_TABLE)
       table->field[3]->store(STRING_WITH_LEN("SYSTEM VIEW"), cs);
     else if (share->tmp_table)
@@ -3527,7 +3528,10 @@ static int get_schema_tables_record(THD *thd, TABLE_LIST *tables,
 #ifdef WITH_PARTITION_STORAGE_ENGINE
     if (share->db_type() == partition_hton &&
         share->partition_info_len)
+    {
       tmp_db_type= share->default_part_db_type;
+      is_partitioned= TRUE;
+    }
 #endif
     tmp_buff= (char *) ha_resolve_storage_engine_name(tmp_db_type);
     table->field[4]->store(tmp_buff, strlen(tmp_buff), cs);
@@ -3572,9 +3576,7 @@ static int get_schema_tables_record(THD *thd, TABLE_LIST *tables,
                    NullS);
     }
 #ifdef WITH_PARTITION_STORAGE_ENGINE
-    if (show_table->s->db_type() == partition_hton && 
-        show_table->part_info != NULL && 
-        show_table->part_info->no_parts > 0)
+    if (is_partitioned)
       ptr= strmov(ptr, " partitioned");
 #endif
     if (share->transactional != HA_CHOICE_UNDEF)