Rewrite diskio function so as not to assume any particular cwd

* src/backup.c (get_backup_suffix)
(find_backup_file_name): Get directory descriptor as first argument.
* src/diskio.c: Rewrite using *at() functions.
* src/gpg.c (rmdir_r): Silently skip ENOENT.
(verify_detached_signature): push_dir/pop_dir.
* src/triplet.c: Don't change to spool->source_dir.  Underlying
functions don't assume any specific cwd.
* src/wydawca.h (find_backup_file_name)
(create_hierarchy): Change signatures. All uses changed.

* tests/Makefile.am: Add new tests.
* tests/testsuite.at: Likewise.
(AT_WYDAWCA_DAEMON): Take additional argument.
* tests/inotify-rmsymlink.at: New test.
* tests/inotify-symlink.at: New test.
* tests/rmsymlink00.at: New test.
* tests/symlink00.at: New test.
* tests/symlink01.at: New test.
* tests/dist/rmsymlink.directive.asc: New directive file.
* tests/dist/symlink.directive.asc: New directive file.

1 files changed, 12 insertions, 15 deletions

diff --git a/src/backup.c b/src/backup.c
index 8f94e88..f4ab994 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -41,11 +41,10 @@ split_filename(char const *file, char **pdir)
 #define ISDIGIT(c) ('0' <= (c) && (c) <= '9')
 
 static char *
-get_backup_suffix(char const *file, enum backup_type type)
+get_backup_suffix(int dirfd, char const *file, enum backup_type type)
 {
-    char *dirname;
-    const char *basename;
     size_t baselen;
+    int fd;
     DIR *dir;
     struct dirent *ent;
     char *lastsuf = NULL;
@@ -58,22 +57,21 @@ get_backup_suffix(char const *file, enum backup_type type)
     if (type == simple_backups)
 	return grecs_strdup(simple_backup_suffix);
 
-    basename = split_filename(file, &dirname);
-    baselen = strlen(basename);
-    dir = opendir(dirname);
-    if (!dir) {
-	int ec = errno;
-	free(dirname);
-	errno = ec;
+    baselen = strlen(file);
+    fd = openat(dirfd, ".", O_RDONLY | O_NONBLOCK | O_DIRECTORY);
+    if (fd == -1)
+	return NULL;
+    
+    dir = fdopendir(fd);
+    if (!dir)
 	return NULL;
-    }
 
     while ((ent = readdir(dir))) {
 	size_t len = strlen(ent->d_name);
 	const char *p;
 	size_t suflen;
 
-	if (len < baselen + 4 || memcmp(ent->d_name, basename, baselen))
+	if (len < baselen + 4 || memcmp(ent->d_name, file, baselen))
 	    continue;
 	p = ent->d_name + baselen;
 	suflen = len - baselen;
@@ -104,7 +102,6 @@ get_backup_suffix(char const *file, enum backup_type type)
 	}
     }
     closedir(dir);
-    free(dirname);
 
     if (lastsuf) {
 	size_t newsuflen;
@@ -130,7 +127,7 @@ get_backup_suffix(char const *file, enum backup_type type)
 }
 
 char *
-find_backup_file_name(char const *file, enum backup_type type)
+find_backup_file_name(int dirfd, char const *file, enum backup_type type)
 {
     size_t flen;
     char *suffix;
@@ -141,7 +138,7 @@ find_backup_file_name(char const *file, enum backup_type type)
 	return NULL;
     }
 
-    suffix = get_backup_suffix(file, type);
+    suffix = get_backup_suffix(dirfd, file, type);
     if (!suffix)
 	return NULL;
     flen = strlen(file);