decoder_plugin: added method container_scan()

[mk: fixed whitespace errors; use delete_song() instead of
songvec_delete()]

src/input/file_input_plugin.c

@@ -35,12 +35,23 @@ input_file_open(struct input_stream *is, const char *filename)
 	int fd, ret;
 	struct stat st;
 
-	if (filename[0] != '/')
-		return false;
+	char* pathname = g_strdup(filename);
 
-	fd = open(filename, O_RDONLY);
+	if (filename[0] != '/')
+	{
+		g_free(pathname);
+		return false;
+	}
+
+	if (stat(filename, &st) < 0) {
+		char* slash = strrchr(pathname, '/');
+		*slash = '\0';
+	}
+
+	fd = open(pathname, O_RDONLY);
 	if (fd < 0) {
 		is->error = errno;
+		g_free(pathname);
 		return false;
 	}
 
@@ -50,13 +61,15 @@ input_file_open(struct input_stream *is, const char *filename)
 	if (ret < 0) {
 		is->error = errno;
 		close(fd);
+		g_free(pathname);
 		return false;
 	}
 
 	if (!S_ISREG(st.st_mode)) {
-		g_debug("Not a regular file: %s\n", filename);
+		g_debug("Not a regular file: %s", pathname);
 		is->error = EINVAL;
 		close(fd);
+		g_free(pathname);
 		return false;
 	}
 
@@ -70,6 +83,8 @@ input_file_open(struct input_stream *is, const char *filename)
 	is->data = GINT_TO_POINTER(fd);
 	is->ready = true;
 
+	g_free(pathname);
+
 	return true;
 }