[FIX] mail: closing hidden chat window should not crash

Before this commit, closing a hidden chat window may crash.

This happens because closing a chat window was always treated as the
closing of a visible chat window, which should make the 1st hidden
chat window visible, if any. This code should not be called when
closing a hidden chat window, otherwise unexpected behaviour are
to be expected, e.g. closing 2nd hidden chat window swaps last visible
with 1st hidden chat window, or even a crash.

This commit makes sure auto-swapping of 1st hidden chat window only
occurs when closing a visible chat window.

opw-3460466

closes odoo/odoo#132458

X-original-commit: b49364b687757385a2a7356d17dc428edafd2767
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/core/common/chat_window_container.xml

@@ -13,7 +13,7 @@
 </t>
 
 <t t-name="mail.ChatWindowHiddenMenu">
-    <Dropdown position="'top-end'" menuClass="'p-0'" togglerClass="'o-mail-ChatWindowHiddenToggler btn d-flex align-items-center rounded-top-3 bg-900'">
+    <Dropdown position="'top-end'" menuClass="'o-mail-ChatWindowHiddenMenu p-0'" togglerClass="'o-mail-ChatWindowHiddenToggler btn d-flex align-items-center rounded-top-3 bg-900'">
         <t t-set-slot="toggler">
             <div class="me-1 fa fa-comments-o"/>
             <div class="mx-1 text-truncate" t-esc="chatWindowService.hidden.length"/>

addons/mail/static/src/core/common/chat_window_service.js

@@ -153,7 +153,7 @@ export class ChatWindowService {
     }
 
     close(chatWindow, { escape = false } = {}) {
-        if (this.maxVisible < this.store.chatWindows.length) {
+        if (!chatWindow.hidden && this.maxVisible < this.store.chatWindows.length) {
             const swaped = this.hidden[0];
             swaped.hidden = false;
             swaped.folded = false;

addons/mail/static/tests/chat_window/chat_window_tests.js

@@ -430,6 +430,45 @@ QUnit.test("open 3 different chat windows: not enough screen width", async (asse
     );
 });
 
+QUnit.test("closing hidden chat window", async (assert) => {
+    const pyEnv = await startServer();
+    pyEnv["discuss.channel"].create([
+        { name: "Ch_1" },
+        { name: "Ch_2" },
+        { name: "Ch_3" },
+        { name: "Ch_4" },
+    ]);
+    patchUiSize({ width: 900 });
+    assert.ok(
+        CHAT_WINDOW_END_GAP_WIDTH * 2 + CHAT_WINDOW_WIDTH * 2 + CHAT_WINDOW_INBETWEEN_WIDTH < 900,
+        "should have enough space to open 2 chat windows simultaneously"
+    );
+    assert.ok(
+        CHAT_WINDOW_END_GAP_WIDTH * 2 + CHAT_WINDOW_WIDTH * 3 + CHAT_WINDOW_INBETWEEN_WIDTH * 2 >
+            900,
+        "should not have enough space to open 3 chat windows simultaneously"
+    );
+    await start();
+    await click("i[aria-label='Messages']");
+    await click(".o-mail-NotificationItem:contains(Ch_1)");
+    await click("i[aria-label='Messages']");
+    await click(".o-mail-NotificationItem:contains(Ch_2)");
+    await click("i[aria-label='Messages']");
+    await click(".o-mail-NotificationItem:contains(Ch_3)");
+    await click("i[aria-label='Messages']");
+    await click(".o-mail-NotificationItem:contains(Ch_4)");
+    await click(".o-mail-ChatWindowHiddenToggler");
+    assert.containsOnce($, ":not(.o-mail-ChatWindowHiddenMenu) .o-mail-ChatWindow:contains(Ch_1)");
+    assert.containsOnce($, ".o-mail-ChatWindowHiddenMenu .o-mail-ChatWindow:contains(Ch_2)");
+    assert.containsOnce($, ".o-mail-ChatWindowHiddenMenu .o-mail-ChatWindow:contains(Ch_3)");
+    assert.containsOnce($, ":not(.o-mail-ChatWindowHiddenMenu) .o-mail-ChatWindow:contains(Ch_4)");
+    await click(".o-mail-ChatWindow:contains(Ch_2) [title='Close Chat Window']");
+    assert.containsOnce($, ":not(.o-mail-ChatWindowHiddenMenu) .o-mail-ChatWindow:contains(Ch_1)");
+    assert.containsNone($, ".o-mail-ChatWindow:contains(Ch_2)");
+    assert.containsOnce($, ".o-mail-ChatWindowHiddenMenu .o-mail-ChatWindow:contains(Ch_3)");
+    assert.containsOnce($, ":not(.o-mail-ChatWindowHiddenMenu) .o-mail-ChatWindow:contains(Ch_4)");
+});
+
 QUnit.test(
     "focus next visible chat window when closing current chat window with ESCAPE [REQUIRE FOCUS]",
     async (assert) => {