1626523 - Use "\\?\" prefix for UNC path on Windows

Status: NEW

(Core :: XPCOM, enhancement, P3)

Description

[Tom Tung [:tt, :ttung]]

We haven't done this because that would require more work on checking the UNC path.
For instance, \\..., \\UNC\....

Ideally, after prepending, it would look like: \\?\\\UNC\...

See more information in https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maximum-path-length-limitation

"The "\\?\" prefix can also be used with paths constructed according to the universal naming convention (UNC). To specify such a path using UNC, use the "\\?\UNC\" prefix. For example, "\\?\UNC\server\share", where "server" is the name of the computer and "share" is the name of the shared folder."

Comment 1

[Masatoshi Kimura [:emk]]

(In reply to Tom Tung [:tt, :ttung] from comment #0)

"The "\?" prefix

Did markdown unescape \? it should be \\?\.

Comment 2

[Tom Tung [:tt, :ttung]]

(In reply to Masatoshi Kimura [:emk] from comment #1)

(In reply to Tom Tung [:tt, :ttung] from comment #0)

"The "\?" prefix

Did markdown unescape \? it should be \\?\.

Right, \\ was transferred to \. I updated the comment. Thanks!

Comment 3

[Tom Tung [:tt, :ttung]]

This will need to consider IsBlockedUNCPath (Note: there is two checks in the same file)

Comment 4

[Tom Tung [:tt, :ttung]]

Dropping myself from the assignee since I won't work on this in the short term.