dffd134e63b2f37fb59631d2884afaa13a7625d3
[git.git] / git-cvsimport-script
1 #!/usr/bin/perl -w
2
3 # This tool is copyright (c) 2005, Matthias Urlichs.
4 # It is released under the Gnu Public License, version 2.
5 #
6 # The basic idea is to aggregate CVS check-ins into related changes.
7 # Fortunately, "cvsps" does that for us; all we have to do is to parse
8 # its output.
9 #
10 # Checking out the files is done by a single long-running CVS connection
11 # / server process.
12 #
13 # The head revision is on branch "origin" by default.
14 # You can change that with the '-o' option.
15
16 use strict;
17 use warnings;
18 use Getopt::Std;
19 use File::Path qw(mkpath);
20 use File::Basename qw(basename dirname);
21 use Time::Local;
22 use IO::Socket;
23 use IO::Pipe;
24 use POSIX qw(strftime dup2);
25
26 $SIG{'PIPE'}="IGNORE";
27 $ENV{'TZ'}="UTC";
28
29 our($opt_h,$opt_o,$opt_v,$opt_d,$opt_p,$opt_C);
30
31 sub usage() {
32         print STDERR <<END;
33 Usage: ${\basename $0}     # fetch/update GIT from CVS
34            [ -o branch-for-HEAD ] [ -h ] [ -v ] [ -d CVSROOT ]
35        [ -p opts-for-cvsps ] [ -C GIT_repository ]
36        [ CVS_module ]
37 END
38         exit(1);
39 }
40
41 getopts("hqvo:d:p:C:") or usage();
42 usage if $opt_h;
43
44 @ARGV <= 1 or usage();
45
46 if($opt_d) {
47         $ENV{"CVSROOT"} = $opt_d;
48 } elsif(-f 'CVS/Root') {
49         open my $f, '<', 'CVS/Root' or die 'Failed to open CVS/Root';
50         $opt_d = <$f>;
51         chomp $opt_d;
52         close $f;
53         $ENV{"CVSROOT"} = $opt_d;
54 } elsif($ENV{"CVSROOT"}) {
55         $opt_d = $ENV{"CVSROOT"};
56 } else {
57         die "CVSROOT needs to be set";
58 }
59 $opt_o ||= "origin";
60 my $git_tree = $opt_C;
61 $git_tree ||= ".";
62
63 my $cvs_tree;
64 if ($#ARGV == 0) {
65         $cvs_tree = $ARGV[0];
66 } elsif (-f 'CVS/Repository') {
67         open my $f, '<', 'CVS/Repository' or 
68             die 'Failed to open CVS/Repository';
69         $cvs_tree = <$f>;
70         chomp $cvs_tree;
71         close $f
72 } else {
73         usage();
74 }
75
76 select(STDERR); $|=1; select(STDOUT);
77
78
79 package CVSconn;
80 # Basic CVS dialog.
81 # We're only interested in connecting and downloading, so ...
82
83 use POSIX qw(strftime dup2);
84
85 sub new {
86         my($what,$repo,$subdir) = @_;
87         $what=ref($what) if ref($what);
88
89         my $self = {};
90         $self->{'buffer'} = "";
91         bless($self,$what);
92
93         $repo =~ s#/+$##;
94         $self->{'fullrep'} = $repo;
95         $self->conn();
96
97         $self->{'subdir'} = $subdir;
98         $self->{'lines'} = undef;
99
100         return $self;
101 }
102
103 sub conn {
104         my $self = shift;
105         my $repo = $self->{'fullrep'};
106         if($repo =~ s/^:pserver:(?:(.*?)(?::(.*?))?@)?([^:\/]*)(?::(\d*))?//) {
107                 my($user,$pass,$serv,$port) = ($1,$2,$3,$4);
108                 $user="anonymous" unless defined $user;
109                 my $rr2 = "-";
110                 unless($port) {
111                         $rr2 = ":pserver:$user\@$serv:$repo";
112                         $port=2401;
113                 }
114                 my $rr = ":pserver:$user\@$serv:$port$repo";
115
116                 unless($pass) {
117                         open(H,$ENV{'HOME'}."/.cvspass") and do {
118                                 # :pserver:cvs@mea.tmt.tele.fi:/cvsroot/zmailer Ah<Z
119                                 while(<H>) {
120                                         chomp;
121                                         s/^\/\d+\s+//;
122                                         my ($w,$p) = split(/\s/,$_,2);
123                                         if($w eq $rr or $w eq $rr2) {
124                                                 $pass = $p;
125                                                 last;
126                                         }
127                                 }
128                         };
129                 }
130                 $pass="A" unless $pass;
131
132                 my $s = IO::Socket::INET->new(PeerHost => $serv, PeerPort => $port);
133                 die "Socket to $serv: $!\n" unless defined $s;
134                 $s->write("BEGIN AUTH REQUEST\n$repo\n$user\n$pass\nEND AUTH REQUEST\n")
135                         or die "Write to $serv: $!\n";
136                 $s->flush();
137
138                 my $rep = <$s>;
139
140                 if($rep ne "I LOVE YOU\n") {
141                         $rep="<unknown>" unless $rep;
142                         die "AuthReply: $rep\n";
143                 }
144                 $self->{'socketo'} = $s;
145                 $self->{'socketi'} = $s;
146         } else { # local: Fork off our own cvs server.
