tree-wide: drop NULL sentinel from strjoin

This makes strjoin and strjoina more similar and avoids the useless final
argument.

spatch -I . -I ./src -I ./src/basic -I ./src/basic -I ./src/shared -I ./src/shared -I ./src/network -I ./src/locale -I ./src/login -I ./src/journal -I ./src/journal -I ./src/timedate -I ./src/timesync -I ./src/nspawn -I ./src/resolve -I ./src/resolve -I ./src/systemd -I ./src/core -I ./src/core -I ./src/libudev -I ./src/udev -I ./src/udev/net -I ./src/udev -I ./src/libsystemd/sd-bus -I ./src/libsystemd/sd-event -I ./src/libsystemd/sd-login -I ./src/libsystemd/sd-netlink -I ./src/libsystemd/sd-network -I ./src/libsystemd/sd-hwdb -I ./src/libsystemd/sd-device -I ./src/libsystemd/sd-id128 -I ./src/libsystemd-network --sp-file coccinelle/strjoin.cocci --in-place $(git ls-files src/*.c)

git grep -e '\bstrjoin\b.*NULL' -l|xargs sed -i -r 's/strjoin\((.*), NULL\)/strjoin(\1)/'

This might have missed a few cases (spatch has a really hard time dealing
with _cleanup_ macros), but that's no big issue, they can always be fixed
later.

12 files changed, 29 insertions, 30 deletions

diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c
index 359d85f2e8..656bb13719 100644
--- a/src/basic/btrfs-util.c
+++ b/src/basic/btrfs-util.c
@@ -1642,7 +1642,7 @@ static int subvol_snapshot_children(int old_fd, int new_fd, const char *subvolum
                         if (old_child_fd < 0)
                                 return -errno;
 
-                        np = strjoin(subvolume, "/", ino_args.name, NULL);
+                        np = strjoin(subvolume, "/", ino_args.name);
                         if (!np)
                                 return -ENOMEM;
 
diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index cede835920..5fce32f769 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -345,7 +345,7 @@ int cg_kill_recursive(
         while ((r = cg_read_subgroup(d, &fn)) > 0) {
                 _cleanup_free_ char *p = NULL;
 
-                p = strjoin(path, "/", fn, NULL);
+                p = strjoin(path, "/", fn);
                 free(fn);
                 if (!p)
                         return -ENOMEM;
@@ -479,7 +479,7 @@ int cg_migrate_recursive(
         while ((r = cg_read_subgroup(d, &fn)) > 0) {
                 _cleanup_free_ char *p = NULL;
 
-                p = strjoin(pfrom, "/", fn, NULL);
+                p = strjoin(pfrom, "/", fn);
                 free(fn);
                 if (!p)
                         return -ENOMEM;
@@ -562,11 +562,11 @@ static int join_path_legacy(const char *controller, const char *path, const char
         if (isempty(path) && isempty(suffix))
                 t = strappend("/sys/fs/cgroup/", dn);
         else if (isempty(path))
-                t = strjoin("/sys/fs/cgroup/", dn, "/", suffix, NULL);
+                t = strjoin("/sys/fs/cgroup/", dn, "/", suffix);
         else if (isempty(suffix))
-                t = strjoin("/sys/fs/cgroup/", dn, "/", path, NULL);
+                t = strjoin("/sys/fs/cgroup/", dn, "/", path);
         else
-                t = strjoin("/sys/fs/cgroup/", dn, "/", path, "/", suffix, NULL);
+                t = strjoin("/sys/fs/cgroup/", dn, "/", path, "/", suffix);
         if (!t)
                 return -ENOMEM;
 
@@ -586,7 +586,7 @@ static int join_path_unified(const char *path, const char *suffix, char **fs) {
         else if (isempty(suffix))
                 t = strappend("/sys/fs/cgroup/", path);
         else
-                t = strjoin("/sys/fs/cgroup/", path, "/", suffix, NULL);
+                t = strjoin("/sys/fs/cgroup/", path, "/", suffix);
         if (!t)
                 return -ENOMEM;
 
