Thunderbird picks incorrect mime type for inline picture when drag-and-dropping

[Sparhawk]

When I attach png images by dragging from the file browser to the header region of the compose window, they are attached with correct mimetype.

    Content-Type: image/png;
    name="foo.png"
    Content-Transfer-Encoding: base64
    Content-Disposition: attachment;
    filename="foo.png"

Similarly, *inline* png images attach fine when using Thunderbird's native file picker.

    Content-Type: image/png;
    name="foo.png"
    Content-Transfer-Encoding: base64
    Content-ID: <email address hidden>
    Content-Disposition: inline;
    filename="foo.png"

However, when I attach them inline by *dragging* from the file browser into the body, they are attached with the incorrect mime type as

    Content-Type: text/plain; charset=ISO-8859-1
    Content-Transfer-Encoding: base64
    Content-ID: <email address hidden>

The latter displays fine for the recipient if they are using Thunderbird, or via the gmail web interface. However, OSX Mail.app users only see a text file <Mail Attachment.txt> full of nonsense. Kmail also fails to display the image correctly.

It seems that Thunderbird is using the wrong mime type when png images are attached inline. (I also see a similar problem with .jpg files.)

I see the same problem whether dragging from Dolphin file browser, Konqueror, Krusader, Firefox (via the browser window itself), and Kate's file picker. With Firefox, I entered the file path into the url bar, and dragged from the main browser window. I also attempted to install Nautilus, but I can't even drag from it (with KDE). I've also tried dragging from Firefox's browser window in Xubuntu, which had the same problem.

I tried safe mode, and this didn't fix it. Finally, installing Thunderbird directly from the website *does* fix the problem so it's a problem introduced in the Ubuntu package.

TB 24.1.0
Kubuntu 13.10
KDE 4.11.2

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: thunderbird 1:24.1.0+build1-0ubuntu0.13.10.1
ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3
Uname: Linux 3.11.0-12-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.12.5-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: lee 2253 F.... pulseaudio
BuildID: 20131028125905
CRDA:
 country AU:
  (2402 - 2482 @ 40), (N/A, 20)
  (5170 - 5250 @ 40), (3, 23)
  (5250 - 5330 @ 40), (3, 23), DFS
  (5735 - 5835 @ 40), (3, 30)
Channel: Unavailable
Date: Mon Nov 11 15:18:44 2013
DefaultProfilePrefSources:
 prefs.js
 /usr/lib/mozilla/extensions/{3550f703-e582-4d05-9a08-453d09bdfdc6}/{847b3a00-7ab1-11d4-8f02-006008948af5}/defaults/preferences/enigmail.js
 /usr/lib/mozilla/extensions/{3550f703-e582-4d05-9a08-453d09bdfdc6}/{847b3a00-7ab1-11d4-8f02-006008948af5}/defaults/preferences/000system.js
 [Profile]/extensions/{e2fda1a4-762b-4020-b5ad-a41df1933103}/defaults/preferences/lightning.js
 [Profile]/extensions/{9533f794-00b4-4354-aa15-c2bbda6989f8}/defaults/preferences/prefs.js
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2012-12-16 (329 days ago)
InstallationMedia: Kubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.1)
IpRoute:
 default via 192.168.1.254 dev wlan0 proto static
 192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.4 metric 9
MarkForUpload: True
MostRecentCrashID: bp-8716a067-8317-4ad0-808a-2254e2120524
Profile1PrefSources:
 prefs.js
 /usr/lib/mozilla/extensions/{3550f703-e582-4d05-9a08-453d09bdfdc6}/{847b3a00-7ab1-11d4-8f02-006008948af5}/defaults/preferences/enigmail.js
 /usr/lib/mozilla/extensions/{3550f703-e582-4d05-9a08-453d09bdfdc6}/{847b3a00-7ab1-11d4-8f02-006008948af5}/defaults/preferences/000system.js
Profile1Prefs:
 extensions.lastAppVersion: "24.0" (prefs.js)
 network.cookie.prefsMigrated: true (prefs.js)
Profiles:
 Profile0 (Default) - LastVersion=24.1.0/20131028125905 (In use)
 Profile1 - LastVersion=24.0/20130917155107 (Out of date)
RelatedPackageVersions:
 kopete 4:4.11.2-0ubuntu1
 google-talkplugin 4.7.0.0-1
 rhythmbox-mozilla 2.99.1-0ubuntu1
RunningIncompatibleAddons: False
SourcePackage: thunderbird
SubmittedCrashIDs:
 bp-8716a067-8317-4ad0-808a-2254e2120524
 bp-8c247ae3-5982-4262-b65d-57a252120307
 bp-1ab81b2c-1607-4919-868d-380852120205
UpgradeStatus: Upgraded to saucy on 2013-10-18 (24 days ago)
dmi.bios.date: 09/07/2012
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A19
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 0XN71K
dmi.board.vendor: Dell Inc.
dmi.board.version: FAB1
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: 0.1
dmi.modalias: dmi:bvnDellInc.:bvrA19:bd09/07/2012:svnDellInc.:pnDellSystemXPSL702X:pvr:rvnDellInc.:rn0XN71K:rvrFAB1:cvnDellInc.:ct8:cvr0.1:
dmi.product.name: Dell System XPS L702X
dmi.sys.vendor: Dell Inc.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Gordon Fitch (gcf)]

I experienced the same problem dragging jpgs to message I was composing. The resultant attachment is characterized as something.txt, which confuses many mail readers. It may also be incorrectly encoded. I am running Thunderbird 24.5.0 on Ubuntu 12.4 on a Dell Vostro (32-bit Intel) machine.

[Sparhawk (sparhawkthesecond)]

Gordon, some Apple Mail.app users have told me that they can still see the images if they rename the suffix. I suppose they have to guess what the format is, though.

[Manuel Vazquez Acosta (mva-led)]

With Thunderbird 38.5.1 on Ubuntu 14.04 I see this issue as well.