6 files changed, 120 insertions, 5 deletions
diff --git a/components/script/dom/htmlbuttonelement.rs b/components/script/dom/htmlbuttonelement.rs
index b7c7da1e9bf..49541a2d4a0 100755
--- a/components/script/dom/htmlbuttonelement.rs
+++ b/components/script/dom/htmlbuttonelement.rs
@@ -307,7 +307,7 @@ impl Activatable for HTMLButtonElement {
                 if let Some(owner) = self.form_owner() {
                     owner.submit(
                         SubmittedFrom::NotFromForm,
-                        FormSubmitter::ButtonElement(self.clone()),
+                        FormSubmitter::ButtonElement(self),
                     );
                 }
             },
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index ebbe1d49615..bf59dc0280b 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -48,6 +48,7 @@ use crate::dom::node::{Node, NodeFlags, ShadowIncluding};
 use crate::dom::node::{UnbindContext, VecPreOrderInsertionHelper};
 use crate::dom::nodelist::{NodeList, RadioListMode};
 use crate::dom::radionodelist::RadioNodeList;
+use crate::dom::submitevent::SubmitEvent;
 use crate::dom::validitystate::ValidationFlags;
 use crate::dom::virtualmethods::VirtualMethods;
 use crate::dom::window::Window;
@@ -604,10 +605,29 @@ impl HTMLFormElement {
             }
         }
         // Step 7
+        // spec calls this "submitterButton" but it doesn't have to be a button,
+        // just not be the form itself
+        let submitter_button = match submitter {
+            FormSubmitter::FormElement(f) => {
+                if f == self {
+                    None
+                } else {
+                    Some(f.upcast::<HTMLElement>())
+                }
+            },
+            FormSubmitter::InputElement(i) => Some(i.upcast::<HTMLElement>()),
+            FormSubmitter::ButtonElement(b) => Some(b.upcast::<HTMLElement>()),
+        };
         if submit_method_flag == SubmittedFrom::NotFromForm {
-            let event = self
-                .upcast::<EventTarget>()
-                .fire_bubbling_cancelable_event(atom!("submit"));
+            let event = SubmitEvent::new(
+                &self.global(),
+                atom!("submit"),
+                true,
+                true,
+                submitter_button.map(|s| DomRoot::from_ref(s)),
+            );
+            let event = event.upcast::<Event>();
+            event.fire(self.upcast::<EventTarget>());
             if event.DefaultPrevented() {
                 return;
             }
diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index a8587b58ed0..88b2e688d65 100755
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -2470,7 +2470,7 @@ impl Activatable for HTMLInputElement {
                 self.form_owner().map(|o| {
                     o.submit(
                         SubmittedFrom::NotFromForm,
-                        FormSubmitter::InputElement(self.clone()),
+                        FormSubmitter::InputElement(self),
                     )
                 });
             },
diff --git a/components/script/dom/mod.rs b/components/script/dom/mod.rs
index 282d3b66d60..c1a1ab72354 100644
--- a/components/script/dom/mod.rs
+++ b/components/script/dom/mod.rs
@@ -484,6 +484,7 @@ pub mod storageevent;
 pub mod stylepropertymapreadonly;
 pub mod stylesheet;
 pub mod stylesheetlist;
+pub mod submitevent;
 pub mod svgelement;
 pub mod svggraphicselement;
 pub mod svgsvgelement;
diff --git a/components/script/dom/submitevent.rs b/components/script/dom/submitevent.rs
new file mode 100644
index 00000000000..17f8e7fd003
--- /dev/null
+++ b/components/script/dom/submitevent.rs
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use crate::dom::bindings::codegen::Bindings::EventBinding::EventMethods;
+use crate::dom::bindings::codegen::Bindings::SubmitEventBinding;
+use crate::dom::bindings::codegen::Bindings::SubmitEventBinding::SubmitEventMethods;
+use crate::dom::bindings::inheritance::Castable;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::event::Event;
+use crate::dom::globalscope::GlobalScope;
+use crate::dom::htmlelement::HTMLElement;
+use crate::dom::window::Window;
+use dom_struct::dom_struct;
+use servo_atoms::Atom;
+
+#[dom_struct]
+#[allow(non_snake_case)]
+pub struct SubmitEvent {
+    event: Event,
+    submitter: Option<DomRoot<HTMLElement>>,
+}
+
+impl SubmitEvent {
+    fn new_inherited(submitter: Option<DomRoot<HTMLElement>>) -> SubmitEvent {
+        SubmitEvent {
+            event: Event::new_inherited(),
+            submitter: submitter,
+        }
+    }
+
+    pub fn new(
+        global: &GlobalScope,
+        type_: Atom,
+        bubbles: bool,
+        cancelable: bool,
+        submitter: Option<DomRoot<HTMLElement>>,
+    ) -> DomRoot<SubmitEvent> {
+        let ev = reflect_dom_object(
+            Box::new(SubmitEvent::new_inherited(submitter)),
+            global,
+            SubmitEventBinding::Wrap,
+        );
+        {
+            let event = ev.upcast::<Event>();
+            event.init_event(type_, bubbles, cancelable);
+        }
+        ev
+    }
+
+    #[allow(non_snake_case)]
+    pub fn Constructor(
+        window: &Window,
+        type_: DOMString,
+        init: &SubmitEventBinding::SubmitEventInit,
+    ) -> DomRoot<SubmitEvent> {
+        SubmitEvent::new(
+            &window.global(),
+            Atom::from(type_),
+            init.parent.bubbles,
+            init.parent.cancelable,
+            init.submitter.as_ref().map(|s| DomRoot::from_ref(&**s)),
+        )
+    }
+}
+
+impl SubmitEventMethods for SubmitEvent {
+    /// <https://dom.spec.whatwg.org/#dom-event-istrusted>
+    fn IsTrusted(&self) -> bool {
+        self.event.IsTrusted()
+    }
+
+    /// https://html.spec.whatwg.org/multipage/#dom-submitevent-submitter
+    fn GetSubmitter(&self) -> Option<DomRoot<HTMLElement>> {
+        self.submitter.as_ref().map(|s| DomRoot::from_ref(&**s))
+    }
+}
diff --git a/components/script/dom/webidls/SubmitEvent.webidl b/components/script/dom/webidls/SubmitEvent.webidl
new file mode 100644
index 00000000000..f5b2c49257d
--- /dev/null
+++ b/components/script/dom/webidls/SubmitEvent.webidl
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+// https://html.spec.whatwg.org/multipage/#submitevent
+[Exposed=Window]
+interface SubmitEvent : Event {
+    constructor(DOMString typeArg, optional SubmitEventInit eventInitDict = {});
+
+    readonly attribute HTMLElement? submitter;
+};
+
+dictionary SubmitEventInit : EventInit {
+    HTMLElement? submitter = null;
+};