dh_clean: Work around for cdbs d/compat auto-vivification

cdbs has a feature where it will create debian/compat and set its
contents to 5 if it does not exist (and DH_COMPAT does not exist).

The issue being builds generally call "clean" before "build" and as
such packages relying on this feature now FTBFS.  As they were not
listed as packages in danger (lintian considered them to have compat 5
or greater), we now instate this work around to cater for them.

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

2 files changed, 18 insertions, 0 deletions

diff --git a/debian/changelog b/debian/changelog
index 9d36bb73..e95487c4 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,5 +1,12 @@
 debhelper (9.20151117) UNRELEASED; urgency=medium
 
+  [ Niels Thykier ]
+  * dh_clean: Temporarily interpret the absence of d/compat and
+    DH_COMPAT to mean compat 5.  This is to avoid breaking
+    packages that rely on cdbs to set debian/compat to 5 during
+    the build.  This temporary work around will live until
+    d/compat becomes mandatory.  (Closes: #805404)
+
   [ Translations ]
   * Update German translation (Chris Leick)
     (Closes: #802198)
diff --git a/dh_clean b/dh_clean
index 042d8ef9..38dc04af 100755
--- a/dh_clean
+++ b/dh_clean
@@ -72,6 +72,17 @@ slash.  Any content in these directories will be removed as well.
 
 =cut
 
+if ( not -f 'debian/compat' and not $ENV{'DH_COMPAT'}) {
+	# Temporary work around - Permit a missing compat to work with
+	# cdbs's feature of auto-creating a d/compat file.
+	#  - Auto-bump to compat 5 to match cdbs (Not that it matters a lot,
+	#    since there is no compat conditions for 4 or less)
+	warning("Pretending DH_COMPAT was set to 5");
+	warning(" - this is a temporary measure to avoid FTBFS in packages");
+	warning("   relying on cdbs to set debian/compat to 5 during the build");
+	$ENV{'DH_COMPAT'} = 5;
+}
+
 init(options => {
 	"dirs-only" => \$dh{D_FLAG},
 });