User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/20100101 Firefox/19.0 Build ID: 20130215130331 Steps to reproduce: I tested the new integrated PDF-Viewer in v19 under Win7/64/Prof with a standard URI of a PDF-Report in a Web-Application. It worked well, as long I did not select the checkbox "Für Dateien dieses Typs immer diese Aktion ausführen" in the attached screenshot (see Part 1 in BUG_Firefox_v19_PDF-Viewer.pdf). Actual results: When I selected this checkbox, i Firefox_v19 created new Tabs in a endless loop until I closed whole Window. See attached screenshot (see Part 2 in BUG_Firefox_v19_PDF-Viewer.pdf). Expected results: Firefox should present only one new Tab inlcuding the selected PDF-Report.

See http://support.mozilla.org/en-US/kb/firefox-repeatedly-opens-empty-tabs-or-windows

I open pdf Mozilla 19 and opened new tab and exit! (flash in screen for tab)

Klaus, is the issue still reproducible in latest Firefox versions? Thank you

Marking as RWFM, please reopen the issue if it is still reproducible on latest builds, after checking the link from Comment 1.

Same problem here. [Manjaro 0.8.9 - Firefox 28.0 Beta 6] When I have assigned Firefox as predetermined pdf viewer and I have opened a pdf file a endless loop of tabs has appeared Build: 20140224220227 [testday-20140227]

Re-open based on comment 5, thanks Yunito!

I cannot reproduce this bug using Windows XP and Firefox 28 Beta 6, build: Mozilla/5.0 (Windows NT 5.1; rv:28.0) Gecko/20100101 Firefox/28.0

Resolving since comment 5 is for Linux and per discussion at http://irclog.gr/#show/irc.mozilla.org/testday/45721 . The steps below has no relation to the PDF viewer and indicate bad software configuration: 1. Open Edit->Preferences-Applications 2. Set "Web Feed" to "use other..." then "/usr/bin/firefox" 3. Open "http://www.npr.org/rss/rss.php?id=1001"

I have the same issue with the newest version on Windows 7: Go to the URL: http://www.ligne-roset.com/Content/Resources/en-GB/pdf/General_Guide_for_Upholsery.pdf This causes that Firefox keeps opening hundreds of empty tabs with the URL: C:/Users/thh/AppData/Local/Temp/General_Guide_for_Upholsery-1.pdf Please do not mark this bug as RESOLVED! It is anything but.

ThomasH, please to configure PDF Document to use "Preview in Firefox" in the Preferences->Applications. Otherwise your configuration is invalid and not a subject to this bug.