From ea3c6f7bf01d0642b2539e0dbe011aabdff3557a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=A9ry=20Debongnie?= <ged@odoo.com>
Date: Wed, 7 Jul 2021 10:31:37 +0200
Subject: [PATCH] [FIX] slots: make sure handlers are properly bound to
 component

In some situations (a slot inside a slot), the combine method was
wrongly copying all properties of the scope into the context, which
caused the event handling system to wrongly use a subobject as component
(since it detects the fact that __owl__ is a own property_).
Consequently, we could have very subtle issue with some properties being
shadowed by a sub object.
---
 src/qweb/qweb.ts              |  5 ++--
 tests/component/slots.test.ts | 46 +++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/src/qweb/qweb.ts b/src/qweb/qweb.ts
index 2edc3b0c..2de45442 100644
--- a/src/qweb/qweb.ts
+++ b/src/qweb/qweb.ts
@@ -139,8 +139,9 @@ const UTILS: Utils = {
   },
   combine(context, scope) {
     const clone = Object.create(context);
-    for (let k in scope) {
-      clone[k] = scope[k];
+    while (!isComponent(scope)) {
+      Object.assign(clone, scope);
+      scope = scope.__proto__;
     }
     return clone;
   },
diff --git a/tests/component/slots.test.ts b/tests/component/slots.test.ts
index b95bcaae..54297cdc 100644
--- a/tests/component/slots.test.ts
+++ b/tests/component/slots.test.ts
@@ -1257,4 +1257,50 @@ describe("t-slot directive", () => {
       `<div><div class="slotted"><div class="slot"><div class="child"></div></div></div></div>`
     );
   });
+
+  test("t-slot scope context", async () => {
+    expect.assertions(1);
+
+    class Wrapper extends Component {
+      static template = xml`<t t-slot="default"/>`;
+    }
+
+    let dialog;
+
+    class Dialog extends Component {
+      static template = xml`
+        <Wrapper>
+          <div t-on-click="onClick">
+            <t t-slot="default" />
+          </div>
+        </Wrapper>
+      `;
+
+      static components = { Wrapper };
+
+      setup() {
+        dialog = this;
+      }
+
+      onClick(ev) {
+        // we do not use expect(this).toBe(dialog) here because if it fails, it
+        // may blow up jest because it then tries to compute a diff, which is
+        // infinite if there is a cycle
+        expect(this === dialog).toBe(true);
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`
+        <Dialog>
+            <button>The Button</button>
+        </Dialog>`;
+      static components = { Dialog };
+    }
+
+    await mount(Parent, { target: fixture });
+
+    document.querySelector("button").click();
+    await nextTick();
+  });
 });