Merge pull request #2335 from ChanceNCounter/bug/day-after-tomorrow

Fixes index error in parse_en.extract_datetime()

mycroft/util/lang/parse_en.py

@@ -828,7 +828,7 @@ def extract_datetime_en(string, dateNow, default_time):
               wordNext == "after" and
               wordNextNext == "tomorrow" and
               not fromFlag and
-              not wordPrev[0].isdigit()):
+              not (wordPrev[0].isdigit() if wordPrev else False)):
             dayOffset = 2
             used = 3
             if wordPrev == "the":

test/unittests/util/test_parse.py

@@ -254,6 +254,8 @@ class TestNormalize(unittest.TestCase):
                     "2017-07-02 00:00:00", "set ambush")
         testExtract("What is the day after tomorrow's weather?",
                     "2017-06-29 00:00:00", "what is weather")
+        testExtract("day after tomorrow",
+                    "2017-06-29 00:00:00", "")
         testExtract("Remind me at 10:45 pm",
                     "2017-06-27 22:45:00", "remind me")
         testExtract("what is the weather on friday morning",