From bd238bfd7c443fd974f5b7edd6c1abc0349bfa78 Mon Sep 17 00:00:00 2001 From: Lars Henriksen Date: Thu, 7 May 2020 21:39:23 +0200 Subject: Fix recurrence rule expansion with ordered weekday When the order of a weekday in BYDAY rule expansion (like -5SA or 5SU for monthly or 55WE for yearly) exceeds the number of available weekdays in the period (month or year), rule expansion with negative order could result in a floating point exception. The reason: the modified frequency might become zero. Solution. Check order against number of available weekdays and terminate expansion early whenever possible (also for positive orders). Signed-off-by: Lars Henriksen Signed-off-by: Lukas Fleischer --- src/recur.c | 63 +++++++++++++++++++++++++++++++++++++------------------ test/data/rfc5545 | 1 + test/recur-009.sh | 13 ++++++++++++ 3 files changed, 57 insertions(+), 20 deletions(-) diff --git a/src/recur.c b/src/recur.c index 997fb15..647ba11 100644 --- a/src/recur.c +++ b/src/recur.c @@ -1173,7 +1173,7 @@ static int expand_monthly(time_t start, long dur, struct rpt *rpt, llist_t *exc, LLIST_FOREACH(&rpt->bywday, i) { w = LLIST_GET_DATA(i); - int order, wday; + int order, wday, nbwd; localtime_r(&start, &tm_start); /* @@ -1188,6 +1188,11 @@ static int expand_monthly(time_t start, long dur, struct rpt *rpt, llist_t *exc, */ order = *w / WEEKINDAYS; wday = *w % WEEKINDAYS; + nbwd = wday_per_month(tm_day.tm_mon + 1, + tm_day.tm_year + 1900, + wday); + if (nbwd < order) + return 0; r.freq = order; tm_start.tm_mday = 1; tm_start.tm_mon = tm_day.tm_mon; @@ -1218,11 +1223,12 @@ static int expand_monthly(time_t start, long dur, struct rpt *rpt, llist_t *exc, */ order = -(*w) / WEEKINDAYS; wday = -(*w) % WEEKINDAYS; - r.freq = wday_per_month( - tm_day.tm_mon + 1, - tm_day.tm_year + 1900, - wday - ) - order + 1; + nbwd = wday_per_month(tm_day.tm_mon + 1, + tm_day.tm_year + 1900, + wday); + if (nbwd < order) + return 0; + r.freq = nbwd - order + 1; tm_start.tm_mday = 1; tm_start.tm_mon = tm_day.tm_mon; tm_start.tm_year = tm_day.tm_year; @@ -1259,7 +1265,7 @@ static int expand_yearly(time_t start, long dur, struct rpt *rpt, llist_t *exc, { struct tm tm_start, tm_day; llist_item_t *i, *j; - int *m, *w, mday, wday, order; + int *m, *w, mday, wday, order, nbwd; time_t nstart; struct rpt r; @@ -1312,6 +1318,19 @@ static int expand_yearly(time_t start, long dur, struct rpt *rpt, llist_t *exc, */ order = *w / WEEKINDAYS; wday = *w % WEEKINDAYS; + if (rpt->bymonth.head) + nbwd = wday_per_month( + tm_day.tm_mon + 1, + tm_day.tm_year + 1900, + wday + ); + else + nbwd = wday_per_year( + tm_day.tm_year + 1900, + wday + ); + if (nbwd < order) + return 0; r.freq = order; tm_start.tm_mday = 1; if (rpt->bymonth.head) @@ -1344,21 +1363,25 @@ static int expand_yearly(time_t start, long dur, struct rpt *rpt, llist_t *exc, */ order = -(*w) / WEEKINDAYS; wday = -(*w) % WEEKINDAYS; - if (rpt->bymonth.head) { - r.freq = wday_per_month( - tm_day.tm_mon + 1, - tm_day.tm_year + 1900, - wday - ) - order + 1; + if (rpt->bymonth.head) + nbwd = wday_per_month( + tm_day.tm_mon + 1, + tm_day.tm_year + 1900, + wday + ); + else + nbwd = wday_per_year( + tm_day.tm_year + 1900, + wday + ); + if (nbwd < order) + return 0; + r.freq = nbwd - order + 1; + tm_start.tm_mday = 1; + if (rpt->bymonth.head) tm_start.tm_mon = tm_day.tm_mon; - } else { - r.freq = wday_per_year( - tm_day.tm_year + 1900, - wday - ) - order + 1; + else tm_start.tm_mon = 0; - } - tm_start.tm_mday = 1; tm_start.tm_year = tm_day.tm_year; tm_start.tm_isdst = -1; nstart = date_sec_change( diff --git a/test/data/rfc5545 b/test/data/rfc5545 index 421dd53..d9863ce 100644 --- a/test/data/rfc5545 +++ b/test/data/rfc5545 @@ -25,3 +25,4 @@ 12/25/1997 [1] {3Y w-11} Last Thursday of the year every third year, forever (FREQ=YEARLY;INTERVAL=3;BYDAY=-1TH) 06/22/1997 [1] {2Y w0 w1} Every Sunday and Monday, every other year (FREQ=YEARLY;INTERVAL=2;BYDAY=SU,MO) 02/01/1997 [1] {1Y -> 01/31/2005 d1 d29 m2} Every year on February 1 and 29 for eight years (RRULE:FREQ=YEARLY;UNTIL=20050131T000000Z;BYMONTH=2;BYMONTHDAY=1,29) +08/01/2020 @ 08:41 -> 08/01/2020 @ 10:11 {1M w-41} |negative ordered weekday may not exist diff --git a/test/recur-009.sh b/test/recur-009.sh index 6ee302d..2558b4c 100755 --- a/test/recur-009.sh +++ b/test/recur-009.sh @@ -6,6 +6,13 @@ if [ "$1" = 'actual' ]; then "$CALCURSE" --read-only -D "$DATA_DIR"/ -c "$DATA_DIR/rfc5545" \ -Q --from 1/1/1996 --to 12/31/2007 --filter-type recur + echo "" + echo "Floating point exception?" + "$CALCURSE" --read-only -D "$DATA_DIR"/ -c "$DATA_DIR/rfc5545" \ + -Q --day 8/1/2020 --filter-type recur && + "$CALCURSE" --read-only -D "$DATA_DIR"/ -c "$DATA_DIR/rfc5545" \ + -Q --day 11/1/2020 --filter-type recur && + echo "No Floating point exception on November 1, 2020" elif [ "$1" = 'expected' ]; then cat < 10:11 + negative ordered weekday may not exist +No Floating point exception on November 1, 2020 EOD else ./run-test "$0" -- cgit v1.2.3