Your bug report

#4823: w32 paths `substitute-in-file-name' fails when environmental variable  is set for \\ style paths:

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 4823@debbugs.gnu.org.

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4823: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=4823
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