From 1a73e77463ff19554a2c913b1e9e54bc69e52ce7 Mon Sep 17 00:00:00 2001
From: Pavel Kartavyy <kartavyy@yandex-team.ru>
Date: Fri, 29 Aug 2014 22:44:44 +0400
Subject: [PATCH] dbms: fixed exception in TinyLog when it is empty
 [#METR-12532]

---
 dbms/include/DB/Storages/StorageTinyLog.h                 | 2 ++
 dbms/src/Storages/StorageTinyLog.cpp                      | 8 +++++++-
 .../queries/0_stateless/00068_empty_tiny_log.reference    | 0
 dbms/tests/queries/0_stateless/00068_empty_tiny_log.sql   | 5 +++++
 4 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 dbms/tests/queries/0_stateless/00068_empty_tiny_log.reference
 create mode 100644 dbms/tests/queries/0_stateless/00068_empty_tiny_log.sql

diff --git a/dbms/include/DB/Storages/StorageTinyLog.h b/dbms/include/DB/Storages/StorageTinyLog.h
index d91cc88d9a3..770259f69d4 100644
--- a/dbms/include/DB/Storages/StorageTinyLog.h
+++ b/dbms/include/DB/Storages/StorageTinyLog.h
@@ -144,6 +144,8 @@ public:
 
 	Files_t & getFiles();
 
+	std::string full_path() { return path + escapeForFileName(name) + '/';} 
+
 private:
 	String path;
 	String name;
diff --git a/dbms/src/Storages/StorageTinyLog.cpp b/dbms/src/Storages/StorageTinyLog.cpp
index d48cbea70e3..92b5a0cc65a 100644
--- a/dbms/src/Storages/StorageTinyLog.cpp
+++ b/dbms/src/Storages/StorageTinyLog.cpp
@@ -16,7 +16,7 @@
 #include <DB/Columns/ColumnNested.h>
 
 #include <DB/Storages/StorageTinyLog.h>
-
+#include <Poco/DirectoryIterator.h>
 
 #define DBMS_STORAGE_LOG_DATA_FILE_EXTENSION 	".bin"
 
@@ -61,6 +61,12 @@ Block TinyLogBlockInputStream::readImpl()
 		return res;
 	}
 
+	{
+		/// если в папке нет файлов, то это значит, что таблица пока пуста
+		if (Poco::DirectoryIterator(storage.full_path()) == Poco::DirectoryIterator())
+			return res;
+	}
+
 	/// Если файлы не открыты, то открываем их.
 	if (streams.empty())
 		for (Names::const_iterator it = column_names.begin(); it != column_names.end(); ++it)
diff --git a/dbms/tests/queries/0_stateless/00068_empty_tiny_log.reference b/dbms/tests/queries/0_stateless/00068_empty_tiny_log.reference
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/dbms/tests/queries/0_stateless/00068_empty_tiny_log.sql b/dbms/tests/queries/0_stateless/00068_empty_tiny_log.sql
new file mode 100644
index 00000000000..620f872a3d8
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00068_empty_tiny_log.sql
@@ -0,0 +1,5 @@
+CREATE TABLE IF NOT EXISTS test_empty_tiny_log(A UInt8) Engine = TinyLog;
+
+SELECT A FROM test_empty_tiny_log;
+
+DROP TABLE  test_empty_tiny_log;