X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=git-debrebase;h=d3ed731ba97e299fe2a8c9368799abc7d5691480;hb=11f20779c3a2d56ebdf9430737b7960bd628b16d;hp=563fb9970fa4f7bb8f7ac46c4d7b583e8d68f36a;hpb=3411945b1ae36797de420b0e6e5bcf75e1e28c7f;p=dgit.git

diff --git a/git-debrebase b/git-debrebase
index 563fb997..d3ed731b 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -55,6 +55,8 @@ our ($opt_defaultcmd_interactive);
 
 our $us = qw(git-debrebase);
 
+our $wrecknoteprefix = 'refs/debrebase-wreckage';
+
 $|=1;
 
 sub badusage ($) {
@@ -152,6 +154,14 @@ our $snags_summarised = 0;
 our @deferred_updates;
 our @deferred_update_messages;
 
+sub merge_wreckage_cleaning ($) {
+    my ($updates) = @_;
+    git_for_each_ref("$wrecknoteprefix/*", sub {
+	my ($objid,$objtype,$fullrefname,$reftail) = @_;
+	push @$updates, "delete $fullrefname";
+    });
+}
+
 sub all_snags_summarised () {
     $snags_forced + $snags_tripped == $snags_summarised;
 }
@@ -160,6 +170,7 @@ sub run_deferred_updates ($) {
 
     confess 'dangerous internal error' unless all_snags_summarised();
 
+    merge_wreckage_cleaning \@deferred_updates;
     run_ref_updates_now $mrest, \@deferred_updates;
     print $_, "\n" foreach @deferred_update_messages;
 
@@ -368,9 +379,35 @@ sub gbp_pq_export ($$$) {
 #  our own patch identification algorithm?
 #  this is an alternative strategy
 
+sub merge_failed ($$) {
+    my ($wrecknotes, $emsg) = @_;
+    my @m;
+    push @m, "Merge resolution failed: $emsg";
+
+    changedir $maindir;
+
+    my @updates;
+    merge_wreckage_cleaning \@updates;
+    keys %$wrecknotes;
+    while (my ($k,$v) = each %$wrecknotes) {
+	push @updates, "create $wrecknoteprefix/$k $v";
+    }
+    run_ref_updates_now "merge failed", \@updates;
+    push @m, "Wreckage left in $wrecknoteprefix/*.";
+
+    push @m, "See git-debrebase(1) section FAILED MERGES for suggestions.";
+
+    # use finish rather than fail, in case we are within an eval
+    # (that can happen inside walk!)
+    print STDERR "\n";
+    print STDERR "$us: $_\n" foreach @m;
+    finish 15;
+}
+
 sub mwrecknote ($$$) {
     my ($wrecknotes, $reftail, $commitish) = @_;
     confess unless defined $commitish;
+    printdebug "mwrecknote $reftail $commitish\n";
     $wrecknotes->{$reftail} = $commitish;
 }
 
@@ -402,6 +439,15 @@ sub merge_series ($$$;@) {
 
     my $mwrecknote = sub { &mwrecknote($wrecknotes, @_); };
 
+    my $attempt_cmd = sub {
+	debugcmd '+', @_;
+	$!=0; $?=-1;
+	if (system @_) {
+	    failedcmd_report_cmd undef, @_;
+	    merge_failed $wrecknotes, failedcmd_waitstatus();
+	}
+    };
+
     local $workarea = fresh_playground "$playprefix/merge";
     my $seriesfile = "debian/patches/series";
     in_workarea sub {
@@ -461,11 +507,8 @@ sub merge_series ($$$;@) {
 	runcmd @git, qw(checkout -q -b merge);
 	printdebug "merge_series merging...\n";
 	my @mergecmd = (@git, qw(merge --quiet --no-edit), "p-1");
-	debugcmd '+', @mergecmd;
-	$!=0; $?=-1;
-	if (system @mergecmd) {
-	    failedcmd @mergecmd;
-	}
+
+	$attempt_cmd->(@mergecmd);
 
 	printdebug "merge_series merge ok, series...\n";
 	# We need to construct a new series file
@@ -541,7 +584,8 @@ sub merge_series ($$$;@) {
 	$mwrecknote->('merged-patchqueue', git_rev_parse 'HEAD');
 
 	printdebug "merge_series series gbp pq import\n";
-	runcmd qw(gbp pq import);
+
+	$attempt_cmd->(qw(gbp pq import));
 
 	# OK now we are on patch-queue/merge, and we need to rebase
 	# onto the intended parent and drop the patches from each one
@@ -1045,7 +1089,8 @@ sub walk ($;$$$) {
     };
 
     my $nomerge = sub {
-	fail "something useful about failed merge attempt @_ xxx".Dumper($cl);
+	my ($emsg) = @_;
+	merge_failed $cl->{MergeWreckNotes}, $emsg;
     };
 
     my $mwrecknote = sub { &mwrecknote($cl->{MergeWreckNotes}, @_); };
@@ -1299,8 +1344,9 @@ sub walk ($;$$$) {
 	    my ($btip, $bbw, $banchor) = eval {
 		walk $ib, 0, $report, $report_lprefix.'  ';
 	    };
-	    $nomerge->("walking interchange branch merge base ($ibleaf): ".
-		       $@) if length $@;
+	    $nomerge->("walking interchange branch merge base ($ibleaf):\n".
+		       $@)
+		if length $@;
 
 	    $mwrecknote->("mergebase-laundered", $btip);
 	    $mwrecknote->("mergebase-breakwater", $bbw);