MDEV-14563: Wrong query plan for query with no PK

TABLE_SHARE::init_from_binary_frm_image() calls handler_file->index_flags()
before it has set TABLE_SHARE::primary_key (it is 0 while it should be
MAX_KEY in my example).
This causes MyRocks to report wrong index flags (it thinks it's a PK while
it is not), which causes invalid query plans later on.

Do the only thing that seems feasible: adjust field->part_of key to have
correct value in ha_rocksdb::open.

storage/rocksdb/ha_rocksdb.cc

@@ -5717,6 +5717,18 @@ int ha_rocksdb::open(const char *const name, int mode, uint test_if_locked) {
         }
       }
     }
+
+    for (uint key= 0; key < table->s->keys; key++) {
+      KEY *const key_info = &table->key_info[key];
+      for (uint kp = 0; kp < key_info->usable_key_parts; kp++) {
+        uint field_index= key_info->key_part[kp].field->field_index;
+        if (m_key_descr_arr[key]->can_unpack(kp)) {
+          table->field[field_index]->part_of_key.set_bit(key);
+        } else {
+          table->field[field_index]->part_of_key.clear_bit(key);
+        }
+      }
+    }
   }
 
   info(HA_STATUS_NO_LOCK | HA_STATUS_VARIABLE | HA_STATUS_CONST);

storage/rocksdb/mysql-test/rocksdb/r/mariadb_port_fixes.result

@@ -30,4 +30,28 @@ a	b	c	d	e
 2	1	1	1	0
 3	1	1	1	0
 DROP TABLE t1;
+#
+# MDEV-14563: Wrong query plan for query with no PK
+#
+CREATE TABLE t1(
+pk int primary key,
+a varchar(10) NOT NULL,   
+e int(11) DEFAULT 0,   
+KEY (a) 
+) ENGINE=ROCKSDB DEFAULT CHARSET=utf8;
+insert into t1 values (1,1,1),(2,2,2);
+explain select a from t1 where a <'zzz';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	a	a	32	NULL	#	Using where
+CREATE TABLE t2(
+pk int,
+a varchar(10) NOT NULL,
+e int(11) DEFAULT 0,   
+KEY (a)
+) ENGINE=ROCKSDB DEFAULT CHARSET=utf8;
+insert into t2 values (1,1,1),(2,2,2);
+explain select a from t2 where a <'zzz';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	range	a	a	32	NULL	#	Using where
+drop table t1,t2;
 set global rocksdb_strict_collation_check=@tmp_rscc;

storage/rocksdb/mysql-test/rocksdb/t/mariadb_port_fixes.test

@@ -27,4 +27,30 @@ select a from t1;
 select * from t1;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-14563: Wrong query plan for query with no PK
+--echo #
+
+CREATE TABLE t1(
+  pk int primary key,
+  a varchar(10) NOT NULL,   
+  e int(11) DEFAULT 0,   
+  KEY (a) 
+) ENGINE=ROCKSDB DEFAULT CHARSET=utf8;
+insert into t1 values (1,1,1),(2,2,2);
+--replace_column 9 #
+explain select a from t1 where a <'zzz';
+
+CREATE TABLE t2(
+  pk int,
+  a varchar(10) NOT NULL,
+  e int(11) DEFAULT 0,   
+  KEY (a)
+) ENGINE=ROCKSDB DEFAULT CHARSET=utf8;
+insert into t2 values (1,1,1),(2,2,2);
+--replace_column 9 #
+explain select a from t2 where a <'zzz';
+
+drop table t1,t2;
+
 set global rocksdb_strict_collation_check=@tmp_rscc;