1384198 - Lightning hangs with Yearly rule and BYDAY + BYMONTHDAY with values that don't match

Status: NEW

(Calendar :: Internal Components, defect)

Description

[Jean-Milost Reymond]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170628075643

Steps to reproduce:

I tried to import the following .ics file:
BEGIN:VCALENDAR
VERSION:2.0
PRODID:CopyTrans Contacts
BEGIN:VEVENT
SUMMARY:Yearly G
CATEGORIES:WindSolutions
DTSTART:20150914T190000Z
DTEND:20150914T200000Z
CREATED:20160617T195112Z
RRULE:FREQ=YEARLY;INTERVAL=1;UNTIL=20220103T025959Z;BYDAY=-1TH;BYMONTHDAY=9
END:VEVENT
END:VCALENDAR



Actual results:

Thunderbird became completely frozen. I was forced to kill it. After trying to open again, Thunderbird just remained open in background, refused to show the user interface, and did nothing else. I was obliged to kill Thunderbird again, then open my profile folder and manually delete the calendar-data dir to unblock the situation.


Expected results:

Importing the iCal content in my calendar.

Comment 1

[Decathlon]

I can confirm without testing on both libical and ical.js.

During the initialization of the iterator, an infinite loop arises for a yearly rule when BYDAY and BYMONTHDAY have values impossible to match in any year, like those ones in calendar for test.

With reference to ical.js, the function expand_year_days() returns an empty |this.days| array for every iteration:
https://dxr.mozilla.org/comm-central/source/calendar/base/modules/ical.js#6971
https://dxr.mozilla.org/comm-central/source/calendar/libical/src/libical/icalrecur.c#1007

At first glance it would need a counter that sets a maximum number of iterations.