147                 my $pr = IO::Pipe->new();
148                 my $pw = IO::Pipe->new();
149                 my $pid = fork();
150                 die "Fork: $!\n" unless defined $pid;
151                 unless($pid) {
152                         $pr->writer();
153                         $pw->reader();
154                         dup2($pw->fileno(),0);
155                         dup2($pr->fileno(),1);
156                         $pr->close();
157                         $pw->close();
158                         exec("cvs","server");
159                 }
160                 $pw->writer();
161                 $pr->reader();
162                 $self->{'socketo'} = $pw;
163                 $self->{'socketi'} = $pr;
164         }
165         $self->{'socketo'}->write("Root $repo\n");
166
167         # Trial and error says that this probably is the minimum set
168         $self->{'socketo'}->write("Valid-responses ok error Valid-requests Mode M Mbinary E F Checked-in Created Updated Merged Removed\n");
169
170         $self->{'socketo'}->write("valid-requests\n");
171         $self->{'socketo'}->flush();
172
173         chomp(my $rep=$self->readline());
174         if($rep !~ s/^Valid-requests\s*//) {
175                 $rep="<unknown>" unless $rep;
176                 die "Expected Valid-requests from server, but got: $rep\n";
177         }
178         chomp(my $res=$self->readline());
179         die "validReply: $res\n" if $res ne "ok";
180
181         $self->{'socketo'}->write("UseUnchanged\n") if $rep =~ /\bUseUnchanged\b/;
182         $self->{'repo'} = $repo;
183 }
184
185 sub readline {
186         my($self) = @_;
187         return $self->{'socketi'}->getline();
188 }
189
190 sub _file {
191         # Request a file with a given revision.
192         # Trial and error says this is a good way to do it. :-/
193         my($self,$fn,$rev) = @_;
194         $self->{'socketo'}->write("Argument -N\n") or return undef;
195         $self->{'socketo'}->write("Argument -P\n") or return undef;
196         # $self->{'socketo'}->write("Argument -ko\n") or return undef;
197         # -ko: Linus' version doesn't use it
198         $self->{'socketo'}->write("Argument -r\n") or return undef;
199         $self->{'socketo'}->write("Argument $rev\n") or return undef;
200         $self->{'socketo'}->write("Argument --\n") or return undef;
201         $self->{'socketo'}->write("Argument $self->{'subdir'}/$fn\n") or return undef;
202         $self->{'socketo'}->write("Directory .\n") or return undef;
203         $self->{'socketo'}->write("$self->{'repo'}\n") or return undef;
204         # $self->{'socketo'}->write("Sticky T1.0\n") or return undef;
205         $self->{'socketo'}->write("co\n") or return undef;
206         $self->{'socketo'}->flush() or return undef;
207         $self->{'lines'} = 0;
208         return 1;
209 }
210 sub _line {
211         # Read a line from the server.
