1947954 - Stop hashing folder names with non-ASCII characters on Windows

Status: RESOLVED FIXED

(MailNews Core :: General, enhancement)

Description

[Geoff Lankow (:darktrojan)]

Since who-knows-when, naming mail files on disk has involved making a hash of the folder's name if it can't be converted from Unicode to "native" encoding and back again. This only affected Windows as everywhere else uses a sensible native encoding. As far as I can tell it hasn't actually been necessary since about 2006, when the code for handling files stopped using native encoding. So we should stop doing it.

This is a backwards-incompatible change in one case: if a new folder is created and then the program is downgraded, older versions won't be able to handle the file name and will start making new files with the hashed name, so it will appear as though the folder's contents are gone. In fact the data will still be there, just unusable by the old version.

Comment 1

[Geoff Lankow (:darktrojan)]

Attachment: Bug 1947954 - Stop hashing folder names with non-ASCII characters on Windows. r=#thunderbird-back-end-reviewers

Depends on D237968.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/62450e0d193b
Stop hashing folder names with non-ASCII characters on Windows. r=mkmelin

Comment 3

[Geoff Lankow (:darktrojan)]

Release Note Request (optional, but appreciated)
[Why is this notable]: This is a backwards-incompatible change. New folders made after this change may disappear if the user downgrades.
[Suggested wording]: File names used when storing mail folders (Windows only).
[Links (documentation, blog post, etc)]: None, but I'll write a bit here for people who find this bug:

---

When you name a mail folder with characters that can't be used to name a file because the operating system won't allow them, Thunderbird creates a different file name. On Windows this also happened to many other characters, because when the code was written using those characters wasn't possible. I've removed that restriction and Thunderbird now behaves the same way on Windows as it does on other operating systems.

If have created a folder using a version of Thunderbird containing this change, then gone back to an older version, your new folder may disappear or appear empty. To work around this:

• Close Thunderbird
• Locate your profile folder and the mail folder in question (inside the Mail or ImapMail folder in your profile) and rename the files to only use the characters A to Z.
• Open Thunderbird. Your folder should be there and contain your mail as before.
• Rename the folder back to the name you want.