git-debrebase: merge: Call merge_failed in merge_series

[dgit.git] / git-debrebase

diff --git a/git-debrebase b/git-debrebase
index 277e0f843aac6641172abccc48beaefd781cb5f4..464a14c4bb03bab5a0c7c8b7adc944e3387a555c 100755 (executable)
--- 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 ($) {
@@ -131,12 +133,35 @@ sub fresh_workarea () {
     in_workarea sub { playtree_setup };
 }
 
+sub run_ref_updates_now ($$) {
+    my ($mrest, $updates) = @_;
+    # @$updates is a list of lines for git-update-ref, without \ns
+
+    my @upd_cmd = (git_update_ref_cmd "debrebase: $mrest", qw(--stdin));
+    debugcmd '>|', @upd_cmd;
+    open U, "|-", @upd_cmd or die $!;
+    foreach (@$updates) {
+       printdebug ">= ", $_, "\n";
+       print U $_, "\n" or die $!;
+    }
+    printdebug ">\$\n";
+    close U or failedcmd @upd_cmd;
+}
+
 our $snags_forced = 0;
 our $snags_tripped = 0;
 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 == $snags_summarised;
 }
@@ -145,16 +170,8 @@ sub run_deferred_updates ($) {
 
     confess 'dangerous internal error' unless all_snags_summarised();
 
-    my @upd_cmd = (git_update_ref_cmd "debrebase: $mrest", qw(--stdin));
-    debugcmd '>|', @upd_cmd;
-    open U, "|-", @upd_cmd or die $!;
-    foreach (@deferred_updates) {
-       printdebug ">= ", $_, "\n";
-       print U $_, "\n" or die $!;
-    }
-    printdebug ">\$\n";
-    close U or failedcmd @upd_cmd;
-
+    merge_wreckage_cleaning \@deferred_updates;
+    run_ref_updates_now $mrest, \@deferred_updates;
     print $_, "\n" foreach @deferred_update_messages;
 
     @deferred_updates = ();
@@ -362,8 +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;
 }
 
@@ -395,6 +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 {
@@ -448,17 +501,14 @@ sub merge_series ($$$;@) {
            printdebug "pec' $pec\n";
             runcmd @git, qw(reset -q --hard), $pec;
            $q->{MR}{PEC} = $pec;
-           $mwrecknote->("$q->{LeftRight}-patchqueue");
+           $mwrecknote->("$q->{LeftRight}-patchqueue", $pec);
        }
        # now, because of reverse, we are on $input_q->{MR}{OQC}
        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
@@ -534,7 +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
@@ -1038,7 +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}, @_); };
@@ -1047,6 +1099,7 @@ sub walk ($;$$$) {
 
     for (;;) {
        $cl = classify $cur;
+       $cl->{MergeWreckNotes} //= {};
        my $ty = $cl->{Type};
        my $st = $cl->{SubType};
        $prline->("$cl->{CommitId} $cl->{Type}");