[PATCH 6 of 9 debian-packaging] hghave: add a check for debian packaging tools

[Augie Fackler]

# HG changeset patch
# User Augie Fackler <augie at google.com>
# Date 1440475395 14400
#      Tue Aug 25 00:03:15 2015 -0400
# Node ID e3d781ff1bcbcb2f4ad452bc0563d62673545f4c
# Parent  eed9c6f99b2705e627e259722674cf5c2b6d6081
hghave: add a check for debian packaging tools

diff --git a/tests/hghave.py b/tests/hghave.py
--- a/tests/hghave.py
+++ b/tests/hghave.py
@@ -414,6 +414,11 @@ def has_aix():
 def has_osx():
     return sys.platform == 'darwin'
 
+ at check("dpkg", "debian packaging")
+def has_dpkg():
+    return matchoutput('dpkg --version',
+                       "Debian `dpkg' package management program")
+
 @check("absimport", "absolute_import in __future__")
 def has_absimport():
     import __future__