This bug happens since https://codereview.chromium.org/2189513004 due to the change in Document::didAssociateFormControl()

Browser learns about a password form in 3 cases:
- Document::FinishedParsing() causes FinishDocumentLoad event. All the forms are sent to the browser.
- WebFrameClient::DidFinishLoad(). Intended mostly for the successful submission detection and not autofill. All the visible forms are sent.
- Document::DidAssociateFormControl causes OnDynamicFormsSeen event. All the forms are sent.

https://codereview.chromium.org/2189513004 introduced a check that the dynamic forms are not sent if the page is still loading. That prevented unnecessary IPC messages. The bug is happening when a form is detected between FinishDocumentLoad and DidFinishLoad events. There is no problem for a visible form because it's reported in DidFinishLoad(). However, if the form is invisible then it's entirely skipped. Later some user action makes the form visible but it's completely ignored by Chrome.

The correct way is to report all the dynamic forms after Document::FinishedParsing() event.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5e87893ed5a96e6ab36de9280c8e647f7f8eb65b

commit 5e87893ed5a96e6ab36de9280c8e647f7f8eb65b
Author: vasilii <vasilii@chromium.org>
Date: Fri Apr 21 08:46:34 2017

Notify PasswordAutofillAgent about dynamic forms after the document was parsed.

Previosly the form were reported after the document and all the resources were loaded.

BUG= 713645 

Review-Url: https://codereview.chromium.org/2832473004
Cr-Commit-Position: refs/heads/master@{#466289}

[modify] https://crrev.com/5e87893ed5a96e6ab36de9280c8e647f7f8eb65b/chrome/browser/password_manager/password_manager_browsertest.cc
[modify] https://crrev.com/5e87893ed5a96e6ab36de9280c8e647f7f8eb65b/chrome/test/data/password/between_parsing_and_rendering.html
[modify] https://crrev.com/5e87893ed5a96e6ab36de9280c8e647f7f8eb65b/third_party/WebKit/Source/core/dom/Document.cpp

This sounds impactful. Should we merge this to M59?

I planned to do this.

I want to merge r466289 to M59.

Your change meets the bar and is auto-approved for M59. Please go ahead and merge the CL to branch 3071 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), gkihumba@(ChromeOS), Abdul Syed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b738d0182104f66bdcb224dd2a90663b1446e537

commit b738d0182104f66bdcb224dd2a90663b1446e537
Author: Vasilii Sukhanov <vasilii@chromium.org>
Date: Mon Apr 24 12:32:45 2017

Notify PasswordAutofillAgent about dynamic forms after the document was parsed.

Previosly the form were reported after the document and all the resources were loaded.

BUG= 713645 

Review-Url: https://codereview.chromium.org/2832473004
Cr-Commit-Position: refs/heads/master@{#466289}
(cherry picked from commit 5e87893ed5a96e6ab36de9280c8e647f7f8eb65b)

Review-Url: https://codereview.chromium.org/2835933003 .
Cr-Commit-Position: refs/branch-heads/3071@{#161}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}

[modify] https://crrev.com/b738d0182104f66bdcb224dd2a90663b1446e537/chrome/browser/password_manager/password_manager_browsertest.cc
[modify] https://crrev.com/b738d0182104f66bdcb224dd2a90663b1446e537/chrome/test/data/password/between_parsing_and_rendering.html
[modify] https://crrev.com/b738d0182104f66bdcb224dd2a90663b1446e537/third_party/WebKit/Source/core/dom/Document.cpp

Verified this issue on Windows-10, Ubuntu 14.04 and Mac OS 10.12.4 using chrome latest Dev #59.0.3071.25 by following steps mentioned in the original comment. Observed saved credential is offered in the drop down as expected. Hence adding TE-Verified label.

Deleted: 713645.ogv 1.5 MB

	713645.ogv 1.5 MB View Download

I'm still seeing the same issue on
(1) MacPro
macOS 10.12.4
Chrome Canary Version 60.0.3080.5 (Official Build) canary (64-bit)
(2) iMac
macOS 10.12.4
Chrome Canary Version 60.0.3080.5 (Official Build) canary (64-bit)

Steps to reproduce:
(1) Navigate to https://credential-management-sample.appspot.com/
(2) Register/save a credential with Chrome
(3) Load again, sign out (if necessary), try to sign in using the password form (dismiss the account chooser)

I'm expecting to see both email field and password field are autofilled with yellow-ish background color.
But what I'm actually seeing empty fields. By locating cursor I see email candidates for email field, password suggestion for password field. See attached image.

