time: fix parsing of minutes in time zones.

R=r
CC=golang-dev
https://golang.org/cl/1830041

src/pkg/time/format.go

@@ -522,7 +522,7 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
 			}
 			var hr, min int
 			hr, err = strconv.Atoi(hh)
-			if err != nil {
+			if err == nil {
 				min, err = strconv.Atoi(mm)
 			}
 			t.ZoneOffset = (hr*60 + min) * 60 // offset is in seconds

src/pkg/time/time_test.go

@@ -303,6 +303,17 @@ func TestMissingZone(t *testing.T) {
 	}
 }
 
+func TestMinutesInTimeZone(t *testing.T) {
+	time, err := Parse(RubyDate, "Mon Jan 02 15:04:05 +0123 2006")
+	if err != nil {
+		t.Fatal("error parsing date:", err)
+	}
+	expected := (1*60 + 23) * 60
+	if time.ZoneOffset != expected {
+		t.Errorf("ZoneOffset incorrect, expected %d got %d", expected, time.ZoneOffset)
+	}
+}
+
 func BenchmarkSeconds(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		Seconds()