X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=dgit-badcommit-fixup;h=0a1ebcf61ef208a3b26f36a145ab24cfd53120a7;hp=08b6e3766f2c8c51672a235eda4e339eafbd3c6e;hb=9ceee050983cec221d82053c3e6f6bbbd9ca5f2c;hpb=7e4b51864b864f89089828d9a53b042a7f810177

diff --git a/dgit-badcommit-fixup b/dgit-badcommit-fixup
index 08b6e376..0a1ebcf6 100755
--- a/dgit-badcommit-fixup
+++ b/dgit-badcommit-fixup
@@ -3,15 +3,31 @@
 # Script to help with fallout from #849041.
 #
 # usage:
+#   dgit-badcommit-fixup --check
 #   dgit-badcommit-fixup --test
 #   dgit-badcommit-fixup --real
 
+# Update procedure, from server operator's point of view:
+#
+# 1. Test in an offline tree that this DTRT
+#
+# 2. Announce a transition time.  Tell everyone that between
+#    the transition time and their next upload, they must
+#    run this script.
+#
+# 3. At the transition time, run this script in every repo.
+#
+# 4. Run the mirror script to push changes, if necessary.
+
+
 use strict;
 
 use POSIX;
 use IPC::Open2;
 use Data::Dumper;
 
+our $our_version = 'UNRELEASED'; ###substituted###
+
 my $real;
 
 foreach my $a (@ARGV) {
@@ -19,6 +35,8 @@ foreach my $a (@ARGV) {
 	$real = 0;
     } elsif ($a eq '--real') {
 	$real = 1;
+    } elsif ($a eq '--check') {
+	$real = -1;
     } else {
 	die "$a ?";
     }
@@ -97,13 +115,21 @@ sub rewrite_commit ($) {
     if ($newdata eq $olddata) {
 	$newobj = $obj;
 	$count{unchanged}++;
+#print STDERR "UNCHANGED $obj\n";
     } else {
 	$newobj = hashobj $newdata, 'commit';
+#print STDERR "REWRITTEN $obj $newobj\n";
     }
     $$m= $newobj;
     return $newobj;
 }
 
+our @updates;
+
+sub filter_updates () {
+    @updates = grep { $_->[1] ne $_->[2] } @updates;
+}
+
 sub rewrite_tag ($) {
     my ($obj) = @_;
     $_ = getobj $obj, 'tag';
@@ -123,18 +149,91 @@ sub rewrite_tag ($) {
     return hashobj $_, 'tag';
 }
 
+sub edit_rewrite_map ($) {
+    my ($old) = @_;
+
+    filter_updates();
+    return $old unless @updates;
+
+    my $td = 'dgit-broken-fixup.tmp';
+    runcmd qw(rm -rf), $td;
+    mkdir $td, 0700 or die "$td $!";
+    chdir $td or die $!;
+    runcmd qw(git init -q);
+    runcmd qw(git config gc.auto 0);
+    runcmd qw(rm -rf .git/objects);
+    symlink "../../objects", ".git/objects" or die $!;
+
+    my %map;
+
+    if ($old) {
+	runcmd qw(git checkout -q), $old;
+	open M, "map" or die $!;
+	while (<M>) {
+	    m/^(\w+)(?:\s+(\w+))?$/ or die;
+	    $map{$1} = $2;
+	    $count{rewrite_map_previous}++;
+	}
+	M->error and die $!;
+	close M or die $!;
+    }
+
+    foreach my $oldc (keys %memo) {
+	my $newc = $memo{$oldc};
+	next if $oldc eq $newc;
+	$map{$oldc} = $newc;
+    }
+    foreach my $up (@updates) { # catches tags
+	$map{ $up->[1] } = $up->[2];
+    }
+
+    open M, ">", "map" or die $!;
+    printf M "%s%s\n",
+	$_, (defined $map{$_} ? " $map{$_}" : "")
+	or die $!
+	foreach keys %map;
+    close M or die $!;
+
+    if (!$old) {
+	runcmd qw(git add map);
+    }
+
+    runcmd qw(git commit -q), qw(-m), <<END, qw(map);
+dgit-badcommit-fixup
+
+[dgit-badcommit-fixup $our_version]
+END
+
+    $!=0; $?=0;
+    my $new = `git rev-parse HEAD`;
+    die "$? $!" if $?;
+    chomp $new or die;
+
+    chdir '..' or die $!;
+    runcmd qw(rm -rf), $td;
+
+    $count{rewrite_map_updated}++;
+
+    return $new;
+}
+
 $!=0; $?=0;
 my $refs=`git for-each-ref`;
 die "$? $!" if $?;
 