212         # ... except that 'line' may be an entire file. ;-)
213         my($self) = @_;
214         die "Not in lines" unless defined $self->{'lines'};
215
216         my $line;
217         my $res="";
218         while(defined($line = $self->readline())) {
219                 # M U gnupg-cvs-rep/AUTHORS
220                 # Updated gnupg-cvs-rep/
221                 # /daten/src/rsync/gnupg-cvs-rep/AUTHORS
222                 # /AUTHORS/1.1///T1.1
223                 # u=rw,g=rw,o=rw
224                 # 0
225                 # ok
226
227                 if($line =~ s/^(?:Created|Updated) //) {
228                         $line = $self->readline(); # path
229                         $line = $self->readline(); # Entries line
230                         my $mode = $self->readline(); chomp $mode;
231                         $self->{'mode'} = $mode;
232                         defined (my $cnt = $self->readline())
233                                 or die "EOF from server after 'Changed'\n";
234                         chomp $cnt;
235                         die "Duh: Filesize $cnt" if $cnt !~ /^\d+$/;
236                         $line="";
237                         $res="";
238                         while($cnt) {
239                                 my $buf;
240                                 my $num = $self->{'socketi'}->read($buf,$cnt);
241                                 die "Server: Filesize $cnt: $num: $!\n" if not defined $num or $num<=0;
242                                 $res .= $buf;
243                                 $cnt -= $num;
244                         }
245                 } elsif($line =~ s/^ //) {
246                         $res .= $line;
247                 } elsif($line =~ /^M\b/) {
248                         # output, do nothing
249                 } elsif($line =~ /^Mbinary\b/) {
250                         my $cnt;
251                         die "EOF from server after 'Mbinary'" unless defined ($cnt = $self->readline());
252                         chomp $cnt;
253                         die "Duh: Mbinary $cnt" if $cnt !~ /^\d+$/ or $cnt<1;
254                         $line="";
255                         while($cnt) {
256                                 my $buf;
257                                 my $num = $self->{'socketi'}->read($buf,$cnt);
258                                 die "S: Mbinary $cnt: $num: $!\n" if not defined $num or $num<=0;
259                                 $res .= $buf;
260                                 $cnt -= $num;
261                         }
262                 } else {
263                         chomp $line;
264                         if($line eq "ok") {
265                                 # print STDERR "S: ok (".length($res).")\n";
266                                 return $res;
267                         } elsif($line =~ s/^E //) {
268                                 # print STDERR "S: $line\n";
269                         } else {
270                                 die "Unknown: $line\n";
271                         }
272                 }
273         }
274 }
275 sub file {
276         my($self,$fn,$rev) = @_;
277         my $res;
278
279         if ($self->_file($fn,$rev)) {
280                 $res = $self->_line();
281                 return $res if defined $res;
282         }
283
284         # retry
285         $self->conn();
286         $self->_file($fn,$rev)
287                 or die "No file command send\n";
288         $res = $self->_line();
289         die "No input: $fn $rev\n" unless defined $res;
290         return $res;
291 }
292
293
294 package main;
295
296 my $cvs = CVSconn->new($opt_d, $cvs_tree);
297
298
299 sub pdate($) {
300         my($d) = @_;
301         m#(\d{2,4})/(\d\d)/(\d\d)\s(\d\d):(\d\d)(?::(\d\d))?#
302                 or die "Unparseable date: $d\n";
303         my $y=$1; $y-=1900 if $y>1900;
304         return timegm($6||0,$5,$4,$3,$2-1,$y);
305 }
306
307 sub pmode($) {
308         my($mode) = @_;
309         my $m = 0;
310         my $mm = 0;
311         my $um = 0;
312         for my $x(split(//,$mode)) {
313                 if($x eq ",") {
314                         $m |= $mm&$um;
315                         $mm = 0;
316                         $um = 0;
317                 } elsif($x eq "u") { $um |= 0700;
318                 } elsif($x eq "g") { $um |= 0070;
319                 } elsif($x eq "o") { $um |= 0007;
320                 } elsif($x eq "r") { $mm |= 0444;
321                 } elsif($x eq "w") { $mm |= 0222;
322                 } elsif($x eq "x") { $mm |= 0111;
323                 } elsif($x eq "=") { # do nothing
324                 } else { die "Unknown mode: $mode\n";
325                 }
326         }
327         $m |= $mm&$um;
328         return $m;
329 }
330
331 my $tmpcv = "/var/cache/cvs";
332
333 sub getwd() {
334         my $pwd = `pwd`;
335         chomp $pwd;
336         return $pwd;
337 }
338
339 -d $git_tree
340         or mkdir($git_tree,0777)
341         or die "Could not create $git_tree: $!";
342 chdir($git_tree);
343
344 my $last_branch = "";
345 my $orig_branch = "";
346 my %branch_date;
347
348 my $git_dir = $ENV{"GIT_DIR"} || ".git";
349 $git_dir = getwd()."/".$git_dir unless $git_dir =~ m#^/#;
350 $ENV{"GIT_DIR"} = $git_dir;
351 unless(-d $git_dir) {
352         system("git-init-db");
353         die "Cannot init the GIT db at $git_tree: $?\n" if $?;
354         system("git-read-tree");
355         die "Cannot init an empty tree: $?\n" if $?;
356
357         $last_branch = $opt_o;
358         $orig_branch = "";
359 } else {
360         -f "$git_dir/refs/head/$opt_o"
361                 or die "Branch '$opt_o' does not exist.\n".
