servo · bors-servo · Sep 28, 2016 · Sep 21, 2016 · mbrubeck · Sep 21, 2016
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
@@ -98,7 +98,7 @@ impl HTMLFormElementMethods for HTMLFormElement {
     make_setter!(SetAcceptCharset, "accept-charset");
 
     // https://html.spec.whatwg.org/multipage/#dom-fs-action
-    make_url_or_base_getter!(Action, "action");
+    make_string_or_document_url_getter!(Action, "action");
 
     // https://html.spec.whatwg.org/multipage/#dom-fs-action
     make_setter!(SetAction, "action");
@@ -295,7 +295,7 @@ impl HTMLFormElement {
     pub fn submit(&self, submit_method_flag: SubmittedFrom, submitter: FormSubmitter) {
         // Step 1
         let doc = document_from_node(self);
-        let base = doc.url();
+        let base = doc.base_url();
         // TODO: Handle browsing contexts (Step 2, 3)
         // Step 4
         if submit_method_flag == SubmittedFrom::NotFromForm &&

diff --git a/components/script/dom/macros.rs b/components/script/dom/macros.rs
@@ -123,6 +123,26 @@ macro_rules! make_url_or_base_getter(
     );
 );
 
+#[macro_export]
+macro_rules! make_string_or_document_url_getter(
+    ( $attr:ident, $htmlname:tt ) => (
+        fn $attr(&self) -> DOMString {
+            use dom::bindings::inheritance::Castable;
+            use dom::element::Element;
+            use dom::node::document_from_node;
+            let element = self.upcast::<Element>();
+            let val = element.get_string_attribute(&atom!($htmlname));
+
+            if val.is_empty() {
+                let doc = document_from_node(self);
+                DOMString::from(doc.url().clone().into_string())
+            } else {
+                val
+            }
+        }
+    );
+);
+
 #[macro_export]
 macro_rules! make_enumerated_getter(
     ( $attr:ident, $htmlname:tt, $default:expr, $(($choices: pat))|+) => (

diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json

     "deleted_reftests": {},
     "items": {
       "testharness": {
+        "html/semantics/forms/the-form-element/form-action-url.html": [
+          {
+            "path": "html/semantics/forms/the-form-element/form-action-url.html",
+            "url": "/html/semantics/forms/the-form-element/form-action-url.html"
+          }
+        ],
         "html/semantics/forms/the-select-element/common-HTMLOptionsCollection-add.html": [
           {
             "path": "html/semantics/forms/the-select-element/common-HTMLOptionsCollection-add.html",
diff --git a/tests/wpt/web-platform-tests/html/semantics/forms/the-form-element/form-action-url.html b/tests/wpt/web-platform-tests/html/semantics/forms/the-form-element/form-action-url.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+  var t = async_test("Submit a form from an iframe with a base url");
+  var success = function() { t.done(); };
+</script>
+
+<iframe src="resources/form-action-url-iframe.html">
diff --git a/...latform-tests/html/semantics/forms/the-form-element/resources/form-action-url-iframe.html b/...latform-tests/html/semantics/forms/the-form-element/resources/form-action-url-iframe.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<base href="target/"></base>
+
+<form action="form-action-url-target.html">
+  <input type="submit" value="Submit" /> 
+</form>
+
+<script>
+  var form = document.getElementsByTagName("form")[0];
+  form.submit();
+</script>
diff --git a/...-tests/html/semantics/forms/the-form-element/resources/target/form-action-url-target.html b/...-tests/html/semantics/forms/the-form-element/resources/target/form-action-url-target.html
@@ -0,0 +1,4 @@
+<!doctype html>
+<script>
+  window.parent.success();
+</script>