From 935bf3f752b0f6d7643aa0ef789aac5afe66d1b0 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sun, 14 Jan 2018 13:27:20 -0800 Subject: filenamecat: make base a suffix of result * lib/filenamecat-lgpl.c (longest_relative_suffix): Remove. (mfile_name_concat): Always make BASE a suffix of the result, as cp expects this. To implement this, separate with '.' instead of '/' in some rare cases. Clarify spec to say ./BASE not BASE. * tests/test-filenamecat.c (main): Adjust tests to match current behavior. Check that BASE_IN_RESULT points to a copy of BASE and is a suffix of the resultk, and that DIR is a prefix of the result that is no longer than the prefix indicated by BASE_IN_RESULT. --- lib/filenamecat-lgpl.c | 57 +++++++++++++++++++++++++------------------------- 1 file changed, 28 insertions(+), 29 deletions(-) (limited to 'lib/filenamecat-lgpl.c') diff --git a/lib/filenamecat-lgpl.c b/lib/filenamecat-lgpl.c index 452d3b95df..f50ecc1382 100644 --- a/lib/filenamecat-lgpl.c +++ b/lib/filenamecat-lgpl.c @@ -31,55 +31,54 @@ # define mempcpy(D, S, N) ((void *) ((char *) memcpy (D, S, N) + (N))) #endif -/* Return the longest suffix of F that is a relative file name. - If it has no such suffix, return the empty string. */ - -static char const * _GL_ATTRIBUTE_PURE -longest_relative_suffix (char const *f) -{ - for (f += FILE_SYSTEM_PREFIX_LEN (f); ISSLASH (*f); f++) - continue; - return f; -} - -/* Concatenate two file name components, DIR and ABASE, in +/* Concatenate two file name components, DIR and BASE, in newly-allocated storage and return the result. The resulting file name F is such that the commands "ls F" and "(cd - DIR; ls BASE)" refer to the same file, where BASE is ABASE with any - file system prefixes and leading separators removed. - Arrange for a directory separator if necessary between DIR and BASE - in the result, removing any redundant separators. + DIR; ls ./BASE)" refer to the same file. If necessary, put + a separator between DIR and BASE in the result. Typically this + separator is "/", but in rare cases it might be ".". In any case, if BASE_IN_RESULT is non-NULL, set - *BASE_IN_RESULT to point to the copy of ABASE in the returned - concatenation. However, if ABASE begins with more than one slash, - set *BASE_IN_RESULT to point to the sole corresponding slash that - is copied into the result buffer. + *BASE_IN_RESULT to point to the copy of BASE at the end of the + returned concatenation. Return NULL if malloc fails. */ char * -mfile_name_concat (char const *dir, char const *abase, char **base_in_result) +mfile_name_concat (char const *dir, char const *base, char **base_in_result) { char const *dirbase = last_component (dir); size_t dirbaselen = base_len (dirbase); size_t dirlen = dirbase - dir + dirbaselen; - size_t needs_separator = (dirbaselen && ! ISSLASH (dirbase[dirbaselen - 1])); - - char const *base = longest_relative_suffix (abase); size_t baselen = strlen (base); - - char *p_concat = malloc (dirlen + needs_separator + baselen + 1); + char sep = '\0'; + if (dirbaselen) + { + /* DIR is not a file system root, so separate with / if needed. */ + if (! ISSLASH (dir[dirlen - 1]) && ! ISSLASH (*base)) + sep = '/'; + } + else if (ISSLASH (*base)) + { + /* DIR is a file system root and BASE begins with a slash, so + separate with ".". For example, if DIR is "/" and BASE is + "/foo" then return "/./foo", as "//foo" would be wrong on + some POSIX systems. A fancier algorithm could omit "." in + some cases but is not worth the trouble. */ + sep = '.'; + } + + char *p_concat = malloc (dirlen + (sep != '\0') + baselen + 1); char *p; if (p_concat == NULL) return NULL; p = mempcpy (p_concat, dir, dirlen); - *p = DIRECTORY_SEPARATOR; - p += needs_separator; + *p = sep; + p += sep != '\0'; if (base_in_result) - *base_in_result = p - IS_ABSOLUTE_FILE_NAME (abase); + *base_in_result = p; p = mempcpy (p, base, baselen); *p = '\0'; -- cgit v1.2.1