View pdf files (file protocol) in firefox

Question

been struggling some time : I want to open a pdf file from *my computer* in firefox : drag and drop produces an address like "file:///C:/path/to/file.pdf" but for clicking enter just pops up the Save dialog and choosing open with firefox just pops the same dialog over and over again
Windows 7 x64, latest FF

Answer 1

In my default profile, renaming mimeTypes.rdf to mimeTypes.old and having Firefox regenerate a default file solves the issue. When I compare the files, there are many, many differences. In addition to "application/pdf" type there is the "application/x-pdf" type, and PDF appears as a possible file extension under everything from plain text files to unknown binary files. I don't think there is a simple way to do an elimination test to figure out what is causing Firefox to display the Open/Save/Cancel dialog. I removed the x-pdf stuff and that didn't work. So I removed every strange reference to PDF and then drag-and-drop worked. Not sure how to describe this bug.
'''Removed the PDF or X-PDF line from these XML elements:'''
<RDF:Seq RDF:about="urn:mimetypes:root">
<RDF:li RDF:resource="urn:mimetype:application/x-pdf"/>
</RDF:Seq>
<RDF:Description RDF:about="urn:mimetype:application/x-octet-stream"
NC:description="Adobe Acrobat 7.0 Document"
NC:value="application/x-octet-stream"
NC:editable="true">
<NC:fileExtensions>pdf</NC:fileExtensions>
<NC:fileExtensions>htm</NC:fileExtensions>
<NC:handlerProp RDF:resource="urn:mimetype:handler:application/x-octet-stream"/>
</RDF:Description>
<RDF:Description RDF:about="urn:mimetype:application/unknow"
NC:description="Adobe Acrobat 7.0 Document"
NC:value="application/unknow"
NC:editable="true">
<NC:fileExtensions>pdf</NC:fileExtensions>
<NC:fileExtensions>htm</NC:fileExtensions>
<NC:handlerProp RDF:resource="urn:mimetype:handler:application/unknow"/>
</RDF:Description>
<RDF:Description RDF:about="urn:mimetype:text/html"
NC:description="Adobe Acrobat 7.0 Document"
NC:value="text/html"
NC:editable="true">
<NC:fileExtensions>pdf</NC:fileExtensions>
<NC:fileExtensions>htm</NC:fileExtensions>
<NC:handlerProp RDF:resource="urn:mimetype:handler:text/html"/>
</RDF:Description>
<RDF:Description RDF:about="urn:mimetype:application/"
NC:value="application/"
NC:editable="true"
NC:description="Adobe Acrobat 7.0 Document">
<NC:fileExtensions>pdf</NC:fileExtensions>
<NC:fileExtensions>htm</NC:fileExtensions>
<NC:handlerProp RDF:resource="urn:mimetype:handler:application/"/>
</RDF:Description>
'''Removed these elements completely:'''
<RDF:Description RDF:about="urn:mimetype:application/x-pdf"
NC:fileExtensions="pdf"
NC:description="Adobe Acrobat 7.0 Document"
NC:value="application/x-pdf"
NC:editable="true">
<NC:handlerProp RDF:resource="urn:mimetype:handler:application/x-pdf"/>
</RDF:Description>
<RDF:Description RDF:about="urn:mimetype:handler:application/x-pdf"
NC:alwaysAsk="true"
NC:saveToDisk="true"
NC:useSystemDefault="false">
<NC:possibleApplication RDF:resource="urn:handler:local:C:\Program Files (x86)\Mozilla Firefox"/>
<NC:possibleApplication RDF:resource="urn:handler:local:C:\Program Files (x86)\Adobe\Reader 10.0\Reader\AcroRd32.exe"/>
<NC:externalApplication RDF:resource="urn:mimetype:externalApplication:application/x-pdf"/>
</RDF:Description>
<RDF:Description RDF:about="urn:mimetype:externalApplication:application/x-pdf"
NC:prettyName="AcroRd32.exe"
NC:path="C:\Program Files (x86)\Adobe\Reader 10.0\Reader\AcroRd32.exe" />
<RDF:Description RDF:about="urn:mimetype:binary/octet-stream"
NC:fileExtensions="pdf"
NC:description="Adobe Acrobat 7.0 Document"
NC:value="binary/octet-stream"
NC:editable="true">
<NC:handlerProp RDF:resource="urn:mimetype:handler:binary/octet-stream"/>
</RDF:Description>
<RDF:Description RDF:about="urn:mimetype:application/download"
NC:fileExtensions="pdf"
NC:description="Adobe Acrobat 7.0 Document"
NC:value="application/download"
NC:editable="true">
<NC:handlerProp RDF:resource="urn:mimetype:handler:application/download"/>
</RDF:Description>