Add DH_EXTRA_ADDONS env variable to specify local addons.

This is intended to be used by downstreams or specific local configurations
that require a debhelper addon to be run during multiple builds without
having to patch a large number of rules file. If at all possible, this should
be avoided in favor of a --with flag in the rules file.

Signed-off-by: Niels Thykier <niels@thykier.net>

3 files changed, 20 insertions, 1 deletions

diff --git a/debhelper.pod b/debhelper.pod
index dd73c3f9..4cb18257 100644
--- a/debhelper.pod
+++ b/debhelper.pod
@@ -958,6 +958,18 @@ your package is built.
 Multiple things to exclude can be separated with colons, as in
 B<DH_ALWAYS_EXCLUDE=CVS:.svn>
 
+=item B<DH_EXTRA_ADDONS>
+
+If set, this adds the specified dh addons to be run in the appropriate places
+in the sequence of commands. This is equivalent to specifying the addon to run
+with the --with flag in the debian/rules file. Any --without calls specifying
+an addon in this environment variable will not be run.
+
+This is intended to be used by downstreams or specific local configurations
+that require a debhelper addon to be run during multiple builds without
+having to patch a large number of rules file. If at all possible, this should
+be avoided in favor of a --with flag in the rules file.
+
 =back
 
 =head1 SEE ALSO
diff --git a/debian/changelog b/debian/changelog
index e5628893..d49f2716 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,4 +1,10 @@
-debhelper (11.0.1) UNRELEASED; urgency=medium
+debhelper (11.1) UNRELEASED; urgency=medium
+
+  [ Paul Tagliamonte ]
+  * dh: Provide the DH_EXTRA_ADDONS environment as a method for
+    e.g. derivatives to enable additional debhelper add-ons.
+    It is *not* a replacement for the --with parameter (which
+    package maintainers should still use).  (Closes: #570935)
 
   [ Hideki Yamane ]
   * Fix typo of unnecessary.  (Closes: #884574)
diff --git a/dh b/dh
index 3d268268..344d4e93 100755
--- a/dh
+++ b/dh
@@ -303,6 +303,7 @@ if (not compat(9, 1)) {
 	unshift(@ARGV, "--with=build-stamp");
 }
 
+push @{$dh{WITH}},split(",", $ENV{DH_EXTRA_ADDONS});
 
 inhibit_log();