templatefilters: add slashpath() to convert path separator to slash

Prepares for deprecating the ui.slash option, which isn't always respected.

mercurial/templatefilters.py

@@ -349,6 +349,11 b' def shortdate(text):'
     """Date. Returns a date like "2006-09-18"."""
     return util.shortdate(text)
 
+@templatefilter('slashpath')
+def slashpath(path):
+    """Any text. Replaces the native path separator with slash."""
+    return util.pconvert(path)
+
 @templatefilter('splitlines')
 def splitlines(text):
     """Any text. Split text into a list of lines."""

tests/test-locate.t

@@ -151,4 +151,13 b' Issue294: hg remove --after dir fails wh'
   $ hg files .
   [1]
 
+Convert native path separator to slash (issue5572)
+
+  $ hg files -T '{path|slashpath}\n'
+  ../b
+  ../dir.h/foo
+  ../t.h
+  ../t/e.h
+  ../t/x
+
   $ cd ../..