From 6e24ac7bb85e30df00b3d14853b049e3f06b6dec Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 25 Oct 2013 10:23:30 +0100
Subject: dgit build, by default, uses the archive to find out what the correct
 -v<version> option is to pass to dpkg-genchanges.

---
 debian/changelog |  2 ++
 dgit             | 31 ++++++++++++++++++++++++++++---
 dgit.1           | 17 ++++++++++++++++-
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index 3ecbbdb..7acc8ed 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,5 +1,7 @@
 dgit (0.17~experimental4) experimental; urgency=low
 
+  * dgit build, by default, uses the archive to find out what the correct
+    -v<version> option is to pass to dpkg-genchanges.
   * When using sbuild, pass the arguments to mergechanges in the right
     order so that we use the correct Description (the _source one,
     not the one from sbuild which didn't get e.g. -v<version>).
diff --git a/dgit b/dgit
index 441114d..254e3fb 100755
--- a/dgit
+++ b/dgit
@@ -45,6 +45,7 @@ our $ignoredirty = 0;
 our $noquilt = 0;
 our $existing_package = 'dpkg';
 our $cleanmode = 'dpkg-source';
+our $changes_since_version;
 our $we_are_responder;
 our $initiator_tempdir;
 
@@ -113,8 +114,6 @@ sub dscfn ($) {
     return "${package}_".(stripepoch $vsn).".dsc";
 }
 
-sub changesopts () { return @changesopts[1..$#changesopts]; }
-
 our $us = 'dgit';
 our $debugprefix = '';
 
@@ -1690,6 +1689,26 @@ sub build_prep () {
     build_maybe_quilt_fixup();
 }
 
+sub changesopts () {
+    my @opts =@changesopts[1..$#changesopts];
+    if (!defined $changes_since_version) {
+	my @vsns = archive_query('archive_query');
+	if (@vsns) {
+	    @vsns = map { $_->[0] } @vsns;
+	    @vsns = sort { version_compare_string($a, $b) } @vsns;
+	    $changes_since_version = $vsns[0];
+	    progress "changelog will contain changes since $vsns[0]";
+	} else {
+	    $changes_since_version = '_';
+	    progress "package seems new, not specifying -v<version>";
+	}
+    }
+    if ($changes_since_version ne '_') {
+	unshift @opts, "-v$changes_since_version";
+    }
+    return @opts;
+}
+
 sub cmd_build {
     badusage "dgit build implies --clean=dpkg-source"
 	if $cleanmode ne 'dpkg-source';
@@ -1818,6 +1837,9 @@ sub parseopts () {
 	    } elsif (m/^--new$/) {
 		push @ropts, $_;
 		$new_package=1;
+	    } elsif (m/^--since-version=([^_]+|_)$/) {
+		push @ropts, $_;
+		$changes_since_version = $1;
 	    } elsif (m/^--(\w+)=(.*)/s &&
 		     ($om = $opts_opt_map{$1}) &&
 		     length $om->[0]) {
@@ -1871,7 +1893,10 @@ sub parseopts () {
 		} elsif (s/^-N/-/) {
 		    push @ropts, $&;
 		    $new_package=1;
-		} elsif (m/^-[vm]/) {
+		} elsif (s/^-v([^_]+|_)$//s) {
+		    push @ropts, $&;
+		    $changes_since_version = $1;
+		} elsif (m/^-m/) {
 		    push @ropts, $&;
 		    push @changesopts, $_;
 		    $_ = '';
diff --git a/dgit.1 b/dgit.1
index 931b831..c261300 100644
--- a/dgit.1
+++ b/dgit.1
@@ -248,7 +248,22 @@ more output (currently, up to -DD is meaningfully different).
 Specifies a git configuration option.  dgit itself is also controlled
 by git configuration options.
 .TP
-.RI \fB-v\fR version |\fB-m\fR maintaineraddress
+.RI \fB-v\fR version "|\fB_\fR | " \fB--since-version=\fR version |\fB_\fR
+Specifies the
+.BI -v version
+option to pass to dpkg-genchanges, during builds.  Changes (from
+debian/changelog) since this version will be included in the built
+changes file, and hence in the upload.  If this option is not
+specified, dgit will query the archive and use the latest version
+uploaded to the intended suite.
+
+Specifying
+.B _
+inhibits this, so that no -v option will be passed to dpkg-genchanges
+(and as a result, only the last stanza from debian/changelog will
+be used for the build and upload).
+.TP
+.RI \fB-m\fR maintaineraddress
 Passed to dpkg-genchanges (eventually).
 .TP
 .RI \fB--ch:\fR option
-- 
cgit v1.2.3