X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=git-debrebase;h=2a2d1ed2c81e0a83f987ccdeb8e2c6d2d426254b;hp=60ea976116fa1afad615a8c8be17e2171b55d7bf;hb=c10954df2a6f7ed9f12e12f6e65049d78c9672e4;hpb=5f0580a8bbf6460363d208acfab53714f190a7a6

diff --git a/git-debrebase b/git-debrebase
index 60ea9761..2a2d1ed2 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -395,8 +395,8 @@ sub merge_series ($$;@) {
 	foreach my $q ($base_q, reverse @input_qs) {
 	    my $s = $q->{MR}{S};
 	    gbp_pq_export "p-$s", $q->{SeriesBase}, $q->{SeriesTip};
+	    my @earlier;
 	    if (open S, $seriesfile) {
-		my @earlier;
 		while (my $patch = <S>) {
 		    chomp $patch or die $!;
 		    $prereq{$patch} //= {};
@@ -424,6 +424,20 @@ sub merge_series ($$;@) {
                 "[git-debrebase merge-innards patch-queue prep:".
                 " $q->{SeriesTip}]"
             ];
+
+	    read_tree_debian $newbase;
+	    if (@earlier) {
+		read_tree_subdir 'debian/patches', "$pec:debian/patches";
+	    } else {
+		rm_subdir_cached 'debian/patches';
+	    }
+	    $pec = make_commit [ $pec ], [
+ "Update debian/ (excluding patches) to final to avoid re-merging",
+ "debian/ was already merged and we need to just take that.",
+                "[git-debrebase merge-innards patch-queue packaging:".
+                " $q->{SeriesTip}]"
+            ];
+
 	    printdebug "pec' $pec\n";
             runcmd @git, qw(reset -q --hard), $pec;
 	    $q->{MR}{PEC} = $pec;
@@ -832,6 +846,8 @@ sub mergedbreakwaters_anchor ($) {
 	$best_anchor = $panchor
 	    if !defined $best_anchor
 	    or is_fast_fwd $best_anchor, $panchor;
+	fail "inconsistent anchors in merged-breakwaters $p->{CommitId}"
+	    unless is_fast_fwd $panchor, $best_anchor;
     }
     return $best_anchor;
 }
@@ -1013,6 +1029,11 @@ sub walk ($;$$$) {
 	fail "something useful about failed merge attempt @_ xxx".Dumper($cl);
     };
 
+    my $mwrecknote = sub {
+	my ($reftail, $commitish) = @_;
+	$cl->{MergeWreckNotes}{$reftail} = $commitish;
+    };
+
     my $last_anchor;
 
     for (;;) {
@@ -1116,7 +1137,11 @@ sub walk ($;$$$) {
 		return $bomb->();
 	    }
 	    die "$ty ?";
-	} elsif ($ty eq 'VanillaMerge' or $ty eq 'MergedBreakwaters') {
+	} elsif ($ty eq 'MergedBreakwaters') {
+	    $last_anchor = mergedbreakwaters_anchor $cl;
+	    $build_start->(' MergedBreakwaters', $cur);
+	    last;
+	} elsif ($ty eq 'VanillaMerge') {
 	    # User may have merged unstitched branch(es).  We will
 	    # have now lost what ffq-prev was then (since the later
 	    # pseudomerge may introduce further changes).  The effect
@@ -1152,15 +1177,14 @@ sub walk ($;$$$) {
 
 	    printdebug "*** MERGE\n";
 
-	    # xxx avoid calling walk without nogenerate when
-	    # we have a MergedBreakwater; instead call keycommits ?
-
 	    my @bwbcmd = (@git, qw(merge-base));
 	    my @ibcmd = (@git, qw(merge-base --all));
 	    my $might_be_in_bw = 1;
 
 	    my $ps = $cl->{Parents};
 
+	    $mwrecknote->('vanilla-merge', $cl->{CommitId});
+
 	    foreach my $p (@$ps) {
 		$prline->(" VanillaMerge ".$p->{Ix});
 		$prprdelim->();
@@ -1171,6 +1195,17 @@ sub walk ($;$$$) {
 		$p->{Breakwater} = $p->{SeriesBase} = $pbw;
 		$p->{Anchor} = $panchor;
 
+		my $lr = $p->{LeftRight} = (qw(left right))[$p->{Ix}];
+		$mwrecknote->("$lr-input", $p->{CommitId});
+
+		my $mwrecknote_parent = sub {
+		    my ($which) = @_;
+		    $mwrecknote->("$lr-".(lc $which), $p->{$which});
+		};
+		$mwrecknote_parent->('Laundered');
+		$mwrecknote_parent->('Breakwater');
+		$mwrecknote_parent->('Anchor');
+
 		$best_anchor = $panchor if
 		    !defined $best_anchor or
 		    is_fast_fwd $best_anchor, $panchor;
@@ -1179,10 +1214,12 @@ sub walk ($;$$$) {
 		    " p=$panchor\n";
 	    }
 
