Review for InlineDisposition by RobertJ
Rated 2 out of 5 stars
Works sometimes. I have a financial site that uses Content-Disposition = attachment for pdf files. It also uses Content-Type = Application/pdf.
Even with this add-on, for this site FF asks me to save the pdf and does not display it in FF.
Note: that in Preferences > Applications "Display in Firefox" is selected.
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