MariaRocks port: Remove handler::init_with_fields

- It turns out, ha_rocksdb::table_flags() can return
  HA_PRIMARY_KEY_IN_READ_INDEX for all kinds of tables (as its meaning
  is "if there is a PK, PK columns contribute to the secondary index
  tuple". There is no assumption that a certain PK column can be decoded
  from the secondary index.
  (Should probably be fixed in the upstream, too, but I was unable to
   construct a testcase showing this is necessary).

- Following the above, we can undo the init_with_fields() changes in
  table.cc. MyRocks calls init_with_fields() from ha_rocksdb::open()
  which sets index-only read capabilities properly.

sql/ha_partition.cc

@@ -421,22 +421,6 @@ ha_partition::~ha_partition()
 }
 
 
-bool ha_partition::init_with_fields()
-{
-  /* Pass the call to each partition */
-  for (uint i= 0; i < m_tot_parts; i++)
-  {
-    if (m_file[i]->init_with_fields())
-      return true;
-  }
-  /* Re-read table flags in case init_with_fields caused it to change */
-  cached_table_flags= (m_file[0]->ha_table_flags() &
-                       ~(PARTITION_DISABLED_TABLE_FLAGS)) |
-                      PARTITION_ENABLED_TABLE_FLAGS;
-  return false;
-}
-
-
 /*
   Initialize partition handler object
 

sql/ha_partition.h

@@ -307,8 +307,6 @@ class ha_partition :public handler
                  ha_partition *clone_arg,
                  MEM_ROOT *clone_mem_root_arg);
    ~ha_partition();
-
-   bool init_with_fields();
   /*
     A partition handler has no characteristics in itself. It only inherits
     those from the underlying handlers. Here we set-up those constants to

sql/handler.h

@@ -2777,8 +2777,6 @@ class handler :public Sql_alloc
   {
     cached_table_flags= table_flags();
   }
-
-  virtual bool init_with_fields() { return false; }
   /* ha_ methods: pubilc wrappers for private virtual API */
   
   int ha_open(TABLE *table, const char *name, int mode, uint test_if_locked);

sql/table.cc

@@ -2230,6 +2230,18 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
         if (key == primary_key)
         {
           field->flags|= PRI_KEY_FLAG;
+          /*
+            If this field is part of the primary key and all keys contains
+            the primary key, then we can use any key to find this column
+          */
+          if (ha_option & HA_PRIMARY_KEY_IN_READ_INDEX)
+          {
+            if (field->key_length() == key_part->length &&
+                !(field->flags & BLOB_FLAG))
+              field->part_of_key= share->keys_in_use;
+            if (field->part_of_sortkey.is_set(key))
+              field->part_of_sortkey= share->keys_in_use;
+          }
         }
         if (field->key_length() != key_part->length)
         {
@@ -2289,38 +2301,6 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
           (ha_option & HA_ANY_INDEX_MAY_BE_UNIQUE))
         set_if_bigger(share->max_unique_length,keyinfo->key_length);
     }
-
-    /*
-      The next call is here for MyRocks/MariaRocks:  Now, we have filled in
-      field and key definitions, give the storage engine a chance to adjust
-      its properties.
-
-      MyRocks may (and typically does) adjust HA_PRIMARY_KEY_IN_READ_INDEX
-      flag in this call.
-    */
-    if (handler_file->init_with_fields())
-      goto err;
-
-    if (primary_key < MAX_KEY && (handler_file->ha_table_flags() &
-                                  HA_PRIMARY_KEY_IN_READ_INDEX))
-    {
-      keyinfo= &share->key_info[primary_key];
-      key_part= keyinfo->key_part;
-      for (i=0 ; i < keyinfo->user_defined_key_parts ; key_part++,i++)
-      {
-        Field *field= key_part->field;
-        /*
-          If this field is part of the primary key and all keys contains
-          the primary key, then we can use any key to find this column
-        */
-        if (field->key_length() == key_part->length &&
-            !(field->flags & BLOB_FLAG))
-          field->part_of_key= share->keys_in_use;
-        if (field->part_of_sortkey.is_set(primary_key))
-          field->part_of_sortkey= share->keys_in_use;
-      }
-    }
-
     if (primary_key < MAX_KEY &&
 	(share->keys_in_use.is_set(primary_key)))
     {

storage/rocksdb/ha_rocksdb.h

@@ -640,18 +640,24 @@ class ha_rocksdb: public my_core::handler
       HA_REC_NOT_IN_SEQ
         If we don't set it, filesort crashes, because it assumes rowids are
         1..8 byte numbers
+      HA_PRIMARY_KEY_IN_READ_INDEX
+        This flag is always set, even for tables that:
+        - have no PK
+        - have some (or all) of PK that can't be decoded from the secondary
+          index.
     */
     return HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE |
            HA_REC_NOT_IN_SEQ | HA_CAN_INDEX_BLOBS |
-           (m_pk_can_be_decoded? HA_PRIMARY_KEY_IN_READ_INDEX : 0) |
+           HA_PRIMARY_KEY_IN_READ_INDEX |
            HA_PRIMARY_KEY_REQUIRED_FOR_POSITION |
            HA_NULL_IN_KEY |
            HA_PARTIAL_COLUMN_READ |
            HA_TABLE_SCAN_ON_INDEX;
   }
-//#ifdef MARIAROCKS_NOT_YET
-  bool init_with_fields() override;
-//#endif
+
+private:
+  bool init_with_fields(); /* no 'override' in MariaDB */
+public:
   /** @brief
     This is a bitmap of flags that indicates how the storage engine
     implements indexes. The current index flags are documented in