1733301 - Incorrect content document focus after active toplevel OS window change

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Karl Tomlinson (:karlt)]

Attachment: log

STR

1. Set pref "focusmanager.testmode" to true.
2. Open a content document b in a new toplevel OS window B from a focused content document a in OS window A.
   (OS window B becomes active.)
3. Activate OS window A again through script (e.g. testharness) before content document b receives focus.

https://treeherder.mozilla.org/jobs?repo=try&revision=44e51d543efc5fbdd6c76c6545cb9ce9845033d0&selectedJob=353045894

Expected: Content document a gets focus.
Actual: Content document b keeps focus.

Sequence of events:

1. Toplevel chrome window A [7fbe4cdc5760] is initially active and element focus is moved to its browser element.
2. The contained content window proxy a [7f173c9a1920] receives focus [actionid 20].
3. Toplevel chrome window B [7fbe277fb060] is shown and becomes active [actionid 23].
4. (Actionid 24 is a no-op B -> B toplevel chrome window change.)
5. focus() is called on toplevel chrome window A [actionid 25] which queues a task to call WindowRaised().
6. gBrowserInit.onDOMContentLoaded() calls focus() on chrome window B's browser element [actionid 26], which focuses content window proxy b [7f173d1f83e0] in the content process.
7. The queued WindowRaised() records chrome window A as the active window and attempts to focus content window proxy a, but content process changes are dropped due to stale actionid 25.

Comment 1

[Karl Tomlinson (:karlt)]

Perhaps, there may exist an issue here that element focus changes are taking priority over active OS window changes with stale action IDs.

However, I don't know whether that could occur in practice without "focusmanager.testmode", given that active OS window changes usually GenerateFocusActionId() at the time of the WindowRaised() call.
https://treeherder.mozilla.org/jobs?repo=try&revision=138fd1fb15d3e0513b5a02b203161f1ee27fc1b2

Comment 2

[Karl Tomlinson (:karlt)]

Attachment: Bug 1733301 generate action ID for focusmanager.testmode WindowRaised() at time of call r?hsivonen

for consistency with OS-triggered calls
https://searchfox.org/mozilla-central/rev/b022ae1fc071ad7a29f64f281bc19b7b093df538/xpfe/appshell/AppWindow.cpp#3005
and so that interleaved element-focus actions don't make the active toplevel
window change notification (and its associated content window focus changes)
stale.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b983111f779f
generate action ID for focusmanager.testmode WindowRaised() at time of call r=hsivonen

Comment 4

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/b983111f779f

Comment 5

[Marco Castelluccio [:marco]]

Set release status flags based on info from the regressing bug 1618386