mapper, update, ...: use g_build_filename(), G_DIR_SEPARATOR, ...

Try to be as portable as possible, use GLib path name functions and
macros.

src/decoder_thread.c

@@ -74,7 +74,7 @@ decoder_file_decode(const struct decoder_plugin *plugin,
 	assert(decoder->stream_tag == NULL);
 	assert(decoder->decoder_tag == NULL);
 	assert(path != NULL);
-	assert(path[0] == '/');
+	assert(g_path_is_absolute(path));
 	assert(dc.state == DECODE_STATE_START);
 
 	decoder_unlock();

src/input/file_input_plugin.c

@@ -39,7 +39,7 @@ input_file_open(struct input_stream *is, const char *filename)
 
 	char* pathname = g_strdup(filename);
 
-	if (filename[0] != '/')
+	if (!g_path_is_absolute(filename))
 	{
 		g_free(pathname);
 		return false;

src/mapper.c

@@ -169,10 +169,10 @@ map_fs_to_utf8(const char *path_fs)
 {
 	if (music_dir != NULL &&
 	    strncmp(path_fs, music_dir, music_dir_length) == 0 &&
-	    path_fs[music_dir_length] == '/')
+	    G_IS_DIR_SEPARATOR(path_fs[music_dir_length]))
 		/* remove musicDir prefix */
 		path_fs += music_dir_length + 1;
-	else if (path_fs[0] == '/')
+	else if (G_IS_DIR_SEPARATOR(path_fs[0]))
 		/* not within musicDir */
 		return NULL;
 

src/playlist_save.c

@@ -54,7 +54,7 @@ playlist_print_uri(FILE *file, const char *uri)
 	char *s;
 
 	if (playlist_saveAbsolutePaths && !uri_has_scheme(uri) &&
-	    uri[0] != '/')
+	    !g_path_is_absolute(uri))
 		s = map_uri_fs(uri);
 	else
 		s = utf8_to_fs_charset(uri);

src/song_update.c

@@ -39,7 +39,7 @@ song_file_load(const char *path, struct directory *parent)
 	struct song *song;
 	bool ret;
 
-	assert((parent == NULL) == (*path == '/'));
+	assert((parent == NULL) == g_path_is_absolute(path));
 	assert(!uri_has_scheme(path));
 	assert(strchr(path, '\n') == NULL);
 

src/update_walk.c

@@ -620,7 +620,7 @@ skip_symlink(const struct directory *directory, const char *utf8_name)
 
 	p = buffer;
 	while (*p == '.') {
-		if (p[1] == '.' && p[2] == '/') {
+		if (p[1] == '.' && G_IS_DIR_SEPARATOR(p[2])) {
 			/* "../" moves to parent directory */
 			directory = directory->parent;
 			if (directory == NULL) {
@@ -630,7 +630,7 @@ skip_symlink(const struct directory *directory, const char *utf8_name)
 				return !follow_outside_symlinks;
 			}
 			p += 3;
-		} else if (p[1] == '/')
+		} else if (G_IS_DIR_SEPARATOR(p[1]))
 			/* eliminate "./" */
 			p += 2;
 		else
@@ -675,8 +675,7 @@ updateDirectory(struct directory *directory, const struct stat *st)
 		return false;
 	}
 
-	exclude_path_fs  = g_strconcat(path_fs, G_DIR_SEPARATOR_S,
-				       ".mpdignore", NULL);
+	exclude_path_fs  = g_build_filename(path_fs, ".mpdignore", NULL);
 	exclude_list = exclude_list_load(exclude_path_fs);
 	g_free(exclude_path_fs);
 

src/utils.c

@@ -44,7 +44,7 @@
 char *parsePath(char *path)
 {
 #ifndef WIN32
-	if (path[0] != '/' && path[0] != '~') {
+	if (!g_path_is_absolute(path) && path[0] != '~') {
 		g_warning("\"%s\" is not an absolute path", path);
 		return NULL;
 	} else if (path[0] == '~') {