Bug#17371: Unable to dump a schema with invalid views

'show create' works even on views that are short of a base-table (this
throw a warning though, like you would expect). Unfortunately, this is
not what mysqldump uses; it creates stand-in tables and hence requests
'show fields' on the view which fails with missing base-tables.  The
--force option prevents the dump from stopping at this point; furthermore
this patch dumps a comment showing create for the offending view for
better diagnostics. This solution was confirmed by submitter as solving
their/clients' problem. Problem might become non-issue once mysqldump no
longer creates stand-in tables.


client/mysqldump.c:
  Dump a comment showing create for a view if we can't show fields for it for
  better diagnostics.
mysql-test/r/mysqldump.result:
  add test for #17371 - be defensive. if we can't do a full dump on a view
  (incl. 'show fields' for a stand-in table), at least create a comment with
  the 'show create' info when --force is given.
mysql-test/t/mysqldump.test:
  add test for #17371 - be defensive. if we can't do a full dump on a view
  (incl. 'show fields' for a stand-in table), at least create a comment with
  the 'show create' info when --force is given.

client/mysqldump.c

@@ -1494,9 +1494,15 @@ static uint get_table_structure(char *table, char *db, char *table_type,
       field= mysql_fetch_field_direct(result, 0);
       if (strcmp(field->name, "View") == 0)
       {
+        char *scv_buff = NULL;
+
         if (verbose)
           fprintf(stderr, "-- It's a view, create dummy table for view\n");
 
+        /* save "show create" statement for later */
+        if ((row= mysql_fetch_row(result)) && (scv_buff=row[1]))
+          scv_buff= my_strdup(scv_buff, MYF(0));
+
         mysql_free_result(result);
 
         /*
@@ -1514,9 +1520,22 @@ static uint get_table_structure(char *table, char *db, char *table_type,
                     "SHOW FIELDS FROM %s", result_table);
         if (mysql_query_with_error_report(sock, 0, query_buff))
         {
+          /*
+            View references invalid or privileged table/col/fun (err 1356),
+            so we cannot create a stand-in table.  Be defensive and dump
+            a comment with the view's 'show create' statement. (Bug #17371)
+          */
+
+          if (mysql_errno(sock) == ER_VIEW_INVALID)
+            fprintf(sql_file, "\n-- failed on view %s: %s\n\n", result_table, scv_buff ? scv_buff : "");
+
+          my_free(scv_buff, MYF(MY_ALLOW_ZERO_PTR));
+
           safe_exit(EX_MYSQLERR);
-          DBUG_RETURN(0);
+          DBUG_RETURN(0); 
         }
+        else
+          my_free(scv_buff, MYF(MY_ALLOW_ZERO_PTR));
 
         if ((result= mysql_store_result(sock)))
         {

mysql-test/r/mysqldump.result

@@ -2731,3 +2731,12 @@ p		CREATE DEFINER=`root`@`localhost` PROCEDURE `p`()
 select 42
 drop function f;
 drop procedure p;
+create table t1 ( id serial );
+create view v1 as select * from t1;
+drop table t1;
+mysqldump {
+
+-- failed on view `v1`: CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select `test`.`t1`.`id` AS `id` from `t1`
+
+} mysqldump
+drop view v1;

mysql-test/t/mysqldump.test

@@ -1143,3 +1143,16 @@ show create procedure p;
 drop function f;
 drop procedure p;
 
+#
+# Bug #17371 Unable to dump a schema with invalid views
+#
+#
+create table t1 ( id serial );
+create view v1 as select * from t1;
+drop table t1;
+# mysqldump gets 1356 from server, but gives us 2
+--echo mysqldump {
+--error 2
+--exec $MYSQL_DUMP --force -N --compact --skip-comments test
+--echo } mysqldump
+drop view v1;