[FIX] compiler: compile named slot in t-component in named slot

Previously, if a t-set-slot was inside a t-component itself inside a
t-set-slot the parser would crash, because the slot is removed from the
template before compiling its content, causing a further check's
assumption to be broken (the t-set-slot remains connected to the
component's xml node)

src/compiler/parser.ts

@@ -740,14 +740,14 @@ function parseComponent(node: Element, ctx: ParsingContext): AST | null {
       // be ignored)
       let el = slotNode.parentElement!;
       let isInSubComponent = false;
-      while (el !== clone) {
+      while (el && el !== clone) {
         if (el!.hasAttribute("t-component") || el!.tagName[0] === el!.tagName[0].toUpperCase()) {
           isInSubComponent = true;
           break;
         }
         el = el.parentElement!;
       }
-      if (isInSubComponent) {
+      if (isInSubComponent || !el) {
         continue;
       }
 

tests/components/__snapshots__/slots.test.ts.snap

@@ -1066,6 +1066,45 @@ exports[`slots multiple slots containing components 3`] = `
 }"
 `;
 
+exports[`slots named slot inside named slot in t-component 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { capture, markRaw } = helpers;
+  const comp1 = app.createComponent(null, false, true, false, []);
+  const comp2 = app.createComponent(\`Child\`, true, true, false, []);
+
+  function slot1(ctx, node, key = \\"\\") {
+    const b2 = text(\` outer \`);
+    const ctx2 = capture(ctx);
+    const Comp1 = ctx['Child'];
+    const b4 = toggler(Comp1, comp1({slots: markRaw({'brol': {__render: slot2.bind(this), __ctx: ctx2}})}, (Comp1).name + key + \`__1\`, node, this, Comp1));
+    return multi([b2, b4]);
+  }
+
+  function slot2(ctx, node, key = \\"\\") {
+    return text(ctx['value']);
+  }
+
+  return function template(ctx, node, key = \\"\\") {
+    const ctx1 = capture(ctx);
+    return comp2({slots: markRaw({'brol': {__render: slot1.bind(this), __ctx: ctx1}})}, key + \`__2\`, node, this, null);
+  }
+}"
+`;
+
+exports[`slots named slot inside named slot in t-component 2`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { callSlot } = helpers;
+
+  return function template(ctx, node, key = \\"\\") {
+    return callSlot(ctx, node, key, 'brol', false, {});
+  }
+}"
+`;
+
 exports[`slots named slot inside slot 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/slots.test.ts

@@ -1673,6 +1673,31 @@ describe("slots", () => {
     expect(fixture.innerHTML).toBe("<div><div><p>Ablip</p><div><p>Bblip</p></div></div></div>");
   });
 
+  test("named slot inside named slot in t-component", async () => {
+    class Child extends Component {
+      static template = xml`<t t-slot="brol"/>`;
+    }
+    class Parent extends Component {
+      static template = xml`
+        <Child>
+          <t t-set-slot="brol">
+            outer
+            <t t-component="Child">
+              <t t-set-slot="brol">
+                <t t-esc="value"/>
+              </t>
+            </t>
+          </t>
+        </Child>`;
+      static components = { Child };
+      Child = Child;
+      value = "inner";
+    }
+    await mount(Parent, fixture);
+
+    expect(fixture.innerHTML).toBe(" outer inner");
+  });
+
   test("can render only empty slot", async () => {
     class Parent extends Component {
       static template = xml`<t t-slot="default"/>`;