 chomp $refs;
 
-our @updates;
+our $org_rewrite_map;
 
 foreach my $rline (split /\n/, $refs) {
     my ($obj, $type, $refname) = 
 	$rline =~ m/^(\w+)\s+(\w+)\s+(\S.*)/
 	or die "$_ ?";
+    if ($refname eq 'refs/dgit-rewrite/map') {
+	$org_rewrite_map = $obj;
+	next;
+    }
+    next if $refname =~ m{^refs/dgit-(?:badcommit|badfixuptest)/};
     my $rewrite;
     if ($type eq 'commit') {
 	$rewrite = rewrite_commit($obj);
@@ -144,45 +243,62 @@ foreach my $rline (split /\n/, $refs) {
 	warn "ref $refname refers to $type\n";
 	next;
     }
-    next if $rewrite eq $obj;
     push @updates, [ $refname, $obj, $rewrite ];
 }
 
-our $worktree;
-
-#print Dumper(\@updates);
+if ($bare eq 'true') {
+    my $new_rewrite_map = edit_rewrite_map($org_rewrite_map);
+    push @updates, [ 'refs/dgit-rewrite/map',
+		     ($org_rewrite_map // '0'x40),
+		     ($new_rewrite_map // '0'x40),
+		     1 ];
+}
 
-open U, "|git update-ref -m 'dgit bad commit fixup' --stdin" or die $!;
+filter_updates();
 
-if ($real && $bare eq 'false') {
-    print "detaching your HEAD\n" or die $!;
-    runcmd 'git checkout --detach';
+if (!@updates) {
+    print Dumper(\%count), "all is well - nothing to do\n";
+    exit 0;
 }
 
+#print Dumper(\@updates);
+
+open U, "|git update-ref -m 'dgit bad commit fixup' --stdin" or die $!
+    if $real >= 0;
+
 for my $up (@updates) {
-    my ($ref, $old, $new) = @$up;
+    my ($ref, $old, $new, $nobackup) = @$up;
     my $otherref = $ref;
     $otherref =~ s{^refs/}{};
-    if ($real) {
-	print U <<END or die $!;
+    if ($real > 0) {
+	print U <<END or die $! unless $nobackup;
 create refs/dgit-badcommit/$otherref $old
+END
+	print U <<END or die $!;
 update $ref $new $old
 END
-    } else {
+    } elsif ($real==0) {
 	print U <<END or die $!;
 update refs/dgit-badfixuptest/$otherref $new
 END
+    } else {
+	print "found trouble in history of $ref\n" or die $!;
     }
 }
 
-$?=0; $!=0;
-close U or die "$? $!";
-die $? if $?;
+if ($real >= 0) {
+    $?=0; $!=0;
+    close U or die "$? $!";
+    die $? if $?;
+}
 
 print Dumper(\%count);
 
-if ($real) {
+if ($real >= 0) {
     print "old values saved in refs/dgit-badcommit/\n" or die $!;
-} else {
+} elsif ($real == 0) {
     print "testing output saved in refs/dgit-badfixuptest/\n" or die $!;
+} else {
+    print STDERR "found work to do, exiting status 2\n";
+    exit 2;
 }