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Firefox insists on opening files from local temp dir, discarding URLs

  • 5 replies
  • 1 has this problem
  • 3 views
  • Last reply by Nils

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My question is a blend of these two previous questions:

https://support.mozilla.org/en-US/questions/1303566 https://support.mozilla.org/en-US/questions/1277388

I have a bunch of open tabs which used to simply contain pdf documents, opened in the Firefor pdf viewer, with the file URL in the address bar rather than a local temp dir address. This behaviour however changed with a recent update (I'm on 82.0b5), and now when I reload those old tabs, I get prompted for a download, and a new tab is opened following the download with a local temp dir replacing the URL. As all these files previously opened just fine in the FF preview with the URL present, this is unlikely to be related to whether the server sends files as "application/pdf" or otherwise, as the same files have changed behaviour, and it is unlikely that a bunch of servers changed the way they send files at the same time.

Further, the answer to the second question above proposed to select "Preview in Firefox" to get around this, however this option doesn't seem to exist anymore.

Is this a known behaviour change in FF82? If so, is there a way to get the old behaviour back?

My question is a blend of these two previous questions: https://support.mozilla.org/en-US/questions/1303566 https://support.mozilla.org/en-US/questions/1277388 I have a bunch of open tabs which used to simply contain pdf documents, opened in the Firefor pdf viewer, with the file URL in the address bar rather than a local temp dir address. This behaviour however changed with a recent update (I'm on 82.0b5), and now when I reload those old tabs, I get prompted for a download, and a new tab is opened following the download with a local temp dir replacing the URL. As all these files previously opened just fine in the FF preview with the URL present, this is unlikely to be related to whether the server sends files as "application/pdf" or otherwise, as the same files have changed behaviour, and it is unlikely that a bunch of servers changed the way they send files at the same time. Further, the answer to the second question above proposed to select "Preview in Firefox" to get around this, however this option doesn't seem to exist anymore. Is this a known behaviour change in FF82? If so, is there a way to get the old behaviour back?

All Replies (5)

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They have changed the "Preview in Firefox" label to "Open in Firefox".

If you use the "Open in Firefox" choice in the open with (download) dialog then the file is saved to the temp folder like also happens if you open the file in an external application. This makes that you see a link to the temp folder and lose the original internet URL to this file.

With what content type are these PDF files send if you check this in the Web Console ?

Firefox 78+ releases offer a choice to open PDF files that would normally be saved or opened in an external application in a Firefox tab. You can control this feature via a pref on the about:config page.

  • browser.helperApps.showOpenOptionForPdfJS => false
  • pdfjs.handleOctetStream => false
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Thanks for the quick response! Unfortunately, I'm not sure I'm understanding you correctly, so haven't been able to make headway with my issue.

Here's an example pdf which used to happily open in a Firefox tab with the in-browser pdf viewer, and the URL displayed in the address bar (i.e. no download and temp directory): people.stern.nyu.edu/adamodar/pdfiles/val3ed/c05.pdf

It is now impossible for me to open the file in the same way, as I always get prompted for a download, and then the temp dir is shown. Opening the console doesn't seem to be very informative or I'm doing it wrong - on the (empty) tab with the URL of the file, the console is completely empty, while on the new tab with the downloaded pdf (and the temp dir in the address bar), I'm just getting

``` PDF 8a33b47282d8c9c8663c6023c221a863 [1.6 Acrobat Distiller 9.4.0 (Macintosh) / -] (PDF.js: 2.7.69) ```

Again I'm wondering whether anything has changed recently in Firefox? I definitely didn't see this behaviour only a few weeks ago. My workflow includes opening lots of pdfs, and currently it looks like the only way I can keep pdf tabs around while not losing info about the source of the file is to have two tabs for each pdf, one empty tab with just the URL and another tab that actually has the pdf opened from a temp dir. This is really suboptimal and it'd be great to go back to the way it used to work.

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Thanks for the quick response, although I'm not sure I understand you correctly.

Both settings you mention had indeed been `true`, but setting them to `false ` doesn't change behaviour.

Opening the console doesn't seem to give any insights, on the (blank) tab which just shows the original URL in the address bar which stays open after the pdf downloaded and opened in another tab, the console is just empty. On the tab that has the pdf it just shows

PDF 8a33b47282d8c9c8663c6023c221a863 [1.6 Acrobat Distiller 9.4.0 (Macintosh) / -] (PDF.js: 2.7.69)

Here's an example of a pdf which used to open just fine in a FF tab, with URL displayed in the address bar, a few weeks ago, but when I now reload the tab it prompts me for a download and opens a new tab: people.stern.nyu.edu/adamodar/pdfiles/val3ed/c05.pdf

It would be great to be able to get the old behaviour back, as I tend to keep loads of pdfs open during research, and then later on return to reference them as necessary, and currently it seems like I need to keep two tabs open for each pdf if I want to both view the pdf and its URL.

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Works for me.

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

  • switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
  • do NOT click the "Refresh Firefox" button on the Safe Mode start window

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

  • hold down the Shift key and left-click the Reload button
  • press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
  • press "Command + Shift + R" (Mac)

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Remove the Cookies" for websites that cause problems:

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data: "Manage Data"

"Clear the Cache":

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Clear Data -> Cached Web Content: Clear
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Safe mode doesn't change the behaviour, unfortunately. When opening the pdf in the link I posted, I still get the attached window, which offers opening in Firefox or Acrobat. When clicking "Firefox" it downloads the file, and opens a new tab with the file opened from temp dir, and a blank tab with the URL is left next to it.