MDEV-14433: RocksDB may show empty or incorrect output with rocksdb_strict_collation_check=off

Part#1: Set field->part_of_key correctly for PK fields.

storage/rocksdb/ha_rocksdb.cc

@@ -5698,6 +5698,27 @@ int ha_rocksdb::open(const char *const name, int mode, uint test_if_locked) {
 
   setup_field_converters();
 
+  /*
+    MariaDB: adjust field->part_of_key for PK columns. We can only do it here
+    because SE API is just relying on the HA_PRIMARY_KEY_IN_READ_INDEX which
+    does not allow to distinguish between unpack'able and non-unpack'able
+    columns. 
+    Upstream uses handler->init_with_fields() but we don't have that call.
+  */
+  {
+    if (!has_hidden_pk(table)) {
+      KEY *const pk_info = &table->key_info[table->s->primary_key];
+      for (uint kp = 0; kp < pk_info->user_defined_key_parts; kp++) {
+        if (!m_pk_descr->can_unpack(kp)) {
+          //
+          uint field_index= pk_info->key_part[kp].field->field_index;
+          table->field[field_index]->part_of_key.clear_all();
+          table->field[field_index]->part_of_key.set_bit(table->s->primary_key);
+        }
+      }
+    }
+  }
+
   info(HA_STATUS_NO_LOCK | HA_STATUS_VARIABLE | HA_STATUS_CONST);
 
   /*

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

+#
+# MDEV-14433: RocksDB may show empty or incorrect output with rocksdb_strict_collation_check=off
+#
+set global rocksdb_strict_collation_check=off;
+set @tmp_rscc=@@rocksdb_strict_collation_check;
+CREATE TABLE t1(
+a varchar(10) NOT NULL,
+b char(1) DEFAULT 'X',
+c char(2) NOT NULL DEFAULT '??',
+d varchar(10) NOT NULL,
+e int(11) DEFAULT 0,
+PRIMARY KEY (a,d),
+KEY (e)
+) ENGINE=ROCKSDB DEFAULT CHARSET=utf8;
+insert into t1 select 1,1,1,1,0;
+insert into t1 select 2,1,1,1,0;
+insert into t1 select 3,1,1,1,0;
+explain
+select a from t1 force index(e) where e<10000;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	e	e	5	NULL	#	Using index condition
+select a from t1;
+a
+1
+2
+3
+select * from t1;
+a	b	c	d	e
+1	1	1	1	0
+2	1	1	1	0
+3	1	1	1	0
+DROP TABLE t1;
+set global rocksdb_strict_collation_check=@tmp_rscc;

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

+--source include/have_rocksdb.inc
+
+--echo #
+--echo # MDEV-14433: RocksDB may show empty or incorrect output with rocksdb_strict_collation_check=off
+--echo #
+set global rocksdb_strict_collation_check=off;
+set @tmp_rscc=@@rocksdb_strict_collation_check;
+
+CREATE TABLE t1(
+  a varchar(10) NOT NULL,
+  b char(1) DEFAULT 'X',
+  c char(2) NOT NULL DEFAULT '??',
+  d varchar(10) NOT NULL,
+  e int(11) DEFAULT 0,
+  PRIMARY KEY (a,d),
+  KEY (e)
+) ENGINE=ROCKSDB DEFAULT CHARSET=utf8;
+ 
+insert into t1 select 1,1,1,1,0;
+insert into t1 select 2,1,1,1,0;
+insert into t1 select 3,1,1,1,0;
+ 
+--replace_column 9 #
+explain
+select a from t1 force index(e) where e<10000;
+select a from t1;
+select * from t1;
+DROP TABLE t1;
+
+set global rocksdb_strict_collation_check=@tmp_rscc;