Directly access the job list without the intermediate job_iterator_t,
and remove functions that are ripe for abuse by modifying a local
enumeration of the same list instead of operating on the iterators
directly (e.g. proc.cpp iterates jobs, and mid-iteration calls
parser::job_remove(j) with the job (and not the iterator to the job),
causing an invisible invalidation of the pre-existing local iterators.
This printed weird things like
```fish
$ functions -x
functions: Unknown option '-x'
(Type 'help functions' for related documentation)
```
Instead, let's make it
```fish
$ functions -x
functions: Unknown option '-x'
(Type 'help functions' for related documentation)
```
This was printed basically everywhere.
The user knows what they executed on standard input.
A good example:
```fish
set c (subme 513)
```
used to print
```
fish: Too much data emitted by command substitution so it was discarded
set -l x (string repeat -n $argv x)
^
in function 'subme'
called on standard input
with parameter list '513'
in command substitution
called on standard input
```
and now it is
```
fish: Too much data emitted by command substitution so it was discarded
set -l x (string repeat -n $argv x)
^
in function 'subme' with arguments '513'
in command substitution
```
See #5434.
Now:
```
cd: Unknown option '-r'
~/dev/fish-shell/share/functions/cd.fish (line 40):
builtin cd $argv
^
in function 'cd' with arguments '-r'
in function 'f'
in function 'd'
in function 'b' with arguments '-1q --wurst'
in function 'a'
called on standard input
```
See #5434.
This printed things like
```
in function 'f'
called on standard input
in function 'd'
called on standard input
in function 'b'
called on standard input
in function 'a'
called on standard input
```
As a first step, it removes the empty lines so it's now
```
in function 'f'
called on standard input
in function 'd'
called on standard input
in function 'b'
called on standard input
in function 'a'
called on standard input
```
See #5434.
This switches env_var_t to be an immutable value type, and stores its
contents via a shared_ptr. This eliminates string copying when fetching
env_var_t values.
If a function process is deferred, allow it to be unbuffered.
This permits certain simple cases where functions are piped to external
commands to execute without buffering.
This is a somewhat-hacky stopgap measure that can't really be extended
to more general concurrent processes. However it is overall an improvement
in user experience that might help flush out some bugs too.
In a job, a deferred process is the last fish internal process which pipes
to an external command. Execute the deferred process last; this will allow
for streaming its output.
I believe this was selected to be artificially low for the sake
of it displaying well in prompts. But people should expect to get
the same output as can be gotten from `hostname`.
Fixes#5758
The code already allowed for variable width (multicell) *display* of the
newline omitted character, but there was no way to define it as being
more than one `wchar_t`.
This lets us use a string on console sessions (^J aka newline feed)
instead of an ambiguous character like `@` (used in some versions of
vim for ^M) or `~` (what we were using).
