Prior to this fix, if job control is enabled but stdin is not a tty, we
would return an error from terminal_maybe_give_to_job which would cause us
to avoid waiting for the job. Instead just return notneeded.
Fixes#6573.
This updates the behavior of tilde to match the behavior found in vim.
In vim, tilde toggles the case of the character under the cursor and
advances one character. In visual mode, the case of each selected
character is toggled, the cursor position moves to the beginning of
the selection, and the mode is changed to normal. In fish, tilde
capitalizes the current letter and advances one word. There is no
current tilde command for visual mode in fish.
This patch adds the readline commands `togglecase-letter` and
`togglecase-selection` to match the behavior of vim more closely. The
only difference is that in visual mode, the cursor is not modified.
Modifying the cursor in visual mode would require either moving it in
`togglecase-selection`, which seems outside its scope or adding
something like a `move-to-selection-start` readline command.
We had previously added a more helpful error message when a literal zero
index was specified when indexing into an array. This patch extends that
coverage to cases indexing into a command substitution, e.g.
```fish
echo (printf "hello\nworld\n")[0]
```
Otherwise it would print "Unknown Signal" on Linux. I didn't see an
obvious way to check signal validity, plus it hardly matters.
Also mimic the output from BSD strsignal on Linux.
For `true`, this makes uses like the
: some description of the job &
we used to have impossible, also it's just *wrong* that true can
return something that isn't true.
For false it's not super important but it should generally be
symmetrical with true.
Fixes#6830
For some reason, with this change, typing "vi", Control-Z, and 2 x Control-D,
results in the cursor not moving correctly, but this only
seems to happen when starting fish from a fish that doesnt have this fix.
I hope that is a temporary glitch.
The prefix 'haha' is short enough, (and phonetic enough), that it could collide with an existing user on the system where the tests are running, causing the test to fail.
I kinda hate how fussy clang-format is. It reflows text
constantly (line limit), forces things onto one line *except* when
they're too long, and wants to turn this:
```c++
return true;;
```
into this:
```c++
return true;
;
```
instead of, you know, eliminating the second semicolon?
Anyway, it is what it is and we use it, I'll just look into getting some
more slack.
This allows code of the form `if jobs -q $some_pid` in scripts to check whether a previously started job is still running. Previously this would return the correct value, but also print an error message.
The invalid argument errors will still be printed.
Added test cases for both.
