Make use of until parameter in nextMonthly function

[jaircuevajunior]

Hello there,

I've felt the need of this PR becauase of a buggy event:
FREQ=MONTHLY;
INTERVAL=1;
BYMONTHDAY=2;
BYDAY=2WE;
WKST=WE;
UNTIL=20211214T000000Z

The "Until" was not being taken into account, so it was falling into the 10000 year problem.

[staabm]

Thanks for the PR.

Could you add unit test which fails without your fix?

[jaircuevajunior]

The problem is that this is a performance issue...
If you get this rule, you'll realize it's an impossible rule, because of the BYMONTHDAY=2;.
When the object receives an impossible rule, it will loop through all the possibilities until it reaches this breakpoint:

            // To prevent running this forever (better: until we hit the max date of DateTimeImmutable) we simply
            // stop at 9999-12-31. Looks like the year 10000 problem is not solved in php ....
            if ($this->currentDate->getTimestamp() > 253402300799) {
                $this->currentDate = null;

                return;
            }

But it could stop the loop as soon as it arrives the until parameter as proposed in my PR:

            // For some reason the "until" parameter was not being used here,
            // that's why the workaround of the 10000 year bug was needed at all
            // let's stop it before the "until" parameter date
            if ($this->until && $this->currentDate->getTimestamp() >= $this->until->getTimestamp()) {
                return;
            }

In both cases the result is gonna be the same, but the process will be much faster with my purposed fix.

NOTE: Obviously, this is only working when the until parameter is set, otherwise it'll run untill the 10000 year as normally expected.

Now i have runned the tests, found an error and fixed it, but I don't know the right way of creating a test for this case since it's a performance issue... I don't want to create a test using the time as a parameter to fail the test... any idea?

[codecov]

Codecov Report

Merging #532 (1bbae65) into master (3168acd) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##             master     #532   +/-   ##
=========================================
  Coverage     98.69%   98.69%           
- Complexity     1757     1759    +2     
=========================================
  Files            66       66           
  Lines          4277     4279    +2     
=========================================
+ Hits           4221     4223    +2     
  Misses           56       56           

Impacted Files	Coverage Δ	Complexity Δ
lib/Recur/RRuleIterator.php	99.41% <100.00%> (+<0.01%)	155.00 <0.00> (+2.00)

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[phil-davis]

LGTM