Bug#35333, "If Federated table can't connect to remote host, can't retrieve

metadata"
            
Improved error handling such that queries against Information_Schema.Tables won't
fail if a federated table can't make a remote connection.

mysql-test/r/merge.result:
  Updated with warnings that were previously masked.
mysql-test/r/show_check.result:
  Updated with warnings that were previously masked.
mysql-test/r/view.result:
  Updated with warnings that were previously masked.
sql/sql_show.cc:
  If get_schema_tables_record() encounters an error, push a warning,
  set the TABLE COMMENT column with the error text, and clear the
  error so that the operation can continue.

1 files changed, 34 insertions, 9 deletions

diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 9b344204d64..ee0e2bf5ce7 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -3636,28 +3636,28 @@ static int get_schema_tables_record(THD *thd, TABLE_LIST *tables,
 {
   const char *tmp_buff;
   MYSQL_TIME time;
+  int info_error= 0;
   CHARSET_INFO *cs= system_charset_info;
   DBUG_ENTER("get_schema_tables_record");
 
   restore_record(table, s->default_values);
   table->field[1]->store(db_name->str, db_name->length, cs);
   table->field[2]->store(table_name->str, table_name->length, cs);
+
   if (res)
   {
-    /*
-      there was errors during opening tables
-    */
-    const char *error= thd->is_error() ? thd->main_da.message() : "";
+    /* There was a table open error, so set the table type and return */
     if (tables->view)
       table->field[3]->store(STRING_WITH_LEN("VIEW"), cs);
     else if (tables->schema_table)
       table->field[3]->store(STRING_WITH_LEN("SYSTEM VIEW"), cs);
     else
       table->field[3]->store(STRING_WITH_LEN("BASE TABLE"), cs);
-    table->field[20]->store(error, strlen(error), cs);
-    thd->clear_error();
+
+    goto err;
   }
-  else if (tables->view)
+
+  if (tables->view)
   {
     table->field[3]->store(STRING_WITH_LEN("VIEW"), cs);
     table->field[20]->store(STRING_WITH_LEN("VIEW"), cs);
@@ -3746,9 +3746,14 @@ static int get_schema_tables_record(THD *thd, TABLE_LIST *tables,
     if (share->comment.str)
       table->field[20]->store(share->comment.str, share->comment.length, cs);
 
-    if(file)
+    if (file)
     {
-      file->info(HA_STATUS_VARIABLE | HA_STATUS_TIME | HA_STATUS_AUTO);
+      /* If info() fails, then there's nothing else to do */
+      if ((info_error= file->info(HA_STATUS_VARIABLE |
+                                  HA_STATUS_TIME |
+                                  HA_STATUS_AUTO)) != 0)
+        goto err;
+	  
       enum row_type row_type = file->get_row_type();
       switch (row_type) {
       case ROW_TYPE_NOT_USED:
@@ -3826,6 +3831,26 @@ static int get_schema_tables_record(THD *thd, TABLE_LIST *tables,
       }
     }
   }
+
+err:
+  if (res || info_error)
+  {
+    /*
+      If an error was encountered, push a warning, set the TABLE COMMENT
+      column with the error text, and clear the error so that the operation
+      can continue.
+    */
+    const char *error= thd->is_error() ? thd->main_da.message() : "";
+    table->field[20]->store(error, strlen(error), cs);
+
+    if (thd->is_error())
+    {
+      push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                   thd->main_da.sql_errno(), thd->main_da.message());
+      thd->clear_error();
+    }
+  }
+  
   DBUG_RETURN(schema_table_store_record(thd, table));
 }