templater: replace templatepath() with function that also opens the file For frozen binaries, such as those created by PyOxidizer, I plan to make it so the templatespec can keep an opened file/resource to read from instead of needing a file path. Having `templatepath()` return an opened file should help with that. At this point, it's just a wasteful extra opening of mapfiles that we'll open again later. I'll update the read-side next so it reads from the file-like object without opening the file again. Differential Revision: https://phab.mercurial-scm.org/D8892

--- a/mercurial/formatter.py	Thu Jul 30 13:44:06 2020 -0700
+++ b/mercurial/formatter.py	Tue Aug 04 13:21:29 2020 -0700
@@ -599,9 +599,9 @@
 
     # perhaps a stock style?
     if not os.path.split(tmpl)[0]:
-        mapname = templater.templatepath(
+        (mapname, fp) = templater.open_template(
             b'map-cmdline.' + tmpl
-        ) or templater.templatepath(tmpl)
+        ) or templater.open_template(tmpl)
         if mapname:
             return mapfile_templatespec(topic, mapname)