diff mercurial/chgserver.py @ 31954:e518192d6bac

pager: set some environment variables if they're not set

Git did this already [1] [2]. We want this behavior too [3].

This provides a better default user experience (like, supporting colors) if
users have things like "PAGER=less" set, which is not uncommon.

The environment variables are provided by a method so extensions can
override them on demand.

[1]: https://github.com/git/git/blob/6a5ff7acb5965718cc7016c0ab6c601454fd7cde/pager.c#L87
[2]: https://github.com/git/git/blob/6a5ff7acb5965718cc7016c0ab6c601454fd7cde/Makefile#L1545
[3]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/094780.html

--- a/mercurial/chgserver.py	Thu Apr 13 14:48:18 2017 -0400
+++ b/mercurial/chgserver.py	Thu Apr 13 08:27:19 2017 -0700
@@ -190,8 +190,8 @@
             self.flush()
             return self._csystem(cmd, util.shellenviron(environ), cwd)
 
-        def _runpager(self, cmd):
-            self._csystem(cmd, util.shellenviron(), type='pager',
+        def _runpager(self, cmd, env=None):
+            self._csystem(cmd, util.shellenviron(env), type='pager',
                           cmdtable={'attachio': attachio})
             return True