Cannot upload GIF image files as GIF in Media Gallery or Questions

[mirunacurtean]

Affected platforms:
Windows 10 64-bit
Android 8
macOS 14.10.6

Browser version:
FF 77
Chrome 83.1
Safari

Environment:
Production
Stage
Dev

Precondition:
Create account and sign in.

Steps to reproduce:

1. Go to Contributor Tools> Media gallery and select to Upload a New Media File.
2. Browse a GIF file and select it.

Expected results:
A second 'Upload a New Media file' modal should show up containing fields such as Locale, Tile and Description info to fill in before uploading.

Actual Results:
No second modal shows up and file remains selected even if modal is closed until page is refreshed.

Note: This does not occur when uploading a smaller sized image (PNG, JPEG) #1026

[mirunacurtean]

Updating issue after re-test.

[AliceWyman]

I also see this problem now when I try to upload a PNG file to the Media Gallery. I tried a JPG file and that still works.

[AliceWyman]

I filed https://bugzilla.mozilla.org/show_bug.cgi?id=1751620 on the PNG issue.

[mirunacurtean]

Updating this with new repro steps:

1. From https://support.allizom.org/en-US/gallery/images select Upload a New Media File
2. Select browse and navigate the local folders to the image folders.
3. Select a GIF image under 10 MB.
4. Finish uploading it and look at the

Results:
Like in the bugzilla ticket comment 1 regarding JPEG, the GIF is submitted as a PNG.

Example:
https://support.allizom.org/en-US/gallery/images