document parent_path()

src/path.c

@@ -225,13 +225,23 @@ void pathcpy_trunc(char *dest, const char *src)
 char *parent_path(char *path_max_tmp, const char *path)
 {
 	char *c;
+	static const int handle_trailing_slashes = 0;
 
 	pathcpy_trunc(path_max_tmp, path);
+
+	if (handle_trailing_slashes) {
+		size_t last_char = strlen(path_max_tmp) - 1;
+
+		while (last_char > 0 && path_max_tmp[last_char] == '/')
+			path_max_tmp[last_char--] = '\0';
+	}
+
 	c = strrchr(path_max_tmp,'/');
 
 	if (c == NULL)
 		path_max_tmp[0] = '\0';
 	else {
+		/* strip redundant slashes: */
 		while ((path_max_tmp <= c) && *(--c) == '/')	/* nothing */
 			;
 		c[1] = '\0';

src/path.h

@@ -60,13 +60,20 @@ char *pfx_dir(char *dst,
               const char *path, const size_t path_len,
               const char *pfx, const size_t pfx_len);
 
-/* relative music path to absolute music path
- * char * passed is a static variable, so don't free it
- */
+/* relative music path to absolute music path */
 char *rmp2amp_r(char *dst, const char *rel_path);
 
+/* relative playlist path to absolute playlist path */
 char *rpp2app_r(char *dst, const char *rel_path);
 
+/*
+ * parent_path - saner version of dirname(3) with slightly different semantics
+ *  - we will return "" instead of "." or "/" if we have no parent
+ *    this is because we only deal with internal paths
+ *  - we always skip over redundant slashes in the middle, if there are any
+ *  - we will never get meaningful paths with trailing slashes in our callers
+ *    (set handle_trailing_slashes to true if we do)
+ */
 char *parent_path(char *path_max_tmp, const char *path);
 
 /* strips extra "///" and leading "/" and trailing "/" */