Don't mmap history files on remote file systems
This merges some changes to history that may help to mitigate the crashes seen in #5088 . These SIGBUS crashes occur when reading a memory mapping whose underlying file was truncated. It's not clear why this should occur more often on NFS (or ever). However memory mapping over NFS is sketchy anyways so this is desirable regardless.
Migrate the mmap() logic into a new class history_file_contents_t which
will serve to encapsulate conditional logic if we choose to use read()
instead of mmap().
This adds a new string command split0, which splits on zero bytes.
split0 has superpowers because its output is not further split on
newlines when used in command substitutions.
separated_buffer_t encapsulates the logic around discarding (which
was previously duplicated between output_stream_t and io_buffer_t),
and will also encapsulate the logic around explicitly separated
output.
If just one of the range ends is negative, this now forces direction away from it.
I.e. if the beginning is negative, we go in reverse.
If the end is negative, we go forwards.
This fixes cases like
$var[2..-1]
if $var only has one element.
While supported by gcc and clang, \e is a gcc-specific extension and not
formally defined in the C or C++ standards.
See [0] for a list of valid escapes.
[0]: https://stackoverflow.com/a/10220539/17027
We've tried numerous approaches to mitigate the race condition between
`posix_spawn` and the `setpgid` call, but unfortunately due to the flags
we pass to `posix_spawn`, it (rarely? never?) results in `vfork()` being
used, which means it is never executed atomically. Since it is executed
out-of-band, we must manually call `setpgid` in case `posix_spawn`
hasn't gotten around to doing that yet, but in the event that it has, an
EACCES error can be returned.
Closes#4884. Closes#4715. See also #4778.
On systems where the terminfo for TERM does not contain a string for
attributes such as enter_underline_mode, etc. fish was crashing with a
fatal error message and a note to email the developers.
These are non-essential text attribute changes and should not trigger
such a failure.
[9/13] Building CXX object CMakeFiles/fishlib.dir/src/builtin_string.cpp.o
../src/builtin_string.cpp:1221:12: warning: mangled name of 'string_transform' will change in C++17 due to non-throwing exception specification in function signature [-Wc++17-compat-mangling]
static int string_transform(parser_t &parser, io_streams_t &streams, int argc, wchar_t **argv, decltype(std::towlower) func) {
^
1 warning generated.
Our completion machinery calls our `__fish_describe_command` function
to describe commands via apropos. Only it trusts the output a bit too
much, so it crashes when any line from that is shorter than the
original string.
Fix this by skipping any string that is shorter than the original,
since it can't be a match anyway.
Also stop doing wcslen so often - std::strings are nice!
Fixes#5014.
There really is no need to
- Timeout just because the _first_ character was a control character
- Timeout because of any control character other than escape
The reason to timeout because the '\e' sequence can appear by itself (signifying
pressing the escape key) and still make
sense - e.g. vi-mode has it bound to a rather important function!
But a \c can't appear by itself, so we can just block.
This allows binding sequences like \cx\ce and inputting them at a
leisurely pace rather than the frantic escape_timeout one.
It should also improve sequences that _include_ escape somewhere else.
E.g. something like a\eb ("a, then alt+b") should now time out for the "\eb" part,
allowing users to bind a\e ("a, then escape") to something else. Why you'd want to do
that, I have no idea. But it's more consistent, and that's nice!
For regex-mode, this should be enough to read NUL-delimited strings to act on, but not
quite patterns and replacements.
Glob-mode requires more work - it uses wcscmp internally, which is unsuitable.
Also the various styles have one function each with barely any
difference - mostly passing the corresponding STYLE argument.
Pack them into one function for escape and one for unescape to save
about 100 lines.
We're now actually handling wchar_t here, so comparing the 0x80 bit
would break for UTF-16, causing ASCII false-positives.
Also simplifies a bit, since we no longer need a second variable.
printf 'a\0b' | string length
used to print "1". Now it prints "3".
Note that this switches to using C++'s std::string::length, which
might give differing results.
