apacheGH-37608: [C++][Gandiva] TO_DATE function supports YYYY-MM and YYYY (apache#37609) (#48)

Added fix for case when pattern does not contain day part

### Rationale for this change

TO_DATE Gandiva function returns wrong result if used with pattern 'YYYY-MM' or 'YYYY'.

### What changes are included in this PR?

Add a fix for case when tm_mday is zero to set it to 1

### Are these changes tested?

Added tests that cover described cases

### Are there any user-facing changes?

No

* Closes: apache#37608

Authored-by: DenisTarasyuk <131180287+DenisTarasyuk@users.noreply.github.com>

Signed-off-by: Sutou Kouhei <kou@clear-code.com>

Author: DenisTarasyuk

cpp/src/arrow/util/value_parsing.h

@@ -801,7 +801,7 @@ static inline bool ParseTimestampStrptime(const char* buf, size_t length,
   // ignore the time part
   arrow_vendored::date::sys_seconds secs =
       arrow_vendored::date::sys_days(arrow_vendored::date::year(result.tm_year + 1900) /
-                                     (result.tm_mon + 1) / result.tm_mday);
+                                     (result.tm_mon + 1) / std::max(result.tm_mday, 1));
   if (!ignore_time_in_day) {
     secs += (std::chrono::hours(result.tm_hour) + std::chrono::minutes(result.tm_min) +
              std::chrono::seconds(result.tm_sec));

cpp/src/gandiva/to_date_holder_test.cc

@@ -149,4 +149,33 @@ TEST_F(TestToDateHolder, TestSimpleDateTimeMakeError) {
   EXPECT_EQ(status.IsInvalid(), true) << status.message();
 }
 
+TEST_F(TestToDateHolder, TestSimpleDateYearMonth) {
+  std::shared_ptr<ToDateHolder> to_date_holder;
+  ASSERT_OK(ToDateHolder::Make("YYYY-MM", 1, &to_date_holder));
+
+  auto& to_date = *to_date_holder;
+  bool out_valid;
+  std::string s("2012-12");
+  int64_t millis_since_epoch =
+      to_date(&execution_context_, s.data(), (int)s.length(), true, &out_valid);
+  EXPECT_EQ(millis_since_epoch, 1354320000000);
+
+  s = std::string("2012-01");
+  millis_since_epoch =
+      to_date(&execution_context_, s.data(), (int)s.length(), true, &out_valid);
+  EXPECT_EQ(millis_since_epoch, 1325376000000);
+}
+
+TEST_F(TestToDateHolder, TestSimpleDateYear) {
+  std::shared_ptr<ToDateHolder> to_date_holder;
+  ASSERT_OK(ToDateHolder::Make("YYYY", 1, &to_date_holder));
+
+  auto& to_date = *to_date_holder;
+  bool out_valid;
+  std::string s("1999");
+  int64_t millis_since_epoch =
+      to_date(&execution_context_, s.data(), (int)s.length(), true, &out_valid);
+  EXPECT_EQ(millis_since_epoch, 915148800000);
+}
+
 }  // namespace gandiva