254169 - URLs do not convert "%5C" to "\"

Status: RESOLVED WONTFIX

(Core :: Networking, defect)

Description

[andy]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040616
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040616

When you enter this URL in IE:
file:///C:%5CProgram%20Files%5CMacromedia%5CFlash%20MX%5CUntitled-1.html

You get this:
C:\Program Files\Macromedia\Flash MX\Untitled-1.html

Mozilla does not convert this type of URL, and subsequently, does not browse to
the correct location. 

Reproducible: Always
Steps to Reproduce:
1. Point IE to "file:///c:%5C". Notice it converts "%5C" to "\"
2. Point Mozilla to "file:///c:%5C". Mozilla does not convert the URL.

Actual Results:  
The page could not be found

Expected Results:  
Mozilla converts "file:///c:%5C" to "file:///c:\"

When you publish a preview in flash MX, flash puts these "%5C" into the URL
which causes the preview only to work in Internet Exploiter. If Mozilla also
parses the URL, then there will be one less reason to keep IE around.

Comment 1

[Frank Wein [:mcsmurf]]

file:///c:%5C shows the drive C: for me, so does file:///c:\ so everything is
correct. And there is no need to convert something in file:///c:%5C, since the \
needs to be escaped and that was already done here (\ is a so-called unsafe
character). Tested with current CVS trunk build on win2k.

Comment 2

[Christian :Biesinger (don't email me, ping me on IRC)]

the problem is of course that the base uri will be wrong, so relative links in
the page won't work

Comment 3

[Darin Fisher]

The patch in bug 249282 makes '\' work in Mozilla on Win32 and OS/2, but I don't
think it will solve this problem.

Comment 4

[OstGote!]

As comment 1 it WFM. file:///c:%5c shows "Index of file:///c:\" as page and the
URL remains file:///c:%5c which is correct behavior. So the page can be found.

(In reply to comment #2)
> the problem is of course that the base uri will be wrong, so relative links in
> the page won't work

Could you explain this on an example? I guess you mean something like in Bug
236440 because "\" is not treated as a path separator for URLs.

Comment 5

[Christian :Biesinger (don't email me, ping me on IRC)]

(In reply to comment #4)
> Could you explain this on an example? I guess you mean something like in Bug
> 236440 because "\" is not treated as a path separator for URLs.

yes.

Comment 6

[Joel Peterson]

Confirmed on Firefox PR1. \ in links are treated directly at %5C, instead of /.
This breaks files with URLs containing the unfortunate \ instead of /. If there
aren't any other compatibility issues as a result, it would be best to treat /
and \ the same.

Comment 7

[cafebabe1991]

Is there a patch available to convert \ to / in mozilla firefox.If yes can i get the steps to install it.?

Comment 8

[Patrick McManus [:mcmanus]]

valentin, what do you think the status of this bug should be?

Comment 9

[Valentin Gosu [:valentin] (he/him)]

Tehnically, it still applies, but I think we should WONTFIX it.
comment 0 is a bit confusing but it seems the problem is that 
file:///C:/Program%20Files%5CTest/../ is resolved to file:///C:/ instead of file:///C:/Program%20Files

The parser does translate regular \ to /. When opening the file for the given file URI, it unescapes the path, so we get the correct folder but %5C doesn't get replaced with /.
We could do it, but I wouldn't encourage this kind of special casing.

I have to note that Chrome has the same behaviour as Firefox (while edge and IE open a window to that path, so I can't really check). 
So does this URL parser implementation: http://intertwingly.net/projects/pegurl/liveview3.html

The URL spec doesn't indicate that we should convert %5C to \ when parsing the URL, so I think WONTFIX would be appropriate.