scripts/mk: Add support for an improved dpkg_vendor_derives_from macro

Version the macros so that both can be used, and default the unversioned
one to the version 0 macro.

7 files changed, 52 insertions, 8 deletions

diff --git a/debian/changelog b/debian/changelog
index 4a4446434..aa84c615e 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -23,6 +23,9 @@ dpkg (1.19.3) UNRELEASED; urgency=medium
     Reported by Andreas Beckmann <anbe@debian.org>. Closes: #916799
   * vendor.mk: Fix dpkg_vendor_derives_from macro documentation.
     Thanks to Colin Watson <cjwatson@debian.org>. Closes: #913816
+  * vendor.mk: Add support for an improved dpkg_vendor_derives_from macro.
+    Version the macros so that both can be used, and default the unversioned
+    one to the version 0 macro.
   * Perl modules:
     - Dpkg::Changelog::Debian: Preserve modelines at EOF. Closes: #916056
       Thanks to Chris Lamb <lamby@debian.org> for initial test cases.
diff --git a/scripts/Makefile.am b/scripts/Makefile.am
index aacd630fc..ea8aef557 100644
--- a/scripts/Makefile.am
+++ b/scripts/Makefile.am
@@ -364,6 +364,8 @@ test_data = \
 	t/mk/buildflags.mk \
 	t/mk/buildtools.mk \
 	t/mk/pkg-info.mk \
+	t/mk/vendor-v0.mk \
+	t/mk/vendor-v1.mk \
 	t/mk/vendor.mk \
 	t/origins/debian \
 	t/origins/default \
diff --git a/scripts/mk/vendor.mk b/scripts/mk/vendor.mk
index fe06828f5..f3b1565bb 100644
--- a/scripts/mk/vendor.mk
+++ b/scripts/mk/vendor.mk
@@ -3,16 +3,40 @@
 # DEB_VENDOR: output of dpkg-vendor --query Vendor
 # DEB_PARENT_VENDOR: output of dpkg-vendor --query Parent (can be empty)
 #
-# The snippet also defines a macro "dpkg_vendor_derives_from" that you can
-# use to verify if the current vendor derives from another vendor with a
-# simple test like this one:
-# ifeq ($(shell $(call dpkg_vendor_derives_from,ubuntu)),yes)
-#   ...
-# endif
+# This Makefile snippet also defines a set "dpkg_vendor_derives_from"
+# macros that can be used to verify if the current vendor derives from
+# another vendor. The unversioned variant defaults to the v0 version if
+# undefined, which can be defined explicitly to one of the versions or the
+# versioned macros can be used directly. The following are example usages:
+#
+# - dpkg_vendor_derives_from (since dpkg 1.16.1)
+#
+#   ifeq ($(shell $(call dpkg_vendor_derives_from,ubuntu)),yes)
+#     ...
+#   endif
+#
+# - dpkg_vendor_derives_from_v0 (since dpkg 1.19.3)
+#
+#   ifeq ($(shell $(call dpkg_vendor_derives_from_v0,ubuntu)),yes)
+#     ...
+#   endif
+#
+# - dpkg_vendor_derives_from_v1 (since dpkg 1.19.3)
+#
+#   dpkg_vendor_derives_from = $(dpkg_vendor_derives_from_v1)
+#   ifeq ($(call dpkg_vendor_derives_from,ubuntu),yes)
+#     ...
+#   endif
+#   ifeq ($(call dpkg_vendor_derives_from_v1,ubuntu),yes)
+#     ...
+#   endif
 
 dpkg_late_eval ?= $(or $(value DPKG_CACHE_$(1)),$(eval DPKG_CACHE_$(1) := $(shell $(2)))$(value DPKG_CACHE_$(1)))
 
 DEB_VENDOR = $(call dpkg_late_eval,DEB_VENDOR,dpkg-vendor --query Vendor)
 DEB_PARENT_VENDOR = $(call dpkg_late_eval,DEB_PARENT_VENDOR,dpkg-vendor --query Parent)
 
-dpkg_vendor_derives_from = dpkg-vendor --derives-from $(1) && echo yes || echo no
+dpkg_vendor_derives_from_v0 = dpkg-vendor --derives-from $(1) && echo yes || echo no
+dpkg_vendor_derives_from_v1 = $(shell $(dpkg_vendor_derives_from_v0))
+
+dpkg_vendor_derives_from ?= $(dpkg_vendor_derives_from_v0)
diff --git a/scripts/t/mk.t b/scripts/t/mk.t
index 0062e993c..98c7e5083 100644
--- a/scripts/t/mk.t
+++ b/scripts/t/mk.t
@@ -16,7 +16,7 @@
 use strict;
 use warnings;
 
-use Test::More tests => 6;
+use Test::More tests => 8;
 use Test::Dpkg qw(:paths);
 
 use File::Spec::Functions qw(rel2abs);
@@ -117,5 +117,7 @@ foreach my $tool (keys %buildtools) {
 test_makefile('pkg-info.mk');
 
 test_makefile('vendor.mk');
+test_makefile('vendor-v0.mk');
+test_makefile('vendor-v1.mk');
 
 1;
diff --git a/scripts/t/mk/vendor-v0.mk b/scripts/t/mk/vendor-v0.mk
new file mode 100644
index 000000000..602a8c63a
--- /dev/null
+++ b/scripts/t/mk/vendor-v0.mk
@@ -0,0 +1,6 @@
+dpkg_vendor_derives_from = $(dpkg_vendor_derives_from_v0)
+
+include $(srcdir)/mk/vendor.mk
+
+test:
+	test "$(shell $(call dpkg_vendor_derives_from,debian))" = "yes"
diff --git a/scripts/t/mk/vendor-v1.mk b/scripts/t/mk/vendor-v1.mk
new file mode 100644
index 000000000..11c1314ef
--- /dev/null
+++ b/scripts/t/mk/vendor-v1.mk
@@ -0,0 +1,6 @@
+include $(srcdir)/mk/vendor.mk
+
+dpkg_vendor_derives_from = $(dpkg_vendor_derives_from_v1)
+
+test:
+	test "$(call dpkg_vendor_derives_from,debian)" = "yes"
diff --git a/scripts/t/mk/vendor.mk b/scripts/t/mk/vendor.mk
index 371b39c87..4e0d9ff89 100644
--- a/scripts/t/mk/vendor.mk
+++ b/scripts/t/mk/vendor.mk
@@ -3,3 +3,4 @@ include $(srcdir)/mk/vendor.mk
 test:
 	test "$(DEB_VENDOR)" = "Debian"
 	test "$(DEB_PARENT_VENDOR)" = ""
+	test "$(shell $(call dpkg_vendor_derives_from,debian))" = "yes"