STR: 1. Open Gmail 2. Click "Compose" 3. Write some text in message body with IME enabled (e.g. あ) 4. Alt+Tab to another non-Firefox window. 5. Alt+Tab back to the Firefox window with Gmail. 6. Press 'a' in the keyboard. Expected results: IME is still active and, e.g. あ is produced. Actual results: The IME is disabled (in the taskbar an 'x' is shown') and hence 'a' is produced. Furthermore, it is not possible to activate to the IME be pressing the 半角/全角漢字 button. If I click the text area again, however, the IME is enabled and activated.

Regression range: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=52d81035277456e1efd1f218daa9147e57546f8c&tochange=3bdc87d4e53823781ac103930c6a06f2f0c95f80

STR for me (which probably is but might not be the exact same underlying issue): 1. Have IME disabled. 2. Focus an input / textarea. 3. Activate IME, leaving the input / textarea focused. (For example by pressing a keyboard shortcut to activate IME.) 4. Type some text. Expected results: IME handles input. Actual results: IME does not handle input.

Thanks for comment 0 for STR and :haycam for the pointer. I can produce this bug on Mac too! The actual result is a slightly different; I am not sure if this is another bug. STR: 1. Open Gmail 2. Click "Compose" 3. Write some text in message body with IME enabled (e.g. ㄆ) 4. Alt+Tab to another non-Firefox window. 5. Alt+Tab back to the Firefox window with Gmail. 6. Press 'q' in the keyboard. Expected results: IME is still active and, e.g. ㄆ is produced. Actual results: The IME is disabled (*but* the menu icon still shows it being active) and hence 'q' is produced. Furthermore, it is not possible to activate to the IME by Cmd+space. The menu icon will switch the IME on-and-off but it will never become active. The only workaround I've found so far is moving the focus to address bar and back.

(nit: the window-switching hot key on Mac is obviously Cmd+tab, instead of Alt-tab)

[Tracking Requested - why for this release]: Given that we are approaching beta merge day, it's definitely a bug we are concerning and worth tracking in coming beta release.

Surprisingly, this is really long standing bug! We were just lucky because we have never met the condition.

Comment on attachment 8889892 [details] Bug 1381732 - IMEStateManager::OnChangeFocusInternal() shouldn't set IME state when focus is not being changed, input context of the widget was already set by a remote process and our process is being activated https://reviewboard.mozilla.org/r/160952/#review166564

Pushed by masayuki@d-toybox.com: https://hg.mozilla.org/integration/autoland/rev/5886dae0a324 IMEStateManager::OnChangeFocusInternal() shouldn't set IME state when focus is not being changed, input context of the widget was already set by a remote process and our process is being activated r=m_kato

(In reply to Masayuki Nakano [:masayuki] (JST, +0900) from comment #6) > Surprisingly, this is really long standing bug! We were just lucky because > we have never met the condition. That's true and to me it happened intermittently so that I don't have STR with further help. Thanks for fixing this bug!

I'm still seeing this in today's nightly based on https://hg.mozilla.org/mozilla-central/rev/2fba314d7de77ad8ab693a2ea0112c0cda5dd564 Is that expected?

(In reply to Brian Birtles (:birtles, away 31 July~7 Aug) from comment #12) > I'm still seeing this in today's nightly based on > https://hg.mozilla.org/mozilla-central/rev/ > 2fba314d7de77ad8ab693a2ea0112c0cda5dd564 > > Is that expected? Oh, that's odd. I can reproduce it only with MS-IME for Japanese, not reproduce with ATOK nor Google Japanese IME. It might be related to disassociating IMM context only when active IME is MS-IME??

Oh, my guess is correct. Brian, please turn "intl.tsf.hack.ms_japanese_ime.do_not_associate_imc_on_win10" to false and restart your Firefox. I'll remove the hack from Gecko since it failed to prevent crash of MS-IME and also caused another regression.

I tried switching that pref to false and restarting but I still see the bug. I am using MS-IME.

Oh, really? That's odd... I'll investigate it soon.