[fixup] Spider: Restored lines accidentally deleted in MDEV-32157

Also restored a change that resulted in off-by-one, as well as
appending the correctly indexed key_hint.

storage/spider/spd_db_conn.cc

@@ -1512,6 +1512,7 @@ int spider_db_append_key_hint(
     if (str->reserve(
           hint_str_len - 2 + SPIDER_SQL_INDEX_USE_LEN +
           SPIDER_SQL_OPEN_PAREN_LEN + SPIDER_SQL_CLOSE_PAREN_LEN))
+      DBUG_RETURN(HA_ERR_OUT_OF_MEM);
     hint_str += 2;
     str->q_append(SPIDER_SQL_INDEX_USE_STR, SPIDER_SQL_INDEX_USE_LEN);
     str->q_append(SPIDER_SQL_OPEN_PAREN_STR, SPIDER_SQL_OPEN_PAREN_LEN);
@@ -1524,10 +1525,11 @@ int spider_db_append_key_hint(
     if (str->reserve(
           hint_str_len - 3 + SPIDER_SQL_INDEX_IGNORE_LEN +
           SPIDER_SQL_OPEN_PAREN_LEN + SPIDER_SQL_CLOSE_PAREN_LEN))
+      DBUG_RETURN(HA_ERR_OUT_OF_MEM);
     hint_str += 3;
     str->q_append(SPIDER_SQL_INDEX_IGNORE_STR, SPIDER_SQL_INDEX_IGNORE_LEN);
     str->q_append(SPIDER_SQL_OPEN_PAREN_STR, SPIDER_SQL_OPEN_PAREN_LEN);
-    str->q_append(hint_str, hint_str_len - 2);
+    str->q_append(hint_str, hint_str_len - 3);
     str->q_append(SPIDER_SQL_CLOSE_PAREN_STR, SPIDER_SQL_CLOSE_PAREN_LEN);
   } else if (str->reserve(hint_str_len + SPIDER_SQL_SPACE_LEN))
     DBUG_RETURN(HA_ERR_OUT_OF_MEM);

storage/spider/spd_db_mysql.cc

@@ -7612,8 +7612,8 @@ int spider_mbase_share::convert_key_hint_str()
       roop_count < (int) table_share->keys; roop_count++, tmp_key_hint++)
     {
       tmp_key_hint->length(0);
-      if (tmp_key_hint->append(spider_share->key_hint->ptr(),
-        spider_share->key_hint->length(), system_charset_info))
+      if (tmp_key_hint->append(spider_share->key_hint[roop_count].ptr(),
+        spider_share->key_hint[roop_count].length(), system_charset_info))
         DBUG_RETURN(HA_ERR_OUT_OF_MEM);
     }
   } else {