Issue #6470: Drop UNC prefix in FixTk.py
Patch by Christop Gohlke and Amaury Forgeot d'Arc.
diff --git a/Lib/lib-tk/FixTk.py b/Lib/lib-tk/FixTk.py
index 0d0966c..49960c7 100644
--- a/Lib/lib-tk/FixTk.py
+++ b/Lib/lib-tk/FixTk.py
@@ -42,6 +42,8 @@
         # Ignore leading \\?\
         if s.startswith("\\\\?\\"):
             s = s[4:]
+        if s.startswith("UNC"):
+            s = "\\" + s[3:]
         return s
 
 prefix = os.path.join(sys.prefix,"tcl")