From cf7a9ee63c1167d6e3e3c8c95583df4ab2915a22 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 26 Sep 2016 01:07:05 +0100
Subject: [PATCH] Overwrite: Support --overwrite without a version

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 dgit | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/dgit b/dgit
index 54337f73..5a373630 100755
--- a/dgit
+++ b/dgit
@@ -63,7 +63,7 @@ our $existing_package = 'dpkg';
 our $cleanmode;
 our $changes_since_version;
 our $rmchanges;
-our $overwrite_version;
+our $overwrite_version; # undef: not specified; '': check changelog
 our $quilt_mode;
 our $quilt_modes_re = 'linear|smash|auto|nofix|nocheck|gbp|dpm|unapplied';
 our $we_are_responder;
@@ -2404,8 +2404,26 @@ sub pseudomerge_version_check ($$) {
     my $i_arch_v = [ (getfield $arch_clogp, 'Version'),
 		     'version currently in archive' ];
     if (defined $overwrite_version) {
-	infopair_cond_equal([ $overwrite_version, '--overwrite= version' ],
-			    $i_arch_v);
+	if (length $overwrite_version) {
+	    infopair_cond_equal([ $overwrite_version,
+				  '--overwrite= version' ],
+				$i_arch_v);
+	} else {
+	    my $v = $i_arch_v->[0];
+	    progress "Checking package changelog for archive version $v ...";
+	    eval {
+		my @xa = ("-f$v", "-t$v");
+		my $vclogp = parsechangelog @xa;
+		my $cv = [ (getfield $vclogp, 'Version'),
+			   "Version field from dpkg-parsechangelog @xa" ];
+		infopair_cond_equal($i_arch_v, $cv);
+	    };
+	    if ($@) {
+		$@ =~ s/^dgit: //gm;
+		fail "$@".
+		    "Perhaps debian/changelog does not mention $v ?";
+	    }
+	}
     }
     
     printdebug "pseudomerge_version_check i_arch_v @$i_arch_v\n";
@@ -2423,6 +2441,7 @@ sub pseudomerge_make_commit ($$$$ $$) {
     chomp $msg_msg;
     $msg_cmd .=
 	!defined $overwrite_version ? ""
+	: !length  $overwrite_version ? " --overwrite"
 	: " --overwrite=".$overwrite_version;
 
     mkpath '.git/dgit';
@@ -4564,7 +4583,10 @@ sub parseopts () {
 	    } elsif (m/^--no-rm-on-error$/s) {
 		push @ropts, $_;
 		$rmonerror = 0;
-	    } elsif (m/^--overwrite=(.*)$/s) {
+	    } elsif (m/^--overwrite$/s) {
+		push @ropts, $_;
+		$overwrite_version = '';
+	    } elsif (m/^--overwrite=(.+)$/s) {
 		push @ropts, $_;
 		$overwrite_version = $1;
 	    } elsif (m/^--(no-)?rm-old-changes$/s) {
-- 
2.30.2