1670356 - [Windows] Duplicate lowercase extension appended to executable downloads with uppercase extension

Status: VERIFIED FIXED

(Firefox :: File Handling, defect, P2)

Description

[Samuel Leslie]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0

Steps to reproduce:

Downloading files with an uppercase extension (e.g. "EXE") results in a duplicate lowercase extension being appended to the download (e.g. "exe"). For example, if a user downloads "PROGRAM.EXE", Firefox will save it as "PROGRAM.EXE.exe".

This is a regression which appears to have been introduced in Firefox 81.0.

A sample URL to try:
https://download.microsoft.com/download/8/1/9/819227B2-B066-41CC-9EF9-5426F0F0F886/IE11_BlockerToolkit.EXE

Actual results:

Download has a duplicate lowercase extension appended.

Expected results:

File extension is preserved as-is by default.

Comment 1

[Alice0775 White]

I can reproduce the issue on Nightly83.0a1 Windows10.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=5860b7b7c7a435fc09b05af7f19242662cdc7a1c&tochange=840272088ab1ee282b937ee38d9dc9f95b4d54b1

Comment 2

[:Gijs (he/him)]

Sigh.

Comment 4

[:Gijs (he/him)]

This is Windows-specific, and the culprit is https://searchfox.org/mozilla-central/rev/40b561b9accbff54387edcba2b8b4a3c3828110e/toolkit/mozapps/downloads/HelperAppDlg.jsm#469,479 ; I missed this despite explicitly checking for a case like this when fixing bug 1655457 because the code is both specific to Windows and to executables (and, as the other bug was about PDFs, I probably tested with pdfs)...

Comment 5

[:Gijs (he/him)]

Attachment: Bug 1670356 - use case insensitive comparisons when checking Windows executables, r?mak

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/81801ba1e2cf
use case insensitive comparisons when checking Windows executables, r=mak

Comment 7

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/81801ba1e2cf

Comment 8

[:Gijs (he/him)]

Comment on attachment 9182125 [details]
Bug 1670356 - use case insensitive comparisons when checking Windows executables, r?mak

Beta/Release Uplift Approval Request

• User impact if declined: Broken behaviour for windows users downloading executables with shouty extensions
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): one-line change + automated tests, super early in beta.
• String changes made/needed: no

Comment 9

[Pascal Chevrel (relman team) -> :pascalc]

Comment on attachment 9182125 [details]
Bug 1670356 - use case insensitive comparisons when checking Windows executables, r?mak

Looks safe, approved for 83 beta 3, thanks.

Comment 10

[Julien Cristau [:jcristau]]

https://hg.mozilla.org/releases/mozilla-beta/rev/897c7f6bcc4e

Comment 11

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Reproduced the issue with Firefox 83.0a1 (20201009214545) on Windows 10x64.
The issue is verified fixed with Firefox 84.0a1 (20201022215159) and Firefox 83.0b3 (20201022171613) on Windows 10x64.