+	    $mwrecknote->('result-anchor', $best_anchor);
+
 	    foreach my $p (@$ps) {
 		$prline->(" VanillaMerge ".$p->{Ix});
 		if (!is_fast_fwd $p->{Anchor}, $best_anchor) {
-		    $nomerge->('DivergentAnchor');
+		    $nomerge->('divergent anchors');
 		} elsif ($p->{Anchor} eq $best_anchor) {
 		    print $report " SameAnchor" if $report;
 		} else {
@@ -1200,14 +1237,14 @@ sub walk ($;$$$) {
 	    }
 
 	    if ($ok && $might_be_in_bw) {
+		# We could rewrite this to contaion the metadata
+		# declaring it to be MergedBreakwaters, but
+		# unnecessarily rewriting a merge seems unhelpful.
 		$prline->(" VanillaMerge MergedBreakwaters");
 		$last_anchor = $best_anchor;
 		$build_start->('MergedBreakwaters', $cur);
 	    }
 
-	    $nomerge->("alleged merged-breakwater is not a breakwater")
-		unless $ty eq 'VanillaMerge';
-
 	    my $bwb = cmdoutput @bwbcmd;
 
 	    # OK, now we have a breakwater base, but we need the merge
@@ -1218,17 +1255,39 @@ sub walk ($;$$$) {
 	    # breakwater merge base as an ancestor.
 
 	    my @ibs =
-		grep { is_fast_fwd $bwb, $_ }
 		grep /./,
 		split /\n/,
 		cmdoutput @ibcmd;
-	    my ($ib) = @ibs
-		or $nomerge->("no suitable interchange merge base");
+
+            @ibs or confess 'internal error, expected anchor at least ?';
+
+	    my $ib;
+	    my $ibleaf;
+	    foreach my $tibix (0..$#ibs) {
+		my $tib = $ibs[$tibix];
+		my $ff = is_fast_fwd $bwb, $tib;
+		my $ok = !$ff ? 'rej' : $ib ? 'extra' : 'ok';
+		my $tibleaf = "interchange-mbcand-$ok-$tibix";
+		$mwrecknote->($tibleaf, $tib);
+		next unless $ff;
+		next if $ib;
+		$ib = $tib;
+		$ibleaf = $tibleaf;
+	    }
+
+	    $ib or $nomerge->("no suitable interchange merge base");
 
 	    $prline->("  VanillaMerge Base");
 	    $prprdelim->();
-	    my ($btip, $bbw, $banchor) =
+	    my ($btip, $bbw, $banchor) = eval {
 		walk $ib, 0, $report, $report_lprefix.'  ';
+	    };
+	    $nomerge->("walking interchange branch merge base ($ibleaf): ".
+		       $@) if length $@;
+
+	    $mwrecknote->("mergebase-laundered", $btip);
+	    $mwrecknote->("mergebase-breakwater", $bbw);
+	    $mwrecknote->("mergebase-anchor", $banchor);
 
 	    my $ibinfo = { SeriesTip => $btip,
 			   SeriesBase => $bbw,
@@ -1237,6 +1296,7 @@ sub walk ($;$$$) {
 		or $nomerge->("interchange merge-base ($ib)'s".
 			      " breakwater ($bbw)".
 			      " != breakwaters' merge-base ($bwb)");
+
 	    grep { $_->{Anchor} eq $ibinfo->{Anchor} } @$ps
 		 or $nomerge->("interchange merge-base ($ib)'s".
 			       " anchor ($ibinfo->{SeriesBase})".
@@ -1244,7 +1304,6 @@ sub walk ($;$$$) {
 			       (join ' ', map { $_->{Anchor} } @$ps).
 			       ")");
 
-
 	    $cl->{MergeInterchangeBaseInfo} = $ibinfo;
 	    $cl->{MergeBestAnchor} = $best_anchor;
 	    push @brw_cl, {
@@ -1276,6 +1335,11 @@ sub walk ($;$$$) {
 
     my $rewriting = 0;
 
+    my $read_tree_upstream = sub {
+	my ($treeish) = @_;
+	read_tree_upstream $treeish, 0, $build;
+    };
+
     $#upp_cl = $upp_limit if defined $upp_limit;
  
     my $committer_authline = calculate_committer_authline();
@@ -1303,7 +1367,7 @@ sub walk ($;$$$) {
 	    if ($method eq 'Debian') {
 		read_tree_debian($cltree);
 	    } elsif ($method eq 'Upstream') {
-		read_tree_upstream($cltree);
+		$read_tree_upstream->($cltree);
 	    } elsif ($method eq 'StartRewrite') {
 		$rewriting = 1;
 		next;
@@ -1316,13 +1380,13 @@ sub walk ($;$$$) {
  		confess unless $rewriting;
 		my $differs = (get_differs $build, $cltree);
 		next unless $differs & D_UPS;
-		read_tree_upstream($cltree);
+		$read_tree_upstream->($cltree);
 		push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
 	    } elsif ($method eq 'MergeCreateMergedBreakwaters') {
 		print "Found a general merge, will try to tidy it up.\n";
 		$rewriting = 1;
-		read_tree_upstream($cl->{MergeBestAnchor});
-		read_tree_upstream($cl->{MergeBestAnchor});
+		$read_tree_upstream->($cl->{MergeBestAnchor});
+		$read_tree_upstream->($cl->{MergeBestAnchor});
 		read_tree_debian($cltree);
 		@parents = map { $_->{Breakwater} } @{ $cl->{Parents} };
 	    } elsif ($method eq 'MergeMergeSeries') {