Deleted: Screen Shot 2017-04-26 at 19.15.04.png 25.1 KB

	Screen Shot 2017-04-26 at 19.15.04.png 25.1 KB View Download

Deleted: Screen Shot 2017-04-26 at 19.15.11.png 18.9 KB

	Screen Shot 2017-04-26 at 19.15.11.png 18.9 KB View Download

Deleted: Screen Shot 2017-04-26 at 19.15.16.png 18.3 KB

	Screen Shot 2017-04-26 at 19.15.16.png 18.3 KB View Download

I found the culprit, the following is the technical explanation:

Credentials API saves credentials without action (and it looks ok), but when Password Manager decides whether to fill on load or postpone until the user clicks it verifies whether actions of the current form the same to the action of a saved form and in case when HTML form has no action, current url is taken.
So here actions are different.The code lives here https://cs.chromium.org/chromium/src/components/password_manager/core/browser/password_form_manager.cc?sq=package:chromium&l=635 observed_form_.action.GetWithEmptyPath() !=
            preferred_match_->action.GetWithEmptyPath()

The solution is to remove this check, since it's obsolete.

Less technical, consequences of this bug:
1.All credentials API saved credentials are filled only on account select
2.Credentials saved on some sign-up forms are filled only on account select on sign-in forms.

We will fix this.

agektmr@, is password filled when you choose "agektmr@gmail.com"? I didn't promise that it's autofilled on load :)

If it doesn't fill the password then I need your chrome://password-manager-internals

No. How can I help with chrome://password-manager-internals ?

Open chrome://password-manager-internals before navigating to the testing site.
After completing the test, upload the content of password-manager-internals here.

Captured password manager logs are listed below. Logs are cleared and no longer captured when all password-manager-internals pages are closed.
Message: PasswordAutofillAgent::DidStartProvisionalLoad 
The new state of the UI: 0
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://credential-management-sample.appspot.com/ 
Number of all forms: 0
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://staticxx.facebook.com/ 
Number of all forms: 0
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://accounts.google.com/ 
Message: Webpage is empty 
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: true
Security origin: https://accounts.google.com/ 
Message: Webpage is empty 
CM API get credentials: origin=https://credential-management-sample.appspot.com/, zero_click_only=1, federations=https://accounts.google.com/, https://www.facebook.com/,
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
CM API send a credential: origin=https://credential-management-sample.appspot.com/, CredentialType=CredentialType::CREDENTIAL_TYPE_EMPTY
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: true
Security origin: https://staticxx.facebook.com/ 
Number of all forms: 0
Some control elements not associated to a form element are visible: false
Message: PasswordManager::CreatePendingLoginManagers 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Number of pending login managers (before): 0
Number of pending login managers (after): 0
Message: PasswordManager::OnPasswordFormsRendered 
Message: PasswordManager::CanProvisionalManagerSave 
Message: No provisional save manager 
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: true
Security origin: https://credential-management-sample.appspot.com/ 
Number of all forms: 2
Form found on page: {
Action : https://credential-management-sample.appspot.com/ ,
Form name or ID : 
}
Form is visible: false
Form found on page: {
Action : https://credential-management-sample.appspot.com/ ,
Form name or ID : 
}
Form is visible: true
Form is a password form: {
Action : https://credential-management-sample.appspot.com/ ,
New password element : password ,
Origin : https://credential-management-sample.appspot.com/ ,
PSL match : false,
Password element : ,
Password generated : false,
Scheme : HTML ,
Signon realm : https://credential-management-sample.appspot.com/ ,
Times used : 0,
Username element : email 
}
Some control elements not associated to a form element are visible: false
Message: PasswordManager::CreatePendingLoginManagers 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Number of pending login managers (before): 0
Adding manager for form: {
Signature of form: 7658152542967986450
Signon realm: https://credential-management-sample.appspot.com/
Origin: https://credential-management-sample.appspot.com/
Action: https://credential-management-sample.appspot.com/
Form name: reg-form
Form fields: 
name: 3489289364, text, name
email: 1029417091, email, username_email
password: 2051817934, password, new-password
}
Message: FormFetcherImpl::Fetch 
FormFetcherImpl::state_: 1
Number of pending login managers (after): 1
Message: PasswordManager::OnPasswordFormsRendered 
Message: PasswordManager::CanProvisionalManagerSave 
Message: No provisional save manager 
Generation possible account creation forms: 2
Message: Generation: no non-blacklisted confirmation 
Message: Generation: no non-blacklisted confirmation 
Message: FormFetcherImpl::OnGetPasswordStoreResults 
Number of results from the password store: 1
Message: PasswordFormManager::ProcessMatches 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Message: Generation disabled: custom passphrase 
Message: PasswordManager::Autofill 
wait_for_username: true
The new state of the UI: 3
Message: PasswordAutofillAgent::OnFillPasswordForm 
ambiguous_or_empty_names: false
Number of potential forms to fill: 0
form_data's wait_for_username: true
CM API get credentials: origin=https://credential-management-sample.appspot.com/, zero_click_only=0, federations=https://accounts.google.com/, https://www.facebook.com/,
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
The new state of the UI: 4
CM API send a credential: origin=https://credential-management-sample.appspot.com/, CredentialType=CredentialType::CREDENTIAL_TYPE_EMPTY
The new state of the UI: 3

