Bug #30667 ndb table discovery does not work correcly with information schema

- the listed file_names are not necessarily on disk, so we need to discover them if they aren't

mysql-test/t/ndb_restore.test

@@ -180,6 +180,11 @@ drop table t1_c,t2_c,t3_c,t4_c,t5_c,t6_c,t7_c,t8_c,t9_c,t10_c;
 --exec $NDB_TOOLS_DIR/ndb_desc --no-defaults -d test t3_c | grep ForceVarPart
 --exec $NDB_TOOLS_DIR/ndb_desc --no-defaults -d test t2_c | grep ForceVarPart
 
+# Bug #30667
+# ndb table discovery does not work correcly with information schema
+# - prior to bug fix this would yeild no output and a warning
+select * from information_schema.columns where table_name = "t1_c";
+
 # random output order??
 #show tables;
 

sql/ha_ndbcluster.cc

@@ -6955,9 +6955,26 @@ int ndbcluster_find_files(handlerton *hton, THD *thd,
   while ((file_name=it++))
   {
     bool file_on_disk= FALSE;
-    DBUG_PRINT("info", ("%s", file_name));     
+    DBUG_PRINT("info", ("%s", file_name));
     if (hash_search(&ndb_tables, file_name, strlen(file_name)))
     {
+      build_table_filename(name, sizeof(name), db, file_name, reg_ext, 0);
+      if (my_access(name, F_OK))
+      {
+        pthread_mutex_lock(&LOCK_open);
+        DBUG_PRINT("info", ("Table %s listed and need discovery",
+                            file_name));
+        if (ndb_create_table_from_engine(thd, db, file_name))
+        {
+          pthread_mutex_unlock(&LOCK_open);
+          push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                              ER_TABLE_EXISTS_ERROR,
+                              "Discover of table %s.%s failed",
+                              db, file_name);
+          continue;
+        }
+        pthread_mutex_unlock(&LOCK_open);
+      }
       DBUG_PRINT("info", ("%s existed in NDB _and_ on disk ", file_name));
       file_on_disk= TRUE;
     }