From a75a91f40d31452a0c02761540416e5957f91d35 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 30 Jan 2018 18:30:44 +0000
Subject: [PATCH] git-debrebase: walk: return last upstream merge in breakwater
 branch

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 git-debrebase | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/git-debrebase b/git-debrebase
index 1961bcc5..8a431110 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -473,7 +473,7 @@ sub walk ($;$$);
 sub walk ($;$$) {
     my ($input,
 	$nogenerate,$report) = @_;
-    # => ($tip, $breakwater_tip)
+    # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
     # (or nothing, if $nogenerate)
 
     # go through commits backwards
@@ -529,6 +529,8 @@ sub walk ($;$$) {
 	no warnings qw(exiting); last;
     };
 
+    my $last_upstream_update;
+
     for (;;) {
 	$cl = classify $cur;
 	my $ty = $cl->{Type};
@@ -546,6 +548,7 @@ sub walk ($;$$) {
 	    $cur = $p0;
 	    next;
 	} elsif ($ty eq 'BreakwaterStart') {
+            $last_upstream_update = $cur;
 	    $build_start->('FirstPackaging', $cur);
 	} elsif ($ty eq 'Upstream') {
 	    push @upp_cl, $cl;
@@ -570,6 +573,7 @@ sub walk ($;$$) {
 	    $cur = $contrib;
 	    next;
 	} elsif ($ty eq 'BreakwaterUpstreamMerge') {
+            $last_upstream_update = $cur;
 	    $build_start->("PreviousBreakwater", $cur);
 	} elsif ($ty eq 'DgitImportUnpatched') {
 	    my $pm = $pseudomerges[-1];
@@ -729,6 +733,9 @@ sub walk ($;$$) {
 	    my $newcommit = cmdoutput @cmd;
 	    confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
 	    $build = $newcommit;
+            if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
+                $last_upstream_update = $cur;
+            }
 	}
     };
 
@@ -736,7 +743,7 @@ sub walk ($;$$) {
     die sprintf "internal error %#x %s %s", $final_check, $build, $input
 	if $final_check & ~D_PAT_ADD;
 
-    return ($build, $breakwater);
+    return ($build, $breakwater, $last_upstream_update);
 }
 
 sub get_head () { return git_rev_parse qw(HEAD); }
-- 
2.30.2