Fix for bug#13818 SHOW CREATE VIEW / TABLE and information_schema.views fail

for invalid view
 Permit SHOW CREATE VIEW, SHOW CREATE TABLE, and retrieval of metadata from
 information_schema for invalid views

mysql-test/r/information_schema.result

@@ -647,12 +647,16 @@ drop function sub1;
 select table_name from information_schema.views
 where table_schema='test';
 table_name
+v2
+v3
 Warnings:
 Warning	1356	View 'test.v2' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
 Warning	1356	View 'test.v3' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
 select table_name from information_schema.views
 where table_schema='test';
 table_name
+v2
+v3
 Warnings:
 Warning	1356	View 'test.v2' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
 Warning	1356	View 'test.v3' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
@@ -669,6 +673,16 @@ f1_key
 select constraint_name from information_schema.table_constraints
 where table_schema='test';
 constraint_name
+show create view v2;
+View	Create View
+v2	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v2` AS select `test`.`t1`.`f1` AS `c` from `t1`
+Warnings:
+Warning	1356	View 'test.v2' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
+show create table v3;
+View	Create View
+v3	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v3` AS select sql_no_cache `test`.`sub1`(1) AS `c`
+Warnings:
+Warning	1356	View 'test.v3' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
 drop view v2;
 drop view v3;
 drop table t4;

mysql-test/t/information_schema.test

@@ -379,6 +379,8 @@ where table_schema='test';
 select index_name from information_schema.statistics where table_schema='test';
 select constraint_name from information_schema.table_constraints
 where table_schema='test';
+show create view v2;
+show create table v3;
 drop view v2;
 drop view v3;
 drop table t4;

sql/sql_show.cc

@@ -362,7 +362,21 @@ mysqld_show_create(THD *thd, TABLE_LIST *table_list)
 
   /* Only one table for now, but VIEW can involve several tables */
   if (open_normal_and_derived_tables(thd, table_list, 0))
+  {
+    if (!table_list->view || thd->net.last_errno != ER_VIEW_INVALID)
       DBUG_RETURN(TRUE);
+    /*
+      Clear all messages with 'error' level status and
+      issue a warning with 'warning' level status in 
+      case of invalid view and last error is ER_VIEW_INVALID
+    */
+    mysql_reset_errors(thd, true);
+    push_warning_printf(thd,MYSQL_ERROR::WARN_LEVEL_WARN,
+                        ER_VIEW_INVALID,
+                        ER(ER_VIEW_INVALID),
+                        table_list->view_db.str,
+                        table_list->view_name.str);
+  }
 
   /* TODO: add environment variables show when it become possible */
   if (thd->lex->only_view && !table_list->view)
@@ -2992,8 +3006,7 @@ static int get_schema_views_record(THD *thd, struct st_table_list *tables,
   DBUG_ENTER("get_schema_views_record");
   char definer[HOSTNAME_LENGTH + USERNAME_LENGTH + 2];
   uint definer_len;
-  if (!res)
+
-  {
   if (tables->view)
   {
     restore_record(table, s->default_values);
@@ -3023,16 +3036,14 @@ static int get_schema_views_record(THD *thd, struct st_table_list *tables,
       table->field[7]->store(STRING_WITH_LEN("DEFINER"), cs);
     else
       table->field[7]->store(STRING_WITH_LEN("INVOKER"), cs);
-      DBUG_RETURN(schema_table_store_record(thd, table));
+    if (schema_table_store_record(thd, table))
-    }
+      DBUG_RETURN(1);
-  }
+    if (res)
-  else
-  {
-    if (tables->view)
       push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, 
                    thd->net.last_errno, thd->net.last_error);
-    thd->clear_error();
   }
+  if (res) 
+    thd->clear_error();
   DBUG_RETURN(0);
 }