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| author | Lars Henriksen <LarsHenriksen@get2net.dk> | 2019-04-27 23:28:52 +0200 |
|---|---|---|
| committer | Lukas Fleischer <lfleischer@calcurse.org> | 2019-05-20 09:37:11 -0400 |
| commit | 2be32c4bda5236ec19e0f3c544adcd2974684f50 (patch) | |
| tree | e7a58d113e3562a5e8227af9a60897444c3cc20a | |
| parent | 8741334d83aa5f77f1169af70493f394f860779f (diff) | |
| download | calcurse-2be32c4bda5236ec19e0f3c544adcd2974684f50.tar.gz calcurse-2be32c4bda5236ec19e0f3c544adcd2974684f50.zip | |
Impossible dates in recurrence rules
According to RFC 5545 dates like 30 February and 31 June must be ignored
when derived from a recurrence rule.
calcurse relies on mktime() "normalization" of dates (e.g. turning 32
December 2019 into 1 January 2020 when moving from 31 December to the
next day).
Normalization may also lead to impossible dates in monthly and yearly
recurrence rules, and this must be avoided.
Signed-off-by: Lars Henriksen <LarsHenriksen@get2net.dk>
Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>
| -rw-r--r-- | src/recur.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/recur.c b/src/recur.c index 4e8bd09..46f669d 100644 --- a/src/recur.c +++ b/src/recur.c @@ -815,6 +815,18 @@ recur_item_find_occurrence(time_t item_start, long item_dur, lt_item_day.tm_isdst = lt_day.tm_isdst; t = mktime(<_item_day); + /* + * Impossible dates must be ignored (according to RFC 5545). Changing + * only the year or the month may lead to dates like 29 February in + * non-leap years or 31 November. + */ + if (rpt_type == RECUR_MONTHLY || rpt_type == RECUR_YEARLY) { + localtime_r(&t, <_item_day); + if (lt_item_day.tm_mday != lt_item.tm_mday) + return 0; + } + + /* Exception day? */ if (LLIST_FIND_FIRST(item_exc, &t, exc_inday)) return 0; |