1449813 - Infinite cascade of tabs attempting to open an Intel data sheet

Status: RESOLVED DUPLICATE of bug 218257

(Firefox :: File Handling, defect)

Description

[ncoghlan]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0
Build ID: 20180323154952

Steps to reproduce:

1. Visit https://www.intel.com.au/content/www/au/en/intelligent-systems/queens-bay/platform-controller-hub-eg20t-datasheet.html
2. Click the "Download PDF" button
3. Choose to open the PDF in Firefox (downloading to disk works fine)


Actual results:

Firefox starts opening an infinite cascade of empty tabs (with a file:// URL presumably referring to the downloaded file) attempting to load the PDF. Even closing the affected window doesn't stop it - the problem transfers itself to the next active Firefox window and starts opening empty tabs there.


Expected results:

Ideally, it would have just opened the PDF in the Firefox PDF viewer (which is what Edge did in this case).

In the event that this was an add-on triggered problem, then I'd have expected  Firefox to detect the neverending cascade of "New tab" requests for the same URL and stop them (similar to the way it detects server side redirect loops).

Comment 1

[ncoghlan]

As an additional data point: if I use "Open With -> Firefox" in Windows File Explorer to attempt to view the PDF, then instead of loading the PDF viewer plugin, it prompts me to choose a different application to handle the file. If I choose Firefox again at that point, it opens a new window with a new prompt.

So it seems that may be the underlying trigger, and then the "infinite cascade" behaviour arises from that prompt being automatically bypassed.

Checking about:config shows "plugin.disable_full_page_plugin_for_types;application/pdf", if that's potentially relevant. (I tried removing that without any noticeable effect, but I also didn't restart Firefox after changing the setting).

Comment 2

[Gingerbread Man]

1. Enter about:support into the location bar.
2. Click the Open Folder button. This opens a file manager window with your Firefox profile folder.
3. Exit Firefox.
4. Back in the file manager window, delete the handlers.json file.


If you get a "What should Firefox do with this file?" dialog and you choose to open with Firefox, that will create an infinite loop. That dialog is for external applications only, and you're not supposed to be able to pick Firefox there [1]. To do that safely, use the Open in Browser extension [2].

The only way to view PDFs in Firefox is to set the action to "Preview in Firefox" in about:preferences. However, servers can still trigger the "What should Firefox do with this file?" dialog, usually by sending the Content-Disposition: attachment header. One way to get around that is the Bypass Forced Download extension [3]. Less commonly, they can also fail to correctly identify the file type by sending Content-Type: application/octet-stream. Extensions like Header Editor can override that [4].


[1] Bug 218257
[2] https://addons.mozilla.org/firefox/addon/open-in-browser/
[3] https://addons.mozilla.org/firefox/addon/bypass-forced-download/
[4] https://addons.mozilla.org/firefox/addon/header-editor/