I know the bug! You reproduced it because the page loaded slowly on your machine.
This is what happened on my machine:
- the page was parsed.
- the dynamic sign-in form was detected and Document::DidAssociateFormControl starts the timer for 0.3 sec.
- the page fully loaded.
- the timer fired and the renderer processed and sent the sign-in form to browser.

Here is what's happened on your machine:
- the page was parsed.
- the dynamic sign-in form was detected and Document::DidAssociateFormControl starts the timer for 0.3 sec.
- the timer fired and AutofillAgent::DidAssociateFormControlsDynamically() did nothing because it's still loading.
- the page fully loaded.

I know it because even the autosign-in call from the API happened before the page fully loaded. So the bug is in AutofillAgent::DidAssociateFormControlsDynamically().

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/31ba8c6c5838fd6e65f3e341cfb5af0736186dc3

commit 31ba8c6c5838fd6e65f3e341cfb5af0736186dc3
Author: vasilii <vasilii@chromium.org>
Date: Fri Apr 28 21:35:08 2017

Password manager should autofill a dynamic form added and processed before the page was loaded.

Currently AutofillAgent::DidAssociateFormControlsDynamically ignores the notification if the frame isn't loaded. That makes no sense because the page may never be loaded due to some slow resource. Even if it will, password autofill shouldn't wait for the page load event. It's needed primarily for the successful submission detection.

BUG= 713645 

Review-Url: https://codereview.chromium.org/2849653003
Cr-Commit-Position: refs/heads/master@{#468136}

[modify] https://crrev.com/31ba8c6c5838fd6e65f3e341cfb5af0736186dc3/chrome/browser/password_manager/password_manager_browsertest.cc
[add] https://crrev.com/31ba8c6c5838fd6e65f3e341cfb5af0736186dc3/chrome/test/data/password/infinite_password_form.html
[modify] https://crrev.com/31ba8c6c5838fd6e65f3e341cfb5af0736186dc3/components/autofill/content/renderer/autofill_agent.cc

I want to merge r468136 to M59. It fixes an important autofill problem for slow networks.

Your change meets the bar and is auto-approved for M59. Please go ahead and merge the CL to branch 3071 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), gkihumba@(ChromeOS), Abdul Syed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8da0ab3664c77f527e2cc845c5349bf37f79f959

commit 8da0ab3664c77f527e2cc845c5349bf37f79f959
Author: Vasilii Sukhanov <vasilii@chromium.org>
Date: Tue May 02 10:39:53 2017

Password manager should autofill a dynamic form added and processed before the page was loaded.

Currently AutofillAgent::DidAssociateFormControlsDynamically ignores the notification if the frame isn't loaded. That makes no sense because the page may never be loaded due to some slow resource. Even if it will, password autofill shouldn't wait for the page load event. It's needed primarily for the successful submission detection.

BUG= 713645 

Review-Url: https://codereview.chromium.org/2849653003
Cr-Commit-Position: refs/heads/master@{#468136}
(cherry picked from commit 31ba8c6c5838fd6e65f3e341cfb5af0736186dc3)

Review-Url: https://codereview.chromium.org/2854773003 .
Cr-Commit-Position: refs/branch-heads/3071@{#342}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}

[modify] https://crrev.com/8da0ab3664c77f527e2cc845c5349bf37f79f959/chrome/browser/password_manager/password_manager_browsertest.cc
[add] https://crrev.com/8da0ab3664c77f527e2cc845c5349bf37f79f959/chrome/test/data/password/infinite_password_form.html
[modify] https://crrev.com/8da0ab3664c77f527e2cc845c5349bf37f79f959/components/autofill/content/renderer/autofill_agent.cc

Rechecked the issue on chrome version 59.0.3071.36 on MAC 10.12.4, Ubuntu 14.04, Windows 10 as per the steps mentioned in comment#9. Fix is working as intended. Able to see the email address and password autofilled with yellow color in background. Screen Shot attached.

