In #5894, in the `add_dynamic_sexp` function in sexp_lookup.cpp, a call to `sexp->getHelpText()` was moved to the bottom of the function. Normally this would be fine, except that this occasion caused the `sexp` variable to be accessed after a `std::move`. The crash can be avoided by moving the last access of the `sexp` variable just a little bit earlier.
In #5649 / b6c0e8b, the ship registry was updated to take ship death rolls into account. There was one small wrinkle that it did not account for, however: SEXP operators that return numeric values had previously (i.e. before the introduction of the ship registry) checked the mission log for ship destruction, but after #5649 the EXITED status was not set until after the ship had completely exploded, resulting in certain SEXPs having their conditions slightly modified. The equivalent of checking the mission log for ship destruction is now checking the ship status for DEATH_ROLL, so it is necessary to make that change for the numeric SEXPs to behave as they did before.
The motivating result for all this is to fix SEXPs like `hits-left` firing after a ship has been destroyed but before it has finished exploding. This can be seen by loading the first non-training mission of FSPort and comparing the messages that are sent if you use cheats to kill Alpha 2.
SEXP helps should let the FREDder know whether a given ship argument
needs to be already in-mission for the SEXPression to operate. Update
the helps to include (ship needs to be in-mission) or (ship does not
need to be in-mission) or other relevant helpful information.
Since its creation, the `is-in-mission` sexp operator has only checked for ships. But mission designers might assume this also works for wings, leading to a situation where the sexp always returns false because no ship can have the same name as a wing. Fortunately wing functionality can be added to this sexp without affecting ship functionality.
This fixes a few items that were revealed in the course of Dark Visor's SEXP documentation PR. The EXITED status should return NAN_FOREVER, not just NAN. The CANT_EVAL value is never returned from the sexp on account of ship status, due to the preceding check, and is not an appropriate return value anyway; so that is removed. Finally, for a ship that can't move, the NAN return value is better than CANT_EVAL, since it represents the numeric situation more accurately and can also be checked by `is-nan`.
This is a new method of ensuring that OPF_POSITIVE numbers are positive. It works for all numeric arguments, including variables and literals, and caches the status of the node to avoid lookups for every negative number on every frame. Tested on both operator and non-operator cases.
Follow-up to #5915.
Operators that specify OPF_POSITIVE should be guaranteed to get positive numbers. This code was previously disabled for performance reasons, but following the contract of the SEXP system is more important. A future PR will improve the performance of the functions used here.
Also, the `num-players` operator takes no arguments, so fix that.
1. Allow a `+` to appear in front of numbers, just as with `-`
2. Check for `.` and `,` within numbers to give a less misleading error message than "not a number"
3. The old number hack inadvertently skipped numeric literals, so specifically check for those
There are several SEXP argument types that themselves encompass multiple argument types: for example, ships and wings. This could be misleading when there is an error message displayed. So, this updates the error codes to explicitly cover all of the possibilities.
This refactors the ship registry and the OSWPT struct to store data as indexes rather than pointers. This is a prerequisite for making these collections dynamic in the future. See also #5800.
Goober5000