Default behavior of PDF documents

[Tushman]

This is a heads up warning (notice) to all Firefox users. Starting with version 78, Mozilla has decided to make Firefox the default handler for all PDF documents. I found this out after I did a clean upgrade from v77 to v78. After upgrading, I was doing something on my computer and needed to open up a PDF file that had previously saved on my PC. I couldn't find it. Turns out I was looking for the wrong icon because Firefox had taken control.

Of course it is very easy to change the default application back to whatever you were using before - but why the hell Mozilla has decided to do this in its infinite wisdom is beyond me.

I was using v78 for a while and then I was notified about a new update. So i did a minor upgrade from v78 to v78.0.1 - the PDF default handler got changed back to Firefox ONCE AGAIN. This is totally ridiculous behavior of Mozilla. This is the year 2020 Mozilla, I don't need you to change my PDF file association!

[skuddle]

I whole-heartedly agree!

[BobbyPhoenix]

After I updated the next time I tried to open a PDF the selection box showed with Adobe Reader DC as the selected choice, and all the others below it. The box to check for "Always use this" was unchecked. All I had to do was recheck it, and the PDF opened with Adobe. Tried another one after that, and no selection needed. Opened right away with Adobe. This happened on my three PCs. I guess Mozilla has some trigger to remove the default selection that was used. I don't agree with that, but a simple enough option to get it back to what I wanted.

[WaltS48]

Sounds like a bug to me. Anyone file a bug report?

[James]

Firefox 78.0 and later releases offers a choice to open PDF files that would normally be saved or opened in an external application in Firefox.

You can disable this by setting this preference to false in about:config

browser.helperApps.showOpenOptionForPdfJS to false

[Grumpus]

This seems out of sorts. The panel which opened up would allow a choice of save or view and also gave specs on the pdf, principally size.
It states the options can be set in the Applications tab but once you set a file type to open or save it does not allow the option again.
What seems unsettling to me is the fact the pdf displays without control even with the preference set to false.

[mightyglydd]

I don't agree with that, but a simple enough option to get it back to what I wanted.

Yep simple enough.
FWIW: I have no idea if it makes any difference but I also Set Win 10 'Chose default App by file type' (PDF) to in my case Sumatra.

[Tushman]

Firefox 78.0 and later releases offers a choice to open PDF files that would normally be saved or opened in an external application in Firefox.

There is no notice or "choice" given during the installation. It does whatever it wants to do and users are not made aware of the file association change until after it's all said & done.

[mightyglydd]

Yep, complete twaddle, as is recommending screwing around in about:config.
99.9% of users are better off not knowing it exists.

[Grumpus]

@James - tried changing browser.helperApps.showOpenOptionForPdfJS to false and it does nothing on another Linux Mint system.
Works on an older Linux Mint system with the same 78.01 Firefox.
Also with the other system was able to function initially but (my fault) after checking the handle all files like this in the future block, now it only downloads.
Haven't found a way to reverse it.
Also why would edge be part of the process in a Linux install for pdfjs?