Problem
- `redir_exec` is obsolete, but it keeps getting used in new tests
because people copy existing tests.
- Disadvantages of `redir_exec`:
- Captures extra junk before the actual error/message that we _want_ to test.
- Does not fail on error, unlike e.g. `command()`.
Solution
- Use new functions like `nvim_exec` and `pcall_err`.
After cbc8d72fde when editing
the command in the command editing window (q:, q/, q?) it was possible
to switch to the previous tab. Doing so put Nvim in a bad state.
Moreover, switching tabs via the other available mechanisms (gt, gT,
<C-W>gt, <C-W>gT) is not possible when in the command editing window.
Here, the behavior is prevented. It is no longer possible to switch to
the previous tab when editing the command in the command editing window.
The solution is to share code between gt, gT, and g<Tab>. Specifically,
goto_tabpage_lastused now calls through goto_tabpage rather than
directly calling goto_tabpage_tp. Doing so works well because all the
validation enjoyed by gt and gT is present in goto_tabpage.
In a multi-window scenario, it is possible to return focus to the last
accessed window via n_CTRL-W_p. However, in the case of a multi-tab
scenario, there was previously no way to return focus to the last
accessed *tab*. Here, that ability is added via n_g<tab>.
Additionally, the index of the previous tab is exposed via
tabpagenr('#'), mirroring the existing functionality of winnr('#').
Implement nvim_command_output with `execute({cmd},"silent")`.
Behavior changes:
- does not provoke any hit-enter prompt
- no longer prepends a newline char
- does not capture some noise (like the "[New File]" message, see the
change to tabnewentered_spec.lua)
Technically ("bug-for-bug") this a breaking change. But the previous
behavior of nvim_command_output meant that it probably wasn't used for
anything outside of tests.
Also remove the undocumented `v:command_output` variable which was
a hack introduced only for the purposes of nvim_command_output.
closes#7726
It is otherwise impossible to determine which test failed sanitizer/valgrind
check. test/functional/helpers.lua module return was changed so that tests which
do not provide after_each function to get new check will automatically fail.
