While ignoring permission errors from fchmod() and fchown() is okay
(since normal users are not always privileged to make such changes),
ignoring also more serious errors (like EIO) is not ideal.
Signed-off-by: Michalis Kokologiannakis <michalis@mpi-sws.org>
When there is just one match when <Tab> is pressed, and this match
is a directory, then a slash is added to 'shared', overwriting the
terminating NUL character. So, strcpy() cannot be used for copying
this 'shared' string, but strncpy() is needed, and the result needs
to be NUL terminated afterward.
This fixes https://savannah.gnu.org/bugs/?58826.
Bug existed since commit b0f56398 from eleven days ago.
Root has carte blanche to both read unreadable files and write
unwritable files -- the file system does not prevent this. So,
alert root when opening a file that is intended to be read-only.
This fulfills https://savannah.gnu.org/bugs/?58685.
Requested-by: Marius Bakke <mbakke@fastmail.com>
Rereading is unlikely to fail, but *if* it fails, maybe there is a
serious problem and the user wants to try and fix it before saving
the buffer and thus overwriting the original file.
After thinking about it, I don't like it that nano makes an unrequested
failsafe backup: in the vast, vast majority of cases it is a waste both
of time and of disk wear. If the user is worried about data loss, they
can use --backup. The fsync() after writing out the buffer (added in
commit a84cdaaa) already reduces the chances on data loss somewhat.
This change moves the code responsible for backup creation to a new,
separate function, backup_file(). This function returns a boolean
indicating whether saving the buffer should proceed or not.
Signed-off-by: Michalis Kokologiannakis <michalis@mpi-sws.org>
The file-saving procedure that nano followed was not crash-safe
under ext4 (and perhaps other filesystems) when editing existing
files. Specifically, modifying an existing file could lead to data
loss, since a modified file is not replaced atomically on disk.
Using "-B" did not ensure crash-safety either since the backup might
not have persisted on disk when the writeout of the file started.
In addition, if I/O pressure filled up the remaining disk space
after an existing file is truncated during save, nano would not
be able to finish saving the file, which would remain truncated.
This change addresses these issues by making nano do the following:
1) Make a temporary backup of the file being written so that there
is no time window such that (a) an existing file is truncated, and
(b) the buffer corresponding to said file has not been flushed to
disk. Such time windows are dangerous because, under certain
circumstances, they can lead to data loss on some filesystems.
The backup is made by copying the original file, and a second
attempt to HOME is made in case that first copy fails.
2) Use fsync() so that, when the save finishes, it is certain
that the file has been successfully written to disk.
This addresses https://savannah.gnu.org/bugs/?58642.
Signed-off-by: Michalis Kokologiannakis <michalis@mpi-sws.org>
Especially when it are just a handful of possible completions, it is
much nicer to have them listed close to the prompt bar where the eyes
of the user are.
This fulfills https://savannah.gnu.org/bugs/?58620.
This gives quicker feedback, and spares the user unnecessary beeps
and typing. Also, now a beep after a <Tab> means just one thing:
there are NO completions.
This fulfills https://savannah.gnu.org/bugs/?58627.
The parameter was referenced in just one place. So, simply check for
the three relevant menus (and unrestricted mode) and be done with it.
This also has the pleasant effect that the menu name is now the first
parameter of do_prompt(), thus clearly indicating what prompt it is,
instead of having an opaque TRUE or FALSE value at the beginning.
Tabbing can list all files in the given directory, but restricted mode
is supposed to prevent the user from any access to the filesystem...
This fixes https://savannah.gnu.org/bugs/?58632.
Bug existed (in this form) since version 1.3.4, commit f7b5d930.
Instead of burdening seven other calls of do_prompt() with a useless
parameter, just check for MGOTODIR in the appropriate place. It also
saves having to pass the parameter down through three more functions.
The single dot serves no purpose, as the user is already there. And
the double dot is reached more easily by typing a second dot first.
And anyway, . and .. are not shown when the user does not type a dot
first, so why show them when the user types a single dot followed by
<Tab><Tab>? Most likely the user wants to see actual dot files, so
just show those.
This fixes https://savannah.gnu.org/bugs/?58619.