Adding TE-verified labels.

Thanks.!

Deleted: Screen Shot 2017-05-03 at 4.51.39 PM.png 149 KB

	Screen Shot 2017-05-03 at 4.51.39 PM.png 149 KB View Download

Note that the latest fix affects the slow networks.

I can still reproduce this issue on stable 59.0.3071.61 on MAC and dev 60.0.3102.0 on MAC on a wifi connection.

Here is the chrome://password-manager-internals log from pressing the sign-in button and declining the CM API bubble:

Captured password manager logs are listed below. Logs are cleared and no longer captured when all password-manager-internals pages are closed.
CM API get credentials: origin=https://credential-management-sample.appspot.com/, zero_click_only=0, federations=https://accounts.google.com/, https://www.facebook.com/,
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
The new state of the UI: 4
CM API send a credential: origin=https://credential-management-sample.appspot.com/, CredentialType=CredentialType::CREDENTIAL_TYPE_EMPTY
The new state of the UI: 3

I need the full log starting before the page loading.

Not reproducible on the office network.
- What kind of network did you use?
- Was the password offered in the drop-down when the username field is selected? In other words, is the observed behaviour equivalent to that in Comment #9?

Steps to reproduce:
1) Go to https://credential-management-sample.appspot.com/
2) Fill form, click on register, save credential
3) Log out
4) Load chrome://password-manager-internals
5) Refresh https://credential-management-sample.appspot.com/
6) Click login
7) Observe popup dialog with account and decline
8) Observe dialog showing up on the website with non-filled fields

