From bce3b46aaf8c7ad7ff7eeaafbf4b321ffdad9c07 Mon Sep 17 00:00:00 2001
From: Gibeom Gwon <gb.gwon@stackframe.dev>
Date: Sun, 6 Mar 2022 09:45:38 +0900
Subject: [PATCH] calendarspec: fix possibly skips next elapse

If the time unit changes after adding the repetition value, the
timer may skip the next elapse. This patch reset sub time units
to minimum value when upper unit is changed.

Fixes #22665.

(cherry picked from commit 1e582ede3b04d12aae11fc5378a446a392054f1c)
(cherry picked from commit 8d4c0d2383e72f30753bf33f206387bc03879ff8)

Conflict:NA
Reference:https://github.com/systemd/systemd-stable/commit/bce3b46aaf8c7ad7ff7eeaafbf4b321ffdad9c07
---
 src/shared/calendarspec.c    | 27 ++++++++++++++++++++-------
 src/test/test-calendarspec.c |  2 ++
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c
index bf24d8d5bb..238766c96a 100644
--- a/src/shared/calendarspec.c
+++ b/src/shared/calendarspec.c
@@ -1180,6 +1180,7 @@ static int find_matching_component(
 
 static int tm_within_bounds(struct tm *tm, bool utc) {
         struct tm t;
+        int cmp;
         assert(tm);
 
         /*
@@ -1194,13 +1195,25 @@ static int tm_within_bounds(struct tm *tm, bool utc) {
         if (mktime_or_timegm(&t, utc) < 0)
                 return negative_errno();
 
-        /* Did any normalization take place? If so, it was out of bounds before */
-        int cmp = CMP(t.tm_year, tm->tm_year) ?:
-                  CMP(t.tm_mon, tm->tm_mon) ?:
-                  CMP(t.tm_mday, tm->tm_mday) ?:
-                  CMP(t.tm_hour, tm->tm_hour) ?:
-                  CMP(t.tm_min, tm->tm_min) ?:
-                  CMP(t.tm_sec, tm->tm_sec);
+        /*
+         * Did any normalization take place? If so, it was out of bounds before.
+         * Normalization could skip next elapse, e.g. result of normalizing 3-33
+         * is 4-2. This skips 4-1. So reset the sub time unit if upper unit was
+         * out of bounds. Normalization has occurred implies find_matching_component() > 0,
+         * other sub time units are already reset in find_next().
+         */
+        if ((cmp = CMP(t.tm_year, tm->tm_year)) != 0)
+                t.tm_mon = 0;
+        else if ((cmp = CMP(t.tm_mon, tm->tm_mon)) != 0)
+                t.tm_mday = 1;
+        else if ((cmp = CMP(t.tm_mday, tm->tm_mday)) != 0)
+                t.tm_hour = 0;
+        else if ((cmp = CMP(t.tm_hour, tm->tm_hour)) != 0)
+                t.tm_min = 0;
+        else if ((cmp = CMP(t.tm_min, tm->tm_min)) != 0)
+                t.tm_sec = 0;
+        else
+                cmp = CMP(t.tm_sec, tm->tm_sec);
 
         if (cmp < 0)
                 return -EDEADLK; /* Refuse to go backward */
diff --git a/src/test/test-calendarspec.c b/src/test/test-calendarspec.c
index 4f1d0f64d5..bc5e56a238 100644
--- a/src/test/test-calendarspec.c
+++ b/src/test/test-calendarspec.c
@@ -201,6 +201,8 @@ int main(int argc, char* argv[]) {
         test_next("2016-02~01 UTC", "", 12345, 1456704000000000);
         test_next("Mon 2017-05~01..07 UTC", "", 12345, 1496016000000000);
         test_next("Mon 2017-05~07/1 UTC", "", 12345, 1496016000000000);
+        test_next("*-*-01/5 04:00:00 UTC", "", 1646010000000000, 1646107200000000);
+        test_next("*-01/7-01 04:00:00 UTC", "", 1664607600000000, 1672545600000000);
         test_next("2017-08-06 9,11,13,15,17:00 UTC", "", 1502029800000000, 1502031600000000);
         test_next("2017-08-06 9..17/2:00 UTC", "", 1502029800000000, 1502031600000000);
         test_next("2016-12-* 3..21/6:00 UTC", "", 1482613200000001, 1482634800000000);
-- 
2.33.0