1679071 - "Open with" should not add .txt for files served with text/plain mimetype if there is header/<a download> information about the filename including an extension

Status: NEW

(Firefox :: File Handling, defect, P5)

Description

[tustamido]

Tested with a fresh new profile using Firefox 84 on Windows 10.

Firefox should respect suggested file extension even if MIME type is text/plain.

Example:

• Install Imagus addon.
• Go to its Options, click Sieve then click export button (↑).
• Download popup will show up. It's a JSON file, but without proper MIME type.
• If you click to save, it's all right, file will be saved as .json (Imagus-sieve.json).
• But if you use "Open with", Firefox will save it in %TEMP% folder as .txt (more precisely: Imagus-sieve.json-1.txt).

I have also experienced this in Skype Web while trying to open PDF file misstyped as text/plain. Firefox adds .txt and of course the file doesn't open correctly.

My workaround was to manually edit handlers.json adding
"text/plain":{"action":4,"ask":true,"extensions":["json","pdf",...],...
but Firefox should handle this by default.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:Gijs, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 2

[:Gijs (he/him)]

Is this a regression? When did it break?

Comment 3

[tustamido]

(In reply to :Gijs (he/him) from comment #2)

Is this a regression? When did it break?

I don't think so, it's reproducible even with Fx 56.

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:Gijs, could you have a look please?

For more information, please visit auto_nag documentation.