Let's hope this doesn't causes build failures for e.g. musl: I just
know it's good on macOS and our Linux CI.
It's been a long time.
One fix this brings, is I discovered we #include assert.h or cassert
in a lot of places. If those ever happen to be in a file that doesn't
include common.h, or we are before common.h gets included, we're
unawaringly working with the system 'assert' macro again, which
may get disabled for debug builds or at least has different
behavior on crash. We undef 'assert' and redefine it in common.h.
Those were all eliminated, except in one catch-22 spot for
maybe.h: it can't include common.h. A fix might be to
make a fish_assert.h that *usually* common.h exports.
Finish the transition to termsize.h. Remove the scary termsize bits
from common.cpp, which can throw off events at arbitrary calls and are
dangerously reentrant. Migrate everyone to the new termsize.h.
fish's handling of terminal sizes is currently rather twisted. The
essential problem is that the terminal size may change at any point from a
SIGWINCH, and common_get_{width,height} may modify it and post variable
change events from arbitrary locations.
Tighten up the semantics. Assign responsibility for managing the tty size
to a new class, `termsize_container_t`. Rationalize locking and reentrancy.
Explicitly nail down the relationship between $COLUMNS/$LINES and the tty
size. The new semantics are: whatever changed most recently takes
precendence.
