Paul Eggert 71fd20c222 diff: prefer openat+fstat more often ...

This closes some more races, by using openat+fstat instead
of fstatat+openat which can get confused by some other process
renaming files in the meantime.  Not all races are closed of course.
* bootstrap.conf (gnulib_modules): Add d-type.
* src/diff.c (errno_encode, errno_decode): Remove, as file
descriptors are no longer portmanteau variables.  All uses removed.
(detype_from_mode): New function.
(dir_p): Use detype, not stat.st_mode.
(compare_files): New args DETYPE0 and DETYPE1.  All uses changed.
Update detype and err as new info arrives.
Adjust to desc's new use (no longer encodes errno).
Do not ignore lseek failures on regular files.
Prefer openat+fstat to fstatat+openat when detype shows that it's safe,
and avoid both fstat and fstatat if detype suffices.
Use ‘error’ with errno value rather than setting error
and then calling perror_with_name.  Coalesce two of these
error diagnostics into one by moving an error check before
the diagnostic is output.  Coalesce two calls to diff_dirs.
Print file type based on detype if available,
in case neither fstat nor fstatat was called.
* src/diff.h (enum detype): New type.
(struct file_data): New slots err, detype.
(NONEXISTENT, UNOPENED): Renumber so that -1 stands for open failed.
* src/dir.c (HAVE_STRUCT_DIRENT_D_TYPE): Default to false.
(dir_read): Return to caller the d_type, if available.
 	(diff_dirs): Pass detype to compare_files.

2023-08-05 11:01:41 -07:00

..

diagmeet.note

maint: quote 'like this' or "like this", not `like this'

2012-01-25 23:54:38 -08:00

diffutils.texi

diff: prefer openat+fstat more often

2023-08-05 11:01:41 -07:00

fdl.texi

maint: update copyright dates

2023-01-01 17:19:37 -08:00

Makefile.am

build: Ensure that makeinfo ≥ 6.8 checks the @menu structure

2023-06-24 17:52:51 -07:00