Here are the logs starting at step 4

Captured password manager logs are listed below. Logs are cleared and no longer captured when all password-manager-internals pages are closed.
Message: PasswordAutofillAgent::DidStartProvisionalLoad 
The new state of the UI: 0
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://credential-management-sample.appspot.com/ 
Number of all forms: 0
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://staticxx.facebook.com/ 
Number of all forms: 0
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: true
Security origin: https://staticxx.facebook.com/ 
Number of all forms: 0
Some control elements not associated to a form element are visible: false
Message: PasswordManager::CreatePendingLoginManagers 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Number of pending login managers (before): 0
Number of pending login managers (after): 0
Message: PasswordManager::OnPasswordFormsRendered 
Message: PasswordManager::CanProvisionalManagerSave 
Message: No provisional save manager 
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://accounts.google.com/ 
Message: Webpage is empty 
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: true
Security origin: https://accounts.google.com/ 
Message: Webpage is empty 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Message: Generation disabled: no sync 
Server predictions: {
Signature of form: 9098940619517107511
Origin: https://credential-management-sample.appspot.com/
Action: https://credential-management-sample.appspot.com/
Form fields: 
email: 1029417091, email, username
password: 2051817934, password, current-password
}
Server predictions: {
Signature of form: 7658152542967986450
Origin: https://credential-management-sample.appspot.com/
Action: https://credential-management-sample.appspot.com/
Form fields: 
name: 3489289364, text, name, SERVER_PREDICTION: HTML_TYPE_NAME
email: 1029417091, email, username_email, SERVER_PREDICTION: EMAIL_ADDRESS
password: 2051817934, password, new-password
}
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: false
Security origin: https://credential-management-sample.appspot.com/ 
Number of all forms: 2
Form is a password form: {
Action : https://credential-management-sample.appspot.com/ ,
New password element : ,
Origin : https://credential-management-sample.appspot.com/ ,
PSL match : false,
Password element : password ,
Password generated : false,
Scheme : HTML ,
Signon realm : https://credential-management-sample.appspot.com/ ,
Times used : 0,
Username element : email 
}
Form is a password form: {
Action : https://credential-management-sample.appspot.com/ ,
New password element : password ,
Origin : https://credential-management-sample.appspot.com/ ,
PSL match : false,
Password element : ,
Password generated : false,
Scheme : HTML ,
Signon realm : https://credential-management-sample.appspot.com/ ,
Times used : 0,
Username element : email 
}
Message: PasswordManager::CreatePendingLoginManagers 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Number of pending login managers (before): 0
Adding manager for form: {
Signature of form: 9098940619517107511
Signon realm: https://credential-management-sample.appspot.com/
Origin: https://credential-management-sample.appspot.com/
Action: https://credential-management-sample.appspot.com/
Form name: signin-form
Form fields: 
email: 1029417091, email, username
password: 2051817934, password, current-password
}
Message: FormFetcherImpl::Fetch 
FormFetcherImpl::state_: 1
Adding manager for form: {
Signature of form: 7658152542967986450
Signon realm: https://credential-management-sample.appspot.com/
Origin: https://credential-management-sample.appspot.com/
Action: https://credential-management-sample.appspot.com/
Form name: reg-form
Form fields: 
name: 3489289364, text, name
email: 1029417091, email, username_email
password: 2051817934, password, new-password
}
Message: FormFetcherImpl::Fetch 
FormFetcherImpl::state_: 1
Number of pending login managers (after): 2
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Generation possible account creation forms: 2
Message: Generation: no non-blacklisted confirmation 
Message: Generation: no non-blacklisted confirmation 
Message: PasswordAutofillAgent::SendPasswordForms 
only_visible: true
Security origin: https://credential-management-sample.appspot.com/ 
Number of all forms: 2
Form found on page: {
Action : https://credential-management-sample.appspot.com/ ,
Form name or ID : 
}
Form is visible: false
Form found on page: {
Action : https://credential-management-sample.appspot.com/ ,
Form name or ID : 
}
Form is visible: true
Form is a password form: {
Action : https://credential-management-sample.appspot.com/ ,
New password element : password ,
Origin : https://credential-management-sample.appspot.com/ ,
PSL match : false,
Password element : ,
Password generated : false,
Scheme : HTML ,
Signon realm : https://credential-management-sample.appspot.com/ ,
Times used : 0,
Username element : email 
}
Some control elements not associated to a form element are visible: false
Message: PasswordManager::CreatePendingLoginManagers 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Number of pending login managers (before): 2
Number of pending login managers (after): 2
Message: PasswordManager::OnPasswordFormsRendered 
Message: PasswordManager::CanProvisionalManagerSave 
Message: No provisional save manager 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Generation possible account creation forms: 4
Message: Generation: no non-blacklisted confirmation 
Message: Generation: no non-blacklisted confirmation 
Message: Generation: no non-blacklisted confirmation 
Message: Generation: no non-blacklisted confirmation 
Message: FormFetcherImpl::OnGetPasswordStoreResults 
Number of results from the password store: 1
Message: PasswordFormManager::ProcessMatches 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Message: Generation disabled: no sync 
Message: PasswordManager::Autofill 
wait_for_username: true
The new state of the UI: 3
Message: FormFetcherImpl::OnGetPasswordStoreResults 
Number of results from the password store: 1
Message: PasswordFormManager::ProcessMatches 
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
Message: Generation disabled: no sync 
Message: PasswordManager::Autofill 
wait_for_username: true
The new state of the UI: 3
Message: PasswordAutofillAgent::OnFillPasswordForm 
ambiguous_or_empty_names: false
Number of potential forms to fill: 1
form_data's wait_for_username: true
form_contains_fillable_username_field: true
username_field_name empty: false
password_field_name empty: false
Message: PasswordAutofillAgent::OnFillPasswordForm 
ambiguous_or_empty_names: false
Number of potential forms to fill: 0
form_data's wait_for_username: true
CM API get credentials: origin=https://credential-management-sample.appspot.com/, zero_click_only=1, federations=https://accounts.google.com/, https://www.facebook.com/,
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
CM API send a credential: origin=https://credential-management-sample.appspot.com/, CredentialType=CredentialType::CREDENTIAL_TYPE_EMPTY
CM API get credentials: origin=https://credential-management-sample.appspot.com/, zero_click_only=0, federations=https://accounts.google.com/, https://www.facebook.com/,
SSL errors present: false
IsPasswordManagementEnabledForCurrentPage: true
SSL errors present: false
The new state of the UI: 4
CM API send a credential: origin=https://credential-management-sample.appspot.com/, CredentialType=CredentialType::CREDENTIAL_TYPE_EMPTY
The new state of the UI: 3

The question is if you get "fill on account select" behavior after step #8 or not?
I know that it's not autofilled and it was never claimed in this bug.

The log above says that Chrome saw the sign-in form and created PasswordFormManager for it.

This time, I did get fill on account select. I think last time, I did not. Hm... I cannot reproduce it anymore.

Unlike the log from Comment 16, the log from Comment 28 clearly contains the sign-in form. A similar log I get locally on Canary where everything works.
I close the bug until some new data is available.