362                        "Either use the correct '-o branch' option,\n".
363                        "or import to a new repository.\n";
364
365         $last_branch = basename(readlink("$git_dir/HEAD"));
366         unless($last_branch) {
367                 warn "Cannot read the last branch name: $! -- assuming 'master'\n";
368                 $last_branch = "master";
369         }
370         $orig_branch = $last_branch;
371
372         # Get the last import timestamps
373         opendir(D,"$git_dir/refs/heads");
374         while(defined(my $head = readdir(D))) {
375                 next if $head =~ /^\./;
376                 open(F,"$git_dir/refs/heads/$head")
377                         or die "Bad head branch: $head: $!\n";
378                 chomp(my $ftag = <F>);
379                 close(F);
380                 open(F,"git-cat-file commit $ftag |");
381                 while(<F>) {
382                         next unless /^author\s.*\s(\d+)\s[-+]\d{4}$/;
383                         $branch_date{$head} = $1;
384                         last;
385                 }
386                 close(F);
387         }
388         closedir(D);
389 }
390
391 -d $git_dir
392         or die "Could not create git subdir ($git_dir).\n";
393
394 my $pid = open(CVS,"-|");
395 die "Cannot fork: $!\n" unless defined $pid;
396 unless($pid) {
397         my @opt;
398         @opt = split(/,/,$opt_p) if defined $opt_p;
399         exec("cvsps",@opt,"-x","-A","--cvs-direct",'--root',$opt_d,$cvs_tree);
400         die "Could not start cvsps: $!\n";
401 }
402
403
404 ## cvsps output:
405 #---------------------
406 #PatchSet 314
407 #Date: 1999/09/18 13:03:59
408 #Author: wkoch
409 #Branch: STABLE-BRANCH-1-0
410 #Ancestor branch: HEAD
411 #Tag: (none)
412 #Log:
413 #    See ChangeLog: Sat Sep 18 13:03:28 CEST 1999  Werner Koch
414 #Members:
415 #       README:1.57->1.57.2.1
416 #       VERSION:1.96->1.96.2.1
417 #
418 #---------------------
419
420 my $state = 0;
421
422 my($patchset,$date,$author,$branch,$ancestor,$tag,$logmsg);
423 my(@old,@new);
424 my $commit = sub {
425         my $pid;
426         while(@old) {
427                 my @o2;
428                 if(@old > 55) {
429                         @o2 = splice(@old,0,50);
430                 } else {
431                         @o2 = @old;
432                         @old = ();
433                 }
434                 system("git-update-cache","--force-remove","--",@o2);
435                 die "Cannot remove files: $?\n" if $?;
436         }
437         while(@new) {
438                 my @n2;
439                 if(@new > 55) {
440                         @n2 = splice(@new,0,50);
441                 } else {
442                         @n2 = @new;
443                         @new = ();
444                 }
445                 system("git-update-cache","--add","--",@n2);
446                 die "Cannot add files: $?\n" if $?;
447         }
448
449         $pid = open(C,"-|");
450         die "Cannot fork: $!" unless defined $pid;
451         unless($pid) {
452                 exec("git-write-tree");
453                 die "Cannot exec git-write-tree: $!\n";
454         }
455         chomp(my $tree = <C>);
456         length($tree) == 40
457                 or die "Cannot get tree id ($tree): $!\n";
458         close(C)
459                 or die "Error running git-write-tree: $?\n";
460         print "Tree ID $tree\n" if $opt_v;
461
462         my $parent = "";
463         if(open(C,"$git_dir/refs/heads/$last_branch")) {
464                 chomp($parent = <C>);
465                 close(C);
466                 length($parent) == 40
467                         or die "Cannot get parent id ($parent): $!\n";
468                 print "Parent ID $parent\n" if $opt_v;
469         }
470
471         my $pr = IO::Pipe->new();
472         my $pw = IO::Pipe->new();
473         $pid = fork();
474         die "Fork: $!\n" unless defined $pid;
475         unless($pid) {
476                 $pr->writer();
477                 $pw->reader();
478                 dup2($pw->fileno(),0);
479                 dup2($pr->fileno(),1);
480                 $pr->close();
481                 $pw->close();
482
483                 my @par = ();
