Fix timezone issue with negative offsets

The current code miscalculates the time-zone offsets for time zones that don't
have a full-hour offset and are located west of UTC (e.g. St. John's,
Newfoundland).

Basically it's caused because 33 // 10 == 3, but -33 // 10 != -3.

Take the example of St. John's (-0330). The correct integer timezone should be
3.5 * 3600 (12600), however, since we are not checking for negative module
arithmetic, instead of calculating the timezone for (-3, -30), we are doing it
for (-4, 70), which would be OK... if we had hours of 100 minutes:

  -4 * 100 + 70 = -330

We could fix the code to use proper negative arithmetic (mod -100), but why
bother with the extra complexity? Let's just use absolute numbers and fix the
sign later.

This fixes issue #48.

Commit message written by Felipe Contreras.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

git-remote-hg

@@ -72,12 +72,14 @@ def gitmode(flags):
     return 'l' in flags and '120000' or 'x' in flags and '100755' or '100644'
 
 def gittz(tz):
-    return '%+03d%02d' % (-tz / 3600, -tz % 3600 / 60)
+    sign = 1 if tz < 0 else -1
+    return '%+03d%02d' % (sign * (abs(tz) / 3600), abs(tz) % 3600 / 60)
 
 def hgtz(tz):
     tz = int(tz)
-    tz = ((tz / 100) * 3600) + ((tz % 100) * 60)
-    return -tz
+    sign = 1 if tz < 0 else -1
+    tz = ((abs(tz) / 100) * 3600) + ((abs(tz) % 100) * 60)
+    return sign * tz
 
 def hgmode(mode):
     m = { '100755': 'x', '120000': 'l' }

test/bidi.t

@@ -240,7 +240,7 @@ test_expect_success 'hg tags' '
 	test_cmp expected actual
 '
 
-test_expect_failure 'test timezones' '
+test_expect_success 'test timezones' '
 	test_when_finished "rm -rf gitrepo* hgrepo*" &&
 
 	(

test/main.t

@@ -1052,7 +1052,7 @@ test_expect_success 'push annotated tag' '
 	test_cmp expected actual
 '
 
-test_expect_failure 'timezone issues with negative offsets' '
+test_expect_success 'timezone issues with negative offsets' '
 	test_when_finished "rm -rf hgrepo gitrepo1 gitrepo2" &&
 
 	hg init hgrepo &&