http://bugs.winehq.org/show_bug.cgi?id=34730
--- Comment #14 from oiaohm oiaohm@gmail.com --- Bit more testing it is a problem I created under dosdevices unc\test\test\test.exe
wine cmd /c '//test/test/test.exe' wine cmd /c '\test\test\test.exe'
Guess what both should work. Go back to versions of wine where direct running Linux commands work. Only 1 of those lines work.
Both of those lines are valid under Windows. So prior versions of wine were in fact Windows application incompadbile.
So what ever fix is done cannot break UNC.
The current patch breaks UNC.