484                 @par = ("-p",$parent) if $parent;
485                 exec("env",
486                         "GIT_AUTHOR_NAME=$author",
487                         "GIT_AUTHOR_EMAIL=$author",
488                         "GIT_AUTHOR_DATE=".strftime("+0000 %Y-%m-%d %H:%M:%S",gmtime($date)),
489                         "GIT_COMMITTER_NAME=$author",
490                         "GIT_COMMITTER_EMAIL=$author",
491                         "GIT_COMMITTER_DATE=".strftime("+0000 %Y-%m-%d %H:%M:%S",gmtime($date)),
492                         "git-commit-tree", $tree,@par);
493                 die "Cannot exec git-commit-tree: $!\n";
494         }
495         $pw->writer();
496         $pr->reader();
497
498         # compatibility with git2cvs
499         substr($logmsg,32767) = "" if length($logmsg) > 32767;
500         $logmsg =~ s/[\s\n]+\z//;
501
502         print $pw "$logmsg\n"
503                 or die "Error writing to git-commit-tree: $!\n";
504         $pw->close();
505
506         print "Committed patch $patchset ($branch)\n" if $opt_v;
507         chomp(my $cid = <$pr>);
508         length($cid) == 40
509                 or die "Cannot get commit id ($cid): $!\n";
510         print "Commit ID $cid\n" if $opt_v;
511         $pr->close();
512
513         waitpid($pid,0);
514         die "Error running git-commit-tree: $?\n" if $?;
515
516         open(C,">$git_dir/refs/heads/$branch")
517                 or die "Cannot open branch $branch for update: $!\n";
518         print C "$cid\n"
519                 or die "Cannot write branch $branch for update: $!\n";
520         close(C)
521                 or die "Cannot write branch $branch for update: $!\n";
522
523         if($tag) {
524                 open(C,">$git_dir/refs/tags/$tag")
525                         or die "Cannot create tag $tag: $!\n";
526                 print C "$cid\n"
527                         or die "Cannot write tag $branch: $!\n";
528                 close(C)
529                         or die "Cannot write tag $branch: $!\n";
530                 print "Created tag '$tag' on '$branch'\n" if $opt_v;
531         }
532 };
533
534 while(<CVS>) {
535         chomp;
536         if($state == 0 and /^-+$/) {
537                 $state = 1;
538         } elsif($state == 0) {
539                 $state = 1;
540                 redo;
541         } elsif(($state==0 or $state==1) and s/^PatchSet\s+//) {
542                 $patchset = 0+$_;
543                 $state=2;
544         } elsif($state == 2 and s/^Date:\s+//) {
545                 $date = pdate($_);
546                 unless($date) {
547                         print STDERR "Could not parse date: $_\n";
548                         $state=0;
549                         next;
550                 }
551                 $state=3;
552         } elsif($state == 3 and s/^Author:\s+//) {
553                 s/\s+$//;
554                 $author = $_;
555                 $state = 4;
556         } elsif($state == 4 and s/^Branch:\s+//) {
557                 s/\s+$//;
558                 $branch = $_;
559                 $state = 5;
560         } elsif($state == 5 and s/^Ancestor branch:\s+//) {
561                 s/\s+$//;
562                 $ancestor = $_;
563                 $ancestor = $opt_o if $ancestor eq "HEAD";
564                 $state = 6;
565         } elsif($state == 5) {
566                 $ancestor = undef;
567                 $state = 6;
568                 redo;
569         } elsif($state == 6 and s/^Tag:\s+//) {
570                 s/\s+$//;
571                 if($_ eq "(none)") {
572                         $tag = undef;
573                 } else {
574                         $tag = $_;
575                 }
576                 $state = 7;
577         } elsif($state == 7 and /^Log:/) {
578                 $logmsg = "";
579                 $state = 8;
580         } elsif($state == 8 and /^Members:/) {
581                 $branch = $opt_o if $branch eq "HEAD";
582                 if(defined $branch_date{$branch} and $branch_date{$branch} >= $date) {
583                         # skip
584                         print "skip patchset $patchset: $date before $branch_date{$branch}\n";
585                         $state = 11;
