Mercurial > hg > octave-nkf > gnulib-hg
changeset 9227:484ada1ccebf
canonicalize: Avoid a false-positive cycle failure.
* modules/canonicalize (Depends-on): Add file-set and hash-triple. Sort.
Remove cycle-check.
* lib/canonicalize.c: Include file-set.h and hash-triple.h, not cycle-check.h.
(seen_triple): New function.
(canonicalize_filename_mode): Use it instead of cycle-check.
* tests/test-canonicalize.c: Add a test for this bug.
* tests/test-canonicalize.sh: Set up and run the test.
author | Jim Meyering <jim@meyering.net> |
---|---|
date | Mon, 24 Sep 2007 13:39:37 +0200 |
parents | b7de93942166 |
children | 49d7e37d9558 |
files | ChangeLog lib/canonicalize.c modules/canonicalize tests/test-canonicalize.c tests/test-canonicalize.sh |
diffstat | 5 files changed, 74 insertions(+), 6 deletions(-) [+] |
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line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,15 @@ 2007-09-27 Jim Meyering <jim@meyering.net> + canonicalize: Avoid a false-positive cycle failure. + * modules/canonicalize (Depends-on): Add file-set and hash-triple. + Sort. Remove cycle-check. + * lib/canonicalize.c: Include file-set.h and hash-triple.h, + not cycle-check.h. + (seen_triple): New function. + (canonicalize_filename_mode): Use it instead of cycle-check. + * tests/test-canonicalize.c: Add a test for this bug. + * tests/test-canonicalize.sh: Set up and run the test. + New module, file-set. * modules/file-set: Define it. * lib/file-set.c, lib/file-set.h: Implement.
--- a/lib/canonicalize.c +++ b/lib/canonicalize.c @@ -34,8 +34,9 @@ #include <errno.h> #include <stddef.h> -#include "cycle-check.h" +#include "file-set.h" #include "filenamecat.h" +#include "hash-triple.h" #include "xalloc.h" #include "xgetcwd.h" @@ -123,6 +124,30 @@ } #endif /* !HAVE_CANONICALIZE_FILE_NAME */ +/* Return true if we've already seen the triple, <FILENAME, dev, ino>. + If *HT is not initialized, initialize it. */ +static bool +seen_triple (Hash_table **ht, char const *filename, struct stat const *st) +{ + if (*ht == NULL) + { + size_t initial_capacity = 7; + *ht = hash_initialize (initial_capacity, + NULL, + triple_hash, + triple_compare, + triple_free); + if (*ht == NULL) + xalloc_die (); + } + + if (seen_file (*ht, filename, st)) + return true; + + record_file (*ht, filename, st); + return false; +} + /* Return the canonical absolute name of file NAME. A canonical name does not contain any `.', `..' components nor any repeated file name separators ('/') or symlinks. Whether components must exist @@ -136,7 +161,7 @@ char const *end; char const *rname_limit; size_t extra_len = 0; - struct cycle_check_state cycle_state; + Hash_table *ht = NULL; if (name == NULL) { @@ -176,7 +201,6 @@ dest = rname + 1; } - cycle_check_init (&cycle_state); for (start = end = name; *start; start = end) { /* Skip sequence of multiple file name separators. */ @@ -237,7 +261,11 @@ char *buf; size_t n, len; - if (cycle_check (&cycle_state, &st)) + /* Detect loops. We cannot use the cycle-check module here, + since it's actually possible to encounter the same symlink + more than once in a given traversal. However, encountering + the same symlink,NAME pair twice does indicate a loop. */ + if (seen_triple (&ht, name, &st)) { __set_errno (ELOOP); if (can_mode == CAN_MISSING) @@ -298,10 +326,14 @@ *dest = '\0'; free (extra_buf); + if (ht) + hash_free (ht); return rname; error: free (extra_buf); free (rname); + if (ht) + hash_free (ht); return NULL; }
--- a/modules/canonicalize +++ b/modules/canonicalize @@ -8,12 +8,13 @@ m4/canonicalize.m4 Depends-on: -cycle-check +areadlink-with-size +file-set filenamecat +hash-triple sys_stat xalloc xgetcwd -areadlink-with-size configure.ac: AC_FUNC_CANONICALIZE_FILE_NAME
--- a/tests/test-canonicalize.c +++ b/tests/test-canonicalize.c @@ -127,5 +127,17 @@ free (result2); } + /* Ensure that the following is resolved properly. + Before 2007-09-27, it would mistakenly report a loop. */ + { + char *result1 = canonicalize_filename_mode ("t-can.tmp", CAN_EXISTING); + char *result2 = canonicalize_filename_mode ("t-can.tmp/p/1", CAN_EXISTING); + ASSERT (result1 != NULL); + ASSERT (result2 != NULL); + ASSERT (strcmp (result2 + strlen (result1), "/d/2") == 0); + free (result1); + free (result2); + } + return 0; }
--- a/tests/test-canonicalize.sh +++ b/tests/test-canonicalize.sh @@ -20,6 +20,19 @@ && mkdir lum ) || exit 1 +# Trigger a bug that would make the function mistakenly report a loop. +# To trigger it, we have to construct a name/situation during the +# resolution of which the code dereferences the same symlink (S) +# two different times with no actual loop. In addition, the +# second and fourth calls to readlink must operate on S. +(cd t-can.tmp \ + && ln -s s p \ + && ln -s d s \ + && mkdir d \ + && echo > d/2 \ + && ln -s ../s/2 d/1 +) || exit 1 + ./test-canonicalize${EXEEXT} result=$?