Bug#42364 SHOW ERRORS returns empty resultset after dropping non existent table

enabled message storing into error message list
for 'drop table' command


mysql-test/r/warnings.result:
  test result
mysql-test/t/warnings.test:
  test case
sql/sql_table.cc:
  We should skip error sending then we should return
  warnings to client as some functions may send its
  own errors, so we should set no_warnings_for_error= 0
  only in case of warning.
  The fix is to enable message storing into error message
  list for 'drop table' command(only for error case).
tests/mysql_client_test.c:
  test fix

mysql-test/r/warnings.result

@@ -313,4 +313,9 @@ ERROR 22001: Data too long for column 'c_tinytext' at row 1
 insert into t2 values(@q);
 ERROR 22001: Data too long for column 'c_tinyblob' at row 1
 drop table t1, t2;
+DROP TABLE t1;
+ERROR 42S02: Unknown table 't1'
+SHOW ERRORS;
+Level	Code	Message
+Error	1051	Unknown table 't1'
 End of 5.0 tests

mysql-test/t/warnings.test

@@ -225,4 +225,11 @@ insert into t2 values(@q);
 
 drop table t1, t2;
 
+#
+# Bug#42364 SHOW ERRORS returns empty resultset after dropping non existent table
+#
+--error ER_BAD_TABLE_ERROR
+DROP TABLE t1;
+SHOW ERRORS;
+
 --echo End of 5.0 tests

sql/sql_table.cc

@@ -1995,6 +1995,7 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
   pthread_mutex_unlock(&LOCK_open);
   thd->thread_specific_used|= tmp_table_deleted;
   error= 0;
+  thd->no_warnings_for_error= 0;
   if (wrong_tables.length())
   {
     if (!foreign_key_error)
@@ -2056,7 +2057,6 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
 err_with_placeholders:
   unlock_table_names(thd, tables, (TABLE_LIST*) 0);
   pthread_mutex_unlock(&LOCK_open);
-  thd->no_warnings_for_error= 0;
   DBUG_RETURN(error);
 }
 

tests/mysql_client_test.c

@@ -4769,6 +4769,8 @@ static void test_errors()
   result= mysql_store_result(mysql);
   mytest(result);
 
+  DIE_UNLESS(mysql_num_rows(result) == 1);
+
   (void) my_process_result_set(result);
   mysql_free_result(result);
 }