path-util: Add path_simplify_full()

Sometimes its useful to keep a trailing slash in the path so let's
add path_simplify_full() and a flag to do just that.

src/basic/path-util.c

@@ -344,8 +344,8 @@ char **path_strv_resolve_uniq(char **l, const char *root) {
         return strv_uniq(l);
 }
 
-char *path_simplify(char *path) {
-        bool add_slash = false;
+char *path_simplify_full(char *path, PathSimplifyFlags flags) {
+        bool add_slash = false, keep_trailing_slash;
         char *f = ASSERT_PTR(path);
         int r;
 
@@ -359,6 +359,8 @@ char *path_simplify(char *path) {
         if (isempty(path))
                 return path;
 
+        keep_trailing_slash = FLAGS_SET(flags, PATH_SIMPLIFY_KEEP_TRAILING_SLASH) && endswith(path, "/");
+
         if (path_is_absolute(path))
                 f++;
 
@@ -388,6 +390,9 @@ char *path_simplify(char *path) {
         if (f == path)
                 *f++ = '.';
 
+        if (*(f-1) != '/' && keep_trailing_slash)
+                *f++ = '/';
+
         *f = '\0';
         return path;
 }

src/basic/path-util.h

@@ -76,7 +76,14 @@ char* path_extend_internal(char **x, ...);
 #define path_extend(x, ...) path_extend_internal(x, __VA_ARGS__, POINTER_MAX)
 #define path_join(...) path_extend_internal(NULL, __VA_ARGS__, POINTER_MAX)
 
-char* path_simplify(char *path);
+typedef enum PathSimplifyFlags {
+        PATH_SIMPLIFY_KEEP_TRAILING_SLASH = 1 << 0,
+} PathSimplifyFlags;
+
+char *path_simplify_full(char *path, PathSimplifyFlags flags);
+static inline char* path_simplify(char *path) {
+        return path_simplify_full(path, 0);
+}
 
 static inline bool path_equal_ptr(const char *a, const char *b) {
         return !!a == !!b && (!a || path_equal(a, b));