From 7fa1641db049912f59654153d077953714720ca2 Mon Sep 17 00:00:00 2001 From: Pádraig Brady Date: Fri, 17 Jan 2014 03:54:29 +0000 Subject: ln: fix replacing symbolic links whose targets can't exist * src/ln.c (errno_nonexisting): A new function to determine if the errno implies that a file doesn't or can't (currently) exist. (target_directory_operand): Use the new function to expand the set of errors we handle. * tests/ln/sf-1.sh: Add test cases for the newly handled errors. * THANKS.in: Mention the reporter. * NEWS: Mention the bug fix. --- NEWS | 4 ++++ THANKS.in | 1 + src/ln.c | 14 ++++++++++++-- tests/ln/sf-1.sh | 17 ++++++++++++++++- 4 files changed, 33 insertions(+), 3 deletions(-) diff --git a/NEWS b/NEWS index 699a7d3a1..88a41547e 100644 --- a/NEWS +++ b/NEWS @@ -14,6 +14,10 @@ GNU coreutils NEWS -*- outline -*- when reading the SELinux context for a file. [bug introduced in coreutils-8.22] + ln -sf now replaces symbolic links whose targets can't exist. Previously + it would display an error, requiring --no-dereference to avoid the issue. + [bug introduced in coreutils-5.3.0] + * Noteworthy changes in release 8.22 (2013-12-13) [stable] diff --git a/THANKS.in b/THANKS.in index 5b3e96ed2..fb7d6e084 100644 --- a/THANKS.in +++ b/THANKS.in @@ -341,6 +341,7 @@ Kaveh R. Ghazi ghazi@caip.rutgers.edu Keith M. Briggs keith.briggs@bt.com Keith Owens kaos@audio.apana.org.au Keith Thompson kst@cts.com +Ken Irving ken.irving@alaska.edu Ken Pizzini kenp@halcyon.com Kevin Mudrick kmudrick@healthmarketscience.com Kirk Kelsey kirk.kelsey@0x4b.net diff --git a/src/ln.c b/src/ln.c index b4903620b..aab9cf2fa 100644 --- a/src/ln.c +++ b/src/ln.c @@ -103,8 +103,18 @@ static struct option const long_options[] = {NULL, 0, NULL, 0} }; +/* Return true when the passed ERR implies + that a file does not or could not exist. */ + +static bool +errno_nonexisting (int err) +{ + return err == ENOENT || err == ENAMETOOLONG || err == ENOTDIR || err == ELOOP; +} + + /* FILE is the last operand of this command. Return true if FILE is a - directory. But report an error there is a problem accessing FILE, + directory. But report an error if there is a problem accessing FILE, or if FILE does not exist but would have to refer to an existing directory if it referred to anything at all. */ @@ -119,7 +129,7 @@ target_directory_operand (char const *file) (dereference_dest_dir_symlinks ? stat (file, &st) : lstat (file, &st)); int err = (stat_result == 0 ? 0 : errno); bool is_a_dir = !err && S_ISDIR (st.st_mode); - if (err && err != ENOENT) + if (err && ! errno_nonexisting (errno)) error (EXIT_FAILURE, err, _("failed to access %s"), quote (file)); if (is_a_dir < looks_like_a_dir) error (EXIT_FAILURE, err, _("target %s is not a directory"), quote (file)); diff --git a/tests/ln/sf-1.sh b/tests/ln/sf-1.sh index 3f4f8f1ae..17e67a9fb 100755 --- a/tests/ln/sf-1.sh +++ b/tests/ln/sf-1.sh @@ -20,12 +20,27 @@ print_ver_ ln echo foo > a || framework_failure_ -ln -s . b || framework_failure_ +# Check that a target directory of '.' is supported +# and that indirectly specifying the same target and link name +# through that is detected. +ln -s . b || framework_failure_ ln -sf a b > err 2>&1 && fail=1 case $(cat err) in *'are the same file') ;; *) fail=1 ;; esac +# Ensure we replace symlinks that don't or can't link to an existing target. +# coreutils-8.22 would fail to replace {ENOTDIR,ELOOP,ENAMETOOLONG}_link below. +name_max_plus1=$(expr $(stat -f -c %l .) + 1) +test $name_max_plus1 -gt 1 || skip_ 'Error determining NAME_MAX' +long_name=$(printf '%0*d' $name_max_plus1 0) +for f in '' f; do + ln -s$f missing ENOENT_link || fail=1 + ln -s$f a/b ENOTDIR_link || fail=1 + ln -s$f ELOOP_link ELOOP_link || fail=1 + ln -s$f "$long_name" ENAMETOOLONG_link || fail=1 +done + Exit $fail -- cgit v1.2.3-54-g00ecf