time: make parse_iso8601 support format without microseconds (#7176)

vlib/time/parse.v

@@ -51,7 +51,7 @@ pub fn parse_rfc2822(s string) ?Time {
 // parse_iso8601 parses rfc8601 time format yyyy-MM-ddTHH:mm:ss.dddddd+dd:dd as local time
 // the fraction part is difference in milli seconds and the last part is offset
 // from UTC time and can be both +/- HH:mm
-// remarks: not all iso8601 is supported only the 'yyyy-MM-ddTHH:mm:ss.dddddd+dd:dd'
+// remarks: not all iso8601 is supported
 // also checks and support for leapseconds should be added in future PR
 pub fn parse_iso8601(s string) ?Time {
 	year := 0
@@ -65,9 +65,16 @@ pub fn parse_iso8601(s string) ?Time {
 	plus_min_z := `a`
 	offset_hour := 0
 	offset_min := 0
-	count := unsafe {C.sscanf(charptr(s.str), '%4d-%2d-%2d%c%2d:%2d:%2d.%6d%c%2d:%2d',
+	mut count := unsafe {C.sscanf(charptr(s.str), '%4d-%2d-%2d%c%2d:%2d:%2d.%6d%c%2d:%2d',
 		&year, &month, &day, charptr(&time_char), &hour, &minute, &second, &mic_second, charptr(&plus_min_z),
 		&offset_hour, &offset_min)}
+	// Missread microsec ([Year Month Day T Sec Hour Minute].len == 7 < 8)
+	if count < 8 {
+		count = unsafe {C.sscanf(charptr(s.str), '%4d-%2d-%2d%c%2d:%2d:%2d%c%2d:%2d',
+			&year, &month, &day, charptr(&time_char), &hour, &minute, &second, charptr(&plus_min_z),
+			&offset_hour, &offset_min)}
+		count++ // Increment count because skipped microsec
+	}
 	is_local_time := plus_min_z == `a` && count == 8
 	is_utc := plus_min_z == `Z` && count == 9
 	if count != 11 && !is_local_time && !is_utc {

vlib/time/parse_test.v

@@ -49,13 +49,25 @@ fn test_parse_rfc2822_invalid() {
 }
 
 fn test_iso8601_parse_utc() {
-	format_utc := '2020-06-05T15:38:06.015959Z'
-	t_utc := time.parse_iso8601(format_utc) or {
-		panic(err)
+	formats := [
+		'2020-06-05T15:38:06.015959Z',
+		'2020-06-05T15:38:06Z',
+	]
+	times := [
+		[2020, 6, 5, 15, 38, 6, 15959],
+		[2020, 6, 5, 15, 38, 6, 0],
+	]
+	for i, format in formats {
+		t := time.parse_iso8601(format) or { panic(err) }
+		tt := times[i]
+		assert t.year == tt[0]
+		assert t.month == tt[1]
+		assert t.day == tt[2]
+		assert t.hour == tt[3]
+		assert t.minute == tt[4]
+		assert t.second == tt[5]
+		assert t.microsecond == tt[6]
 	}
-	assert t_utc.year == 2020
-	assert t_utc.month == 6
-	assert t_utc.day == 5
 }
 
 fn test_iso8601_parse_local() {