test-pager: make it compatible with chg

chg's runpager implementation is different. It behaves differently for the
"shell=False, command not found" case.

Differential Revision: https://phab.mercurial-scm.org/D911

tests/test-pager.t

@@ -195,6 +195,7 b' even though stdout is no longer a tty.'
   paged! 'summary:     modify a 8\n'
   paged! '\n'
 
+#if no-chg
 An invalid pager command name is reported sensibly if we don't have to
 use shell=True in the subprocess call:
   $ hg log --limit 3 --config pager.pager=this-command-better-never-exist
@@ -215,6 +216,17 b' use shell=True in the subprocess call:'
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     modify a 8
   
+#else
+Currently, chg has its own runpager implementation, which does not show the
+"missing pager" message. The error message is globed out since the shell could
+print different message.
+  $ hg log --limit 3 --config pager.pager=this-command-better-never-exist
+  /bin/sh: this-command-better-never-exist: command not found (?)
+  * (glob) (?)
+  killed!
+  [255]
+
+#endif
 
 A complicated pager command gets worse behavior. Bonus points if you can
 improve this.