time/ISO8601: support omitting seconds

src/time/ISO8601.cxx

@@ -133,12 +133,15 @@ ParseISO8601(const char *s)
 	/* parse the time of day */
 	if (*s == 'T') {
 		++s;
-		end = strptime(s, "%T", &tm);
-		if (end == nullptr)
+
+		if ((end = strptime(s, "%T", &tm)) != nullptr)
+			precision = std::chrono::seconds(1);
+		else if ((end = strptime(s, "%H:%M", &tm)) != nullptr)
+			precision = std::chrono::minutes(1);
+		else
 			throw std::runtime_error("Failed to parse time of day");
 
 		s = end;
-		precision = std::chrono::seconds(1);
 	}
 
 	auto tp = TimeGm(tm);

test/TestISO8601.cxx

@@ -58,6 +58,10 @@ static constexpr struct {
 	/* without time zone */
 	{ "2019-02-04T16:46:41", 1549298801, std::chrono::seconds(1) },
 
+	/* without seconds */
+	{ "2019-02-04T16:46", 1549298760, std::chrono::minutes(1) },
+	{ "2019-02-04T16:46Z", 1549298760, std::chrono::minutes(1) },
+
 	/* with time zone */
 	{ "2019-02-04T16:46:41+02", 1549291601, std::chrono::seconds(1) },
 	{ "2019-02-04T16:46:41+0200", 1549291601, std::chrono::seconds(1) },