Fix panic in set_path for file URLs

url/Cargo.toml

@@ -2,7 +2,7 @@
 
 name = "url"
 # When updating version, also modify html_root_url in the lib.rs
-version = "2.4.0"
+version = "2.4.1"
 authors = ["The rust-url developers"]
 
 description = "URL library for Rust, based on the WHATWG URL Standard"

url/src/lib.rs

@@ -134,7 +134,7 @@ url = { version = "2", features = ["debugger_visualizer"] }
 
 */
 
-#![doc(html_root_url = "https://docs.rs/url/2.4.0")]
+#![doc(html_root_url = "https://docs.rs/url/2.4.1")]
 #![cfg_attr(
     feature = "debugger_visualizer",
     debugger_visualizer(natvis_file = "../../debug_metadata/url.natvis")

url/src/parser.rs

@@ -1202,6 +1202,7 @@ impl<'a> Parser<'a> {
                     _ => {
                         self.check_url_code_point(c, &input);
                         if scheme_type.is_file()
+                            && self.serialization.len() > path_start
                             && is_normalized_windows_drive_letter(
                                 &self.serialization[path_start + 1..],
                             )

url/tests/unit.rs

@@ -472,7 +472,7 @@ fn append_trailing_slash() {
 fn extend_query_pairs_then_mutate() {
     let mut url: Url = "http://localhost:6767/foo/bar".parse().unwrap();
     url.query_pairs_mut()
-        .extend_pairs(vec![("auth", "my-token")].into_iter());
+        .extend_pairs(vec![("auth", "my-token")]);
     url.check_invariants().unwrap();
     assert_eq!(
         url.to_string(),
@@ -1298,3 +1298,11 @@ fn test_file_with_drive_and_path() {
     let url2 = url::Url::join(&url, s2).unwrap();
     assert_eq!(url2.to_string(), "file:///p:/a");
 }
+
+#[test]
+fn issue_864() {
+    let mut url = url::Url::parse("file://").unwrap();
+    dbg!(&url);
+    url.set_path("x");
+    dbg!(&url);
+}