1997039 - Firefox ends up with a blank tab (and no app-launch or prompt) when user taps a Google docs/sheet link from external app (e.g. Gmail) that has "&ca=1" in the URL

Status: NEW

(Firefox for Android :: App Links, defect)

Description

[Daniel Holbert [:dholbert]]

Steps to reproduce

1. Make sure you've got the Firefox Nightly "open links in Apps" setting set to either "Ask" or "Always" (this bug has exact same results with both of those values), and that it's your default browser.
2. Email yourself this link: https://docs.google.com/spreadsheets/d/1LLo3bT8shAgoRwGk3rDurfKigIcgRZKFKpQNPagkI-s/edit?usp=sharing_eip_se_dm&ts=6901596a&ca=1
   (note: the "&ca=1" is important - without that, the doc just directly opens in the native Docs/Sheets app. It seems that "&ca=1" tells the Docs/Sheets app to decline-to-open-the-URL and hand it off to the default browser.)
3. Tap that^ link in your email.

Expected behavior

New tab in Firefox Nightly, showing the sheet.
(Or, Firefox should launch / ask-to-launch the Android "Sheets" app).
(Clarifying expectations: we definitely should not ask to launch in this case, because as I've later discovered, it's the Google Sheets app itself that's asking us to load the URL. Gmail seems to invoke Sheets, which then decides not to open the URL and invokes the default browser instead.)

Actual behavior

New tab in Firefox Nightly, with the correct URL, but blank content area.

Device information

• Firefox version: 146.0a1 2025-10-28
• Android device model: Pixel 6a, Pixel 10 Pro XL
• Android OS version: 16

Any additional information?

I narrowed the regression range to:
Last good Nightly: 2025-07-01
First bad Nightly: 2025-07-02
This is the same regression range mentioned at the end of bug 1983949 comment 1; I'm assuming this had the same regressor, bug 1974569 (but unlike other regressions from that bug, this one's still not fixed)

Comment 1

[Daniel Holbert [:dholbert]]

Note:

• Chrome gives EXPECTED RESULTS (if I set Chrome as my default browser, they just open the link directly in the browser)
• I ran across this bug in the wild when someone shared a Google Sheet with me, using an email address that doesn't have an associated Google account. The email that Google Sheets generated & sent to that email included a docs.google.com link with this special &ca=1 token in the document URL; and apparently that's a clue to the native Sheets/Docs app to hand off the URL to the browser. (If I instead share a Google Sheet to a Gmail email-address, then I instead get an email with a doc-URL that lacks this ca=1 token; and when I tap the link in Gmail, it just directly opens in the Google Sheets app without invoking the browser at all.)

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screencast of bug

Comment 3

[Daniel Holbert [:dholbert]]

Note: after you've hit the bug, you can work around it by reloading the blank tab -- then the Google Sheet loads properly (in the browser).

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

:royang, since you are the author of the regressor, bug 1974569, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 5

[Daniel Holbert [:dholbert]]

Alternate STR:

1. Make sure you've got the Firefox Nightly "open links in Apps" setting set to either "Ask" or "Always" (this bug has exact same results with both of those values), and that it's your default browser.
2. Open this bugzilla page in Firefox Nightly.
3. Tap the docs.google.com URL in comment 0, which is: https://docs.google.com/spreadsheets/d/1LLo3bT8shAgoRwGk3rDurfKigIcgRZKFKpQNPagkI-s/edit?usp=sharing_eip_se_dm&ts=6901596a&ca=1
4. If prompted to open an external app, click to allow.

EXPECTED RESULTS:
New tab in Firefox showing the sheet (because Google Sheets happens to decline to load this URL, and it hands it back to the default browser, which is us).

ACTUAL RESULTS:
New blank tab in Firefox, with the correct URL but empty content area.

Comment 6

[Daniel Holbert [:dholbert]]

Actually, sorry, comment 5's STR don't repro the bug, on my second attempt (I could've sworn they did on my first attempt but I may have done something different. In any case, I've marked comment 5 as obsolete to auto-hide it.

But: I can still repro the bug if I do a variation on comment 5, where I tap the link in another browser (e.g. Chrome) -- basically having Chrome serve the role of the Gmail app in my original comment 0 STR.

ALTERNATE STR (tapping link in Chrome instead of Gmail):

1. Make sure you've got the Firefox Nightly "open links in Apps" setting set to either "Ask" or "Always" (this bug has exact same results with both of those values), and that it's your default browser.
2. Open this bugzilla page in Chrome.
3. Tap the docs.google.com URL in comment 0, which is: https://docs.google.com/spreadsheets/d/1LLo3bT8shAgoRwGk3rDurfKigIcgRZKFKpQNPagkI-s/edit?usp=sharing_eip_se_dm&ts=6901596a&ca=1

EXPECTED RESULTS:
New tab in Firefox Nightly showing the sheet (because Google Sheets happens to decline to load this URL, and it hands it back to the default browser, which is us).

ACTUAL RESULTS:
New blank tab in Firefox Nightly, with the correct URL but empty content area.

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1974569