Access control lists can permit read and write access to a file
but not permit to manipulate any attributes of the file. So it
is quite possible for futimens() to fail, just like chown() and
chmod() can fail, but this should be no cause for alarm: as long
as writing the backup file worked, then writing the file itself
will probably work too.
First, it is very unlikely that chmod() would fail as the user just
created the file herself. Second, even if chmod() would fail, this
is not a problem, because we have created the file with read+write
permissions for the owner only, so the file cannot accidentally be
left accessible to unintended others.
But most of all, such a failure should not stop nano from trying to
write the backup file. Only when the actual *writing* fails, should
we bother the user with a prompt.
If there are still systems where mkstemp() creates world-readable
temporary files, then please holler. On current BSDs and on GNU,
I've verified that mkstemp() creates files with 0600 permissions.
When deleting an existing backup file failed, we do not want to
append to this file, but want instead to overwrite it (when the
user has put 'set allow_insecure_backup' in their nanorc file).
Also, when using O_EXCL (in the normal, secure case), O_APPEND
is pointless, because the file will be created and thus empty.
This fixes https://savannah.gnu.org/bugs/?58439.
Bug existed since version 2.2.5, commit 461519cc.
A normal user can change the group of a file (if the user is a member
of that group), but cannot change the owner of that file. So, when a
user edits a file that belongs to a different user, the call of fchown()
will fail. But there is no harm in that. Also when the user is root,
there is no harm in fchown() failing -- it will simply mean that the
backup file will remain owned by root and will not be writable by the
intended owner (when root has the normal umask of 0022).
This fixes https://savannah.gnu.org/bugs/?58383.
Bug existed since version 2.2.5, commit 86be3af7.
In the past, when Speller and Linter and Formatter were all bound
to ^T (later ones taking priority), it was easier to exclude also
the formatter code when --disable-speller was used. But since the
formatter was reintroduced (in commit 34170611) and bound to its
own keystroke (M-F), this is no longer the case.
When, at a prompt, the user chose a function shortcut instead of typing
an answer, and this function printed some message to the status bar,
then we do not want to wipe this message. Also: the message overwrote
and cleared the prompt bar, so there is no need to wipe the latter.
This fixes https://savannah.gnu.org/bugs/?56273.
Bug existed since version 4.0, since justifying started giving feedback
(or rather since version 4.1, since M-J no longer crashed).
Commit 12cf1c99 added a beep() for every invalid keystroke at the
Yes-No prompt, but overlooked that KEY_WINCH is not invalid.
This fixes https://savannah.gnu.org/bugs/?58422.
Bug existed since version 4.8, commit 12cf1c99.
Commit b63c90bf avoided creating an empty buffer before asking the
yes-no question when encountering a lock file at startup, but the
SIGWINCH code still expected to have an open buffer whose contents
to show.
This fix also has the pleasant effect that, when resizing the screen
at the lock-file yes-no prompt, the title bar doesn't suddenly appear.
This fixes https://savannah.gnu.org/bugs/?58414.
Reported-by: Liu Hao <lh_mouse@126.com>
Bug existed since version 4.9, commit b63c90bf.
If unlinking would fail because the parent directory is unwritable,
then a check in has_valid_path() would have prevented do_lockfile()
from being called at all.
If in between the unlink() in delete_lockfile() and the fopen() in
write_lockfile() some other process creates a symlink in the place
of the lock file, then the fopen() could unexpectedly overwite a
root-owned file (when the user is root).
This basically reverts the previous commit, b4299f4f, but makes the
code a bit conciser.
One microsecond earlier, the lock file has been deleted (if it existed),
so, if between our unlink() and our open() some other process managed to
recreate the lock file... well, we want to delete it *again*. So, just
overwrite and truncate the lock file (if it exists).
When the lock file did NOT exist (a few microseconds earlier, when
checking in do_lockfile(), before calling write_lockfile()), then
the user expects the lock file to be written, so: just write it.
That between the check and the actual writing of the lock file there
is a small window of opportunity for other processes to write this
lock file is unfortunate, but it is not a reason to bother the user
with an error message when it happens.
One microsecond before a lock file is created an existing lock file
has been deleted, and if that deletion failed, writing the lock file
is aborted. So why should writing the lock file not be aborted when
the lock file cannot be exclusively created one microsecond later?
This makes no sense. So... always include the O_EXCL flag, also
when the INSECURE_BACKUP flag is set.
(And anyway: lock files are not an essential part of editing, they
are just a small service to the user, AND they have nothing to do
with backups, so a backup flag should not influence them.)
When two lines are joined, 'refresh_needed' is already set to TRUE,
so only when a midline character is deleted the check for a changed
number of chunks is needed.
Now all functions that are relevant only to softwrapping
get called only when softwrapping is on.
This also allows to elide an intermediate function call.
A file is always in either Unix or DOS or Mac format, and should
by default be saved again in that same format.
Any lone CRs or LFs after the first line should not change the
format that was deduced from that very first line.
Only when a CR is seen before any LF, and the CR is not followed
by a LF, should this CR be interpreted as a line separator. And
only then the file should be reported as being in Mac format --
as long as --noconvert is not used.
This fixes https://savannah.gnu.org/bugs/?58357.
Bug existed since at least version 2.0.6.
Also, when finish() is called when the user presses Cancel upon
encountering a lock file, there is no need to save any history
files because nothing has changed.
Benno Schulenberg