@@ -613,7 +613,7 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
                 else if (!path)
                         t = strdup(suffix);
                 else
-                        t = strjoin(path, "/", suffix, NULL);
+                        t = strjoin(path, "/", suffix);
                 if (!t)
                         return -ENOMEM;
 
@@ -1145,7 +1145,7 @@ int cg_is_empty_recursive(const char *controller, const char *path) {
                 while ((r = cg_read_subgroup(d, &fn)) > 0) {
                         _cleanup_free_ char *p = NULL;
 
-                        p = strjoin(path, "/", fn, NULL);
+                        p = strjoin(path, "/", fn);
                         free(fn);
                         if (!p)
                                 return -ENOMEM;
diff --git a/src/basic/conf-files.c b/src/basic/conf-files.c
index c781610e14..c0c22610d7 100644
--- a/src/basic/conf-files.c
+++ b/src/basic/conf-files.c
@@ -60,7 +60,7 @@ static int files_add(Hashmap *h, const char *root, const char *path, const char
                 if (!dirent_is_file_with_suffix(de, suffix))
                         continue;
 
-                p = strjoin(dirpath, "/", de->d_name, NULL);
+                p = strjoin(dirpath, "/", de->d_name);
                 if (!p)
                         return -ENOMEM;
 
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 1cfb7a98f5..1615456659 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -676,7 +676,7 @@ static int load_env_file_push(
                 return -EINVAL;
         }
 
-        p = strjoin(key, "=", strempty(value), NULL);
+        p = strjoin(key, "=", strempty(value));
         if (!p)
                 return -ENOMEM;
 
@@ -963,9 +963,9 @@ static int search_and_fopen_internal(const char *path, const char *mode, const c
                 FILE *f;
 
                 if (root)
-                        p = strjoin(root, *i, "/", path, NULL);
+                        p = strjoin(root, *i, "/", path);
                 else
-                        p = strjoin(*i, "/", path, NULL);
+                        p = strjoin(*i, "/", path);
                 if (!p)
                         return -ENOMEM;
 
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index 48952a1c26..d2c322a0de 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -742,7 +742,7 @@ int chase_symlinks(const char *path, const char *_root, char **ret) {
                                 /* A relative destination. If so, this is what we'll prefix what's left to do with what
                                  * we just read, and start the loop again, but remain in the current directory. */
 
-                                joined = strjoin("/", destination, todo, NULL);
+                                joined = strjoin("/", destination, todo);
                                 if (!joined)
                                         return -ENOMEM;
 
diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c
index 0ef00676ef..b221309a4d 100644
--- a/src/basic/mount-util.c
+++ b/src/basic/mount-util.c
@@ -641,7 +641,7 @@ static char* mount_flags_to_string(long unsigned flags) {
                     FLAG(MS_I_VERSION),
                     FLAG(MS_STRICTATIME),
                     FLAG(MS_LAZYTIME),
-                    y, NULL);
+                    y);
         if (!x)
                 return NULL;
         if (!y)
diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 0f5b20cf05..e438f27df5 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -83,7 +83,7 @@ char *path_make_absolute(const char *p, const char *prefix) {
         if (path_is_absolute(p) || !prefix)
                 return strdup(p);
 
-        return strjoin(prefix, "/", p, NULL);
+        return strjoin(prefix, "/", p);
 }
 
 int path_make_absolute_cwd(const char *p, char **ret) {
@@ -104,7 +104,7 @@ int path_make_absolute_cwd(const char *p, char **ret) {
                 if (!cwd)
                         return negative_errno();
 
-                c = strjoin(cwd, "/", p, NULL);
+                c = strjoin(cwd, "/", p);
         }
         if (!c)
                 return -ENOMEM;
@@ -444,13 +444,11 @@ char* path_join(const char *root, const char *path, const char *rest) {
                 return strjoin(root, endswith(root, "/") ? "" : "/",
                                path[0] == '/' ? path+1 : path,
                                rest ? (endswith(path, "/") ? "" : "/") : NULL,
-                               rest && rest[0] == '/' ? rest+1 : rest,
-                               NULL);
+                               rest && rest[0] == '/' ? rest+1 : rest);
         else
                 return strjoin(path,
                                rest ? (endswith(path, "/") ? "" : "/") : NULL,
-                               rest && rest[0] == '/' ? rest+1 : rest,
-                               NULL);
+                               rest && rest[0] == '/' ? rest+1 : rest);
 }
 
 int find_binary(const char *name, char **ret) {
@@ -494,7 +492,7 @@ int find_binary(const char *name, char **ret) {
                 if (!path_is_absolute(element))
                         continue;
 
