tree-wide: get rid of strappend()

It's a special case of strjoin(), so no need to keep both. In particular
as typing strjoin() is even shoert than strappend().

src/basic/btrfs-util.c

@@ -1517,12 +1517,7 @@ static int subvol_snapshot_children(
                         if (ioctl(old_fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0)
                                 return -errno;
 
-                        /* The kernel returns an empty name if the
-                         * subvolume is in the top-level directory,
-                         * and otherwise appends a slash, so that we
-                         * can just concatenate easily here, without
-                         * adding a slash. */
-                        c = strappend(ino_args.name, p);
+                        c = path_join(ino_args.name, p);
                         if (!c)
                                 return -ENOMEM;
 

src/basic/cgroup-util.c

@@ -1922,7 +1922,7 @@ char *cg_escape(const char *p) {
         }
 
         if (need_prefix)
-                return strappend("_", p);
+                return strjoin("_", p);
 
         return strdup(p);
 }

src/basic/env-util.c

@@ -567,7 +567,7 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
 
                                 t = strv_env_get_n(env, word+2, e-word-2, flags);
 
-                                k = strappend(r, t);
+                                k = strjoin(r, t);
                                 if (!k)
                                         return NULL;
 
@@ -623,7 +623,7 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
                                 else if (!t && state == DEFAULT_VALUE)
                                         t = v = replace_env_n(test_value, e-test_value, env, flags);
 
-                                k = strappend(r, t);
+                                k = strjoin(r, t);
                                 if (!k)
                                         return NULL;
 
@@ -642,7 +642,7 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
 
                                 t = strv_env_get_n(env, word+1, e-word-1, flags);
 
-                                k = strappend(r, t);
+                                k = strjoin(r, t);
                                 if (!k)
                                         return NULL;
 
@@ -661,7 +661,7 @@ char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
                 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
 
                 t = strv_env_get_n(env, word+1, e-word-1, flags);
-                return strappend(r, t);
+                return strjoin(r, t);
         } else
                 return strnappend(r, word, e-word);
 }

src/basic/io-util.c

@@ -257,7 +257,7 @@ ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) {
 char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) {
         char *x;
 
-        x = strappend(field, value);
+        x = strjoin(field, value);
         if (x)
                 iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x);
         return x;
@@ -312,7 +312,7 @@ int iovw_put_string_field(struct iovec_wrapper *iovw, const char *field, const c
         _cleanup_free_ char *x = NULL;
         int r;
 
-        x = strappend(field, value);
+        x = strjoin(field, value);
         if (!x)
                 return log_oom();
 

src/basic/memfd-util.c

@@ -41,7 +41,7 @@ int memfd_new(const char *name) {
                         if (!e)
                                 return -ENOMEM;
 
-                        g = strappend("sd-", e);
+                        g = strjoin("sd-", e);
                         if (!g)
                                 return -ENOMEM;
 

src/basic/string-util.c

@@ -206,10 +206,6 @@ char *strnappend(const char *s, const char *suffix, size_t b) {
         return r;
 }
 
-char *strappend(const char *s, const char *suffix) {
-        return strnappend(s, suffix, strlen_ptr(suffix));
-}
-
 char *strjoin_real(const char *x, ...) {
         va_list ap;
         size_t l;

src/basic/string-util.h

@@ -108,7 +108,6 @@ const char* split(const char **state, size_t *l, const char *separator, SplitFla
 #define _FOREACH_WORD(word, length, s, separator, flags, state)         \
         for ((state) = (s), (word) = split(&(state), &(length), (separator), (flags)); (word); (word) = split(&(state), &(length), (separator), (flags)))
 
-char *strappend(const char *s, const char *suffix);
 char *strnappend(const char *s, const char *suffix, size_t length);
 
 char *strjoin_real(const char *x, ...) _sentinel_;

src/basic/strv.c

@@ -233,7 +233,7 @@ int strv_extend_strv_concat(char ***a, char **b, const char *suffix) {
         STRV_FOREACH(s, b) {
                 char *v;
 
-                v = strappend(*s, suffix);
+                v = strjoin(*s, suffix);
                 if (!v)
                         return -ENOMEM;
 

src/basic/unit-def.c

@@ -15,7 +15,7 @@ char *unit_dbus_path_from_name(const char *name) {
         if (!e)
                 return NULL;
 
-        return strappend("/org/freedesktop/systemd1/unit/", e);
+        return strjoin("/org/freedesktop/systemd1/unit/", e);
 }
 
 int unit_name_from_dbus_path(const char *path, char **name) {

src/basic/unit-name.c

@@ -402,7 +402,7 @@ int unit_name_path_escape(const char *f, char **ret) {
 }
 
 int unit_name_path_unescape(const char *f, char **ret) {
-        char *s;
+        _cleanup_free_ char *s = NULL;
         int r;
 
         assert(f);
@@ -415,34 +415,27 @@ int unit_name_path_unescape(const char *f, char **ret) {
                 if (!s)
                         return -ENOMEM;
         } else {
-                char *w;
+                _cleanup_free_ char *w = NULL;
 
                 r = unit_name_unescape(f, &w);
                 if (r < 0)
                         return r;
 
                 /* Don't accept trailing or leading slashes */
-                if (startswith(w, "/") || endswith(w, "/")) {
-                        free(w);
+                if (startswith(w, "/") || endswith(w, "/"))
                         return -EINVAL;
-                }
 
                 /* Prefix a slash again */
-                s = strappend("/", w);
-                free(w);
+                s = strjoin("/", w);
                 if (!s)
                         return -ENOMEM;
 
-                if (!path_is_normalized(s)) {
-                        free(s);
+                if (!path_is_normalized(s))
                         return -EINVAL;
-                }
         }
 
         if (ret)
-                *ret = s;
-        else
-                free(s);
+                *ret = TAKE_PTR(s);
 
         return 0;
 }
@@ -519,7 +512,7 @@ int unit_name_from_path(const char *path, const char *suffix, char **ret) {
         if (r < 0)
                 return r;
 
-        s = strappend(p, suffix);
+        s = strjoin(p, suffix);
         if (!s)
                 return -ENOMEM;
 
@@ -719,7 +712,7 @@ int slice_build_subslice(const char *slice, const char *name, char **ret) {
                 return -EINVAL;
 
         if (streq(slice, SPECIAL_ROOT_SLICE))
-                subslice = strappend(name, ".slice");
+                subslice = strjoin(name, ".slice");
         else {
                 char *e;