Closes#5291
Restores behaviour identical to Vim. If the user calls the VimScript
function 'getcwd()' and the working directory cannot be found (for
example because the directory has been deleted since the last time it
was used) an empty string needs to be returned instead of throwing an
error.
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.
The directories table contains the names of the expected directory names
for varying scopes of the :cd tests. Using named indexes, instead of
numbered, makes the test more readable.
Build wcwd/tcwd and wlwd/tlwd on top of the reworked cwd/lwd functions.
This will allow for easier testing of `getcwd()`/`haslocaldir()` in
arbitrary windows and/or tab pages.
While trying to debug an issue, I discovered that the tests for illegal
arguments depended on the prior suite having run and started a session.
Let's remove that unintentional dependency by starting our own session
before each test.
New ex commands: 'tcd', 'tchdir'
Changed Vimscript functions: 'haslocaldir', 'getcwd'
The ex-commands ':tcd' and ':tchdir' are the tab-local equivalents of
':lcd' and ':lchdir'. There are no new Vimscript functions introduced,
instead the functions 'haslocaldir' and 'getcwd' take in optional
arguments. See the documentation for details
Since there is now different levels of local directory a simple boolean
at source level is no longer sufficient; a new enumeration type is used
for the scope-level from now on.
The documentation has been accommodated for these new commands and
functional tests have been written to test the feature.
