Fixes the bug of ecma_date_make_day() (#1836) & ecma_date_week_day(). (#1466)

The ecma_date_make_day() handled any date in October on leap years incorrectly,
which was mentioned in issue #1836. The ecma_date_week_day() returned minus values
when return week_day before 1970 years which was also incorrect.

This change solves these bugs. In addition, this enhances the algorithm of accessing 'the ym-mn-1'
by replacing binary search to simple computation at ecma_date_make_day().

JerryScript-DCO-1.0-Signed-off-by: Hayun Lee lhy920806@gmail.com

tests/jerry/regression-test-issue-1386.js

@@ -0,0 +1,24 @@
+// Copyright 2016 Hayun Lee (lhy920806@gmail.com)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+for (var y = 1950; y < 2050; y++) {
+  for (var m = 0; m < 12; m++) {
+    var last_date = new Date(y, m, 1).getDay ();
+    assert (!isNaN (last_date));
+    for (var d = 1; d < 32; d++) {
+      assert (last_date == new Date(y, m, d).getDay ());
+      last_date = (last_date + 1) % 7;
+    }
+  }
+}

tests/unit/test-date-helpers.c

@@ -162,6 +162,8 @@ main ()
   TEST_ASSERT (ecma_date_make_day (1970, 1, 35) == 65);
   TEST_ASSERT (ecma_date_make_day (1970, 13, 35) == 430);
   TEST_ASSERT (ecma_date_make_day (2016, 2, 1) == 16861);
+  TEST_ASSERT (ecma_date_make_day (2016, 8, 31) == 17075);
+  TEST_ASSERT (ecma_date_make_day (2016, 9, 1) == 17075);
 
   /* ecma_number_t ecma_date_make_date (day, time) */