Thunderbird and inline patch attachments

If you're running Thunderbird, depending on how you ever dealt with some types of attachments in the past, there is a chance that, according to how you told Thunderbird to handle some of the types of attachments, you now get an undesirable attachment behaviour.

For instance, if you ever told Thunderbird how it should open a .patch file (eg. with TortoiseGit), you might find that, patches you send are no longer sent as inline text (text/plain), but instead are sent as non-inline (application/force-download). This can be a problem for people reading those patches with dumb e-mail clients, so you might be looking for a way to restore the inline behaviour.

Well, this is usually all handled in the mimeTypes.rdf in your profile. For instance, to get a .patch file to always be sent as inline, you could ensure that you have the following entry:

  <RDF:Description RDF:about="urn:mimetype:text/plain"
                   NC:fileExtensions="patch"
                   NC:description="Patch File"
                   NC:value="text/plain"
                   NC:editable="true">
    <NC:handlerProp RDF:resource="urn:mimetype:handler:text/plain"/>
  </RDF:Description>

In case this isn't enough, another parameter which you want to check is Tools → Advanced → Options → General Tab → Config Editor and then look for mail.content_disposition_type. From what I understand, a value of 0 means that, anything that is not overridden in mimeTypes.rdf will be sent as inline. A value of 1 means that everything is sent as attachment, and a value of 2 means that everything, except images, is sent as attachment, so you probably want to have 0 there.