586                         next;
587                 }
588                 if($ancestor) {
589                         if(-f "$git_dir/refs/heads/$branch") {
590                                 print STDERR "Branch $branch already exists!\n";
591                                 $state=11;
592                                 next;
593                         }
594                         unless(open(H,"$git_dir/refs/heads/$ancestor")) {
595                                 print STDERR "Branch $ancestor does not exist!\n";
596                                 $state=11;
597                                 next;
598                         }
599                         chomp(my $id = <H>);
600                         close(H);
601                         unless(open(H,"> $git_dir/refs/heads/$branch")) {
602                                 print STDERR "Could not create branch $branch: $!\n";
603                                 $state=11;
604                                 next;
605                         }
606                         print H "$id\n"
607                                 or die "Could not write branch $branch: $!";
608                         close(H)
609                                 or die "Could not write branch $branch: $!";
610                 }
611                 if(($ancestor || $branch) ne $last_branch) {
612                         print "Switching from $last_branch to $branch\n" if $opt_v;
613                         system("git-read-tree","-m","-u","$last_branch","$branch");
614                         die "read-tree failed: $?\n" if $?;
615                 }
616                 if($branch ne $last_branch) {
617                         unlink("$git_dir/HEAD");
618                         symlink("refs/heads/$branch","$git_dir/HEAD");
619                         $last_branch = $branch;
620                 }
621                 $state = 9;
622         } elsif($state == 8) {
623                 $logmsg .= "$_\n";
624         } elsif($state == 9 and /^\s+(\S+):(INITIAL|\d(?:\.\d+)+)->(\d(?:\.\d+)+)\s*$/) {
625 #       VERSION:1.96->1.96.2.1
626                 my $init = ($2 eq "INITIAL");
627                 my $fn = $1;
628                 my $rev = $3;
629                 $fn =~ s#^/+##;
630                 my $data = $cvs->file($fn,$rev);
631                 print "".($init ? "New" : "Update")." $fn: ".length($data)." bytes.\n";
632                 mkpath(dirname($fn),$opt_v);
633                 open(F,"> ./$fn")
634                         or die "Cannot create '$fn': $!\n";
635                 print F $data
636                         or die "Cannot write to '$fn': $!\n";
637                 close(F)
638                         or die "Cannot write to '$fn': $!\n";
639                 chmod(pmode($cvs->{'mode'}), $fn);
640                 push(@new,$fn); # may be resurrected!
641         } elsif($state == 9 and /^\s+(\S+):\d(?:\.\d+)+->(\d(?:\.\d+)+)\(DEAD\)\s*$/) {
642                 my $fn = $1;
643                 $fn =~ s#^/+##;
644                 push(@old,$fn);
645         } elsif($state == 9 and /^\s*$/) {
646                 $state = 10;
647         } elsif(($state == 9 or $state == 10) and /^-+$/) {
648                 &$commit();
649                 $state = 1;
650         } elsif($state == 11 and /^-+$/) {
651                 $state = 1;
652         } elsif(/^-+$/) { # end of unknown-line processing
653                 $state = 1;
654         } elsif($state != 11) { # ignore stuff when skipping
655                 print "* UNKNOWN LINE * $_\n";
656         }
657 }
658 &$commit() if $branch and $state != 11;
659
660 # Now switch back to the branch we were in before all of this happened
661 if($orig_branch) {
662         print "DONE; switching back to $orig_branch\n" if $opt_v;
663 } else {
664         $orig_branch = "master";
665         print "DONE; creating $orig_branch branch\n" if $opt_v;
666         system("cp","$git_dir/refs/heads/$opt_o","$git_dir/refs/heads/master")
667                 unless -f "$git_dir/refs/heads/master";
668 }
669
670 system("git-read-tree","-m","-u","$last_branch","$orig_branch");
671 die "read-tree failed: $?\n" if $?;
672
673 unlink("$git_dir/HEAD");
674 symlink("refs/heads/$orig_branch","$git_dir/HEAD");
675