Merge pull request ClickHouse#5 from clrusby/dates_2038

Fix for 2038 date bug

Author: alexey-milovidov

clickhouse/columns/date.cpp

@@ -9,15 +9,15 @@ ColumnDate::ColumnDate()
 }
 
 void ColumnDate::Append(const std::time_t& value) {
-    data_->Append(static_cast<uint16_t>(value / 86400));
+    data_->Append(static_cast<uint16_t>(value / std::time_t(86400)));
 }
 
 void ColumnDate::Clear() {
     data_->Clear();
 }
 
 std::time_t ColumnDate::At(size_t n) const {
-    return data_->At(n) * 86400;
+    return data_->At(n) * std::time_t(86400);
 }
 
 void ColumnDate::Append(ColumnRef column) {

ut/columns_ut.cpp

@@ -112,6 +112,15 @@ TEST(ColumnsCase, DateAppend) {
     ASSERT_EQ(col2->At(0), (now / 86400) * 86400);
 }
 
+TEST(ColumnsCase, Date2038) {
+    auto col1 = std::make_shared<ColumnDate>();
+    std::time_t largeDate(25882ul * 86400ul);
+    col1->Append(largeDate);
+
+    ASSERT_EQ(col1->Size(), 1u);
+    ASSERT_EQ(static_cast<std::uint64_t>(col1->At(0)), 25882ul * 86400ul);
+}
+
 TEST(ColumnsCase, EnumTest) {
     std::vector<Type::EnumItem> enum_items = {{"Hi", 1}, {"Hello", 2}};