While skimming the differencs in jg18's branch of PR #3253...
https://github.com/jg18/fs2open.github.com/tree/feature/sexp-containers-revised
...I noticed a TODO that is almost certainly a genuine bugfix. As such, it deserves its own PR. The line in question was last modified in 2012 by karajorma, and the bugfix should test for the special-arg in the entire actions tree rather than just the first action.
1) The ship-vanish SEXP (and script function) was already multiplayer-ready
2) The is-ship-visible SEXP was enhanced to add a second argument, which defaults to the player's ship in single-player mode
This is a follow-up to #2687. The final implementation of evaluateNumericSEXP different from the testing implementation in a small but crucial way that prevented it from actually working. Since it used `eval_num`, it didn't evaluate the specified SEXP node but rather the CAR (first element) of the node list. This fixes that by putting the node in a temporary SEXP list so that `eval_num` will look in the right place.
This refactors the tolower/toupper code to use standards-conformant logic, and also adds some helpful utility functions. Regular tolower/toupper must be supplied a value that can be represented as `unsigned char`, but the std:: functions are a bit more robust.
Implements send-message-chain as described in issue #3185. Also fixes the default argument for message priority, and mirrors the default argument fix to qtFRED.
One small detail that was overlooked in PR #3021... KeldorKatarn's old code used `strtod` while the new code used `stuff_float`. This wouldn't be a problem except that a couple MVP models use annoyingly formatted floats like 8.9e-08. So I decided to convert `stuff_float` to use `strtof` and do some more upgrades while I was at it.
For compatibility purposes some mods want alt names to truncate at the hash symbol. But we can't actually do that at mission load,
since we have to save them again in FRED. So this commit processes the names just before the mission starts.
To further complicate things, some mods actually want the hash to be displayed. So this commit introduces the double-hash as an escape sequence for a single hash.
* Can't simply use the previous fade_out color as the default, because of an edge-case with legacy usage. The refactor would disallow setting the fadout to black.
This is a follow-up to PR #2942. Given that the short-circuiting is now explicitly skipped for node trees containing the special argument, it should no longer be necessary to flush the conditional branch of the sexp tree. (The .cache field is already skipped for special-arg nodes.)
The sexp tree is still explicitly flushed for `every-time` and `every-time-argument`.
It takes a number as a maximum number of arguments that can be evaluated in a single call, but otherwise behaves very similarly to `any-of`; alternatively, if the number is 1, it's like an `in-sequence` that also skips arguments that don't satisfy the condition instead of just invalid ones.
Goober5000