stdlib: Add regression test for fs::connect and a FIXME

src/lib/fs.rs

@@ -19,6 +19,7 @@ fn dirname(path p) -> path {
     ret str::substr(p, 0u, i as uint);
 }
 
+// FIXME: Need some typestate to avoid bounds check when len(pre) == 0
 fn connect(path pre, path post) -> path {
     auto len = str::byte_len(pre);
     if (pre.(len - 1u) == (os_fs::path_sep as u8)) { // Trailing '/'?

src/test/run-pass/lib-fs.rs

@@ -0,0 +1,15 @@
+use std;
+
+import std::fs;
+
+fn test_connect() {
+  auto slash = fs::path_sep();
+  assert (fs::connect("a", "b")
+          == "a" + slash + "b");
+  assert (fs::connect("a" + slash, "b")
+          == "a" + slash + "b");
+}
+
+fn main() {
+  test_connect();
+}