From 1fc5a24e9887d5cd83303c24f32c9fb3d01f2338 Mon Sep 17 00:00:00 2001
From: Andrey Mnatsakanov <andrey@3ig.dev>
Date: Sun, 26 Jul 2026 12:32:27 +0200
Subject: [PATCH] fix(js): keep the current URL when pushState/replaceState
 omit url

resolveOrFallback(undefined) returned undefined, so applyVirtual set
__virtualUrl to null and location reverted to the document URL. Per the HTML
spec a missing url keeps the current document URL; return __currentUrl() so the
new history entry captures the current location instead of clearing it.

Fixes #496
---
 crates/obscura-js/js/bootstrap.js |  5 ++++-
 crates/obscura-js/src/runtime.rs  | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/crates/obscura-js/js/bootstrap.js b/crates/obscura-js/js/bootstrap.js
index 3ef371a..e3073d8 100644
--- a/crates/obscura-js/js/bootstrap.js
+++ b/crates/obscura-js/js/bootstrap.js
@@ -5613,7 +5613,10 @@ globalThis.atob = globalThis.atob || ((s) => { const c="ABCDEFGHIJKLMNOPQRSTUVWX
   const stack = [{state: null, url: undefined}]; // initial entry; url=undefined means "use document URL"
   let idx = 0;
   const resolveOrFallback = (url) => {
-    if (url === null || url === undefined) return undefined;
+    // A missing url (pushState/replaceState called with < 3 args) keeps the
+    // current document URL per the HTML spec — capture it so the entry does not
+    // reset location back to the original document URL.
+    if (url === null || url === undefined) return __currentUrl();
     try { return new URL(String(url), __currentUrl()).href; } catch (e) { return String(url); }
   };
   const applyVirtual = () => {
diff --git a/crates/obscura-js/src/runtime.rs b/crates/obscura-js/src/runtime.rs
index fdfeb4d..5b4d27e 100644
--- a/crates/obscura-js/src/runtime.rs
+++ b/crates/obscura-js/src/runtime.rs
@@ -1317,6 +1317,28 @@ mod tests {
         rt
     }
 
+    #[test]
+    fn replace_state_without_url_preserves_current_location() {
+        let mut rt = setup_runtime("<html><body></body></html>");
+        let path = rt
+            .evaluate(
+                "(function(){history.pushState({}, '', '/dashboard'); history.replaceState({scroll:1}); return location.pathname;})()",
+            )
+            .unwrap();
+        assert_eq!(path, serde_json::json!("/dashboard"));
+    }
+
+    #[test]
+    fn push_state_without_url_preserves_current_location() {
+        let mut rt = setup_runtime("<html><body></body></html>");
+        let path = rt
+            .evaluate(
+                "(function(){history.pushState({}, '', '/a'); history.pushState({b:1}); return location.pathname;})()",
+            )
+            .unwrap();
+        assert_eq!(path, serde_json::json!("/a"));
+    }
+
     #[test]
     fn test_document_title() {
         let mut rt = setup_runtime("<html><head><title>Test</title></head><body></body></html>");