-                j = strjoin(element, "/", name, NULL);
+                j = strjoin(element, "/", name);
                 if (!j)
                         return -ENOMEM;
 
diff --git a/src/basic/process-util.c b/src/basic/process-util.c
index 54b644ad56..48a5c719af 100644
--- a/src/basic/process-util.c
+++ b/src/basic/process-util.c
@@ -236,14 +236,14 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
                         return h;
 
                 if (max_length == 0)
-                        r = strjoin("[", t, "]", NULL);
+                        r = strjoin("[", t, "]");
                 else {
                         size_t l;
 
                         l = strlen(t);
 
                         if (l + 3 <= max_length)
-                                r = strjoin("[", t, "]", NULL);
+                                r = strjoin("[", t, "]");
                         else if (max_length <= 6) {
 
                                 r = new(char, max_length);
@@ -263,7 +263,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
                                         e--;
                                 *e = 0;
 
-                                r = strjoin("[", t, "...]", NULL);
+                                r = strjoin("[", t, "...]");
                         }
                 }
                 if (!r)
diff --git a/src/basic/string-util.c b/src/basic/string-util.c
index 6b06e643c9..2ba3604ba0 100644
--- a/src/basic/string-util.c
+++ b/src/basic/string-util.c
@@ -218,7 +218,7 @@ char *strappend(const char *s, const char *suffix) {
         return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
 }
 
-char *strjoin(const char *x, ...) {
+char *strjoin_real(const char *x, ...) {
         va_list ap;
         size_t l;
         char *r, *p;
diff --git a/src/basic/string-util.h b/src/basic/string-util.h
index d029d538bd..0175803302 100644
--- a/src/basic/string-util.h
+++ b/src/basic/string-util.h
@@ -116,7 +116,8 @@ const char* split(const char **state, size_t *l, const char *separator, bool quo
 char *strappend(const char *s, const char *suffix);
 char *strnappend(const char *s, const char *suffix, size_t length);
 
-char *strjoin(const char *x, ...) _sentinel_;
+char *strjoin_real(const char *x, ...) _sentinel_;
+#define strjoin(a, ...) strjoin_real((a), __VA_ARGS__, NULL)
 
 #define strjoina(a, ...)                                                \
         ({                                                              \
diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
index fe883b95c7..0a6efa449a 100644
--- a/src/basic/unit-name.c
+++ b/src/basic/unit-name.c
@@ -273,7 +273,7 @@ int unit_name_build(const char *prefix, const char *instance, const char *suffix
         if (!instance)
                 s = strappend(prefix, suffix);
         else
-                s = strjoin(prefix, "@", instance, suffix, NULL);
+                s = strjoin(prefix, "@", instance, suffix);
         if (!s)
                 return -ENOMEM;
 
@@ -554,7 +554,7 @@ int unit_name_from_path_instance(const char *prefix, const char *path, const cha
         if (r < 0)
                 return r;
 
-        s = strjoin(prefix, "@", p, suffix, NULL);
+        s = strjoin(prefix, "@", p, suffix);
         if (!s)
                 return -ENOMEM;
 
diff --git a/src/basic/util.c b/src/basic/util.c
index ec7939dc83..0f65e4839c 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -131,7 +131,7 @@ static int do_execute(char **directories, usec_t timeout, char *argv[]) {
                         if (r < 0)
                                 return log_oom();
 
-                        path = strjoin(*directory, "/", de->d_name, NULL);
+                        path = strjoin(*directory, "/", de->d_name);
                         if (!path)
                                 return log_oom();