Disambiguate the term 'branch' in Arch vs git
[git/git.git] / git-archimport.perl
1 #!/usr/bin/perl -w
2 #
3 # This tool is copyright (c) 2005, Martin Langhoff.
4 # It is released under the Gnu Public License, version 2.
5 #
6 # The basic idea is to walk the output of tla abrowse,
7 # fetch the changesets and apply them.
8 #
9
10 =head1 Invocation
11
12 git-archimport [ -h ] [ -v ] [ -T ] [ -t tempdir ] <archive>/<branch> [ <archive>/<branch> ]
13
14 Imports a project from one or more Arch repositories. It will follow branches
15 and repositories within the namespaces defined by the <archive/branch>
16 parameters suppplied. If it cannot find the remote branch a merge comes from
17 it will just import it as a regular commit. If it can find it, it will mark it
18 as a merge whenever possible.
19
20 See man (1) git-archimport for more details.
21
22 =head1 TODO
23
24 - create tag objects instead of ref tags
25 - audit shell-escaping of filenames
26 - hide our private tags somewhere smarter
27 - find a way to make "cat *patches | patch" safe even when patchfiles are missing newlines
28
29 =head1 Devel tricks
30
31 Add print in front of the shell commands invoked via backticks.
32
33 =head1 Devel Notes
34
35 There are several places where Arch and git terminology are intermixed
36 and potentially confused.
37
38 The notion of a "branch" in git is approximately equivalent to
39 a "archive/category--branch--version" in Arch. Also, it should be noted
40 that the "--branch" portion of "archive/category--branch--version" is really
41 optional in Arch although not many people (nor tools!) seem to know this.
42 This means that "archive/category--version" is also a valid "branch"
43 in git terms.
44
45 We always refer to Arch names by their fully qualified variant (which
46 means the "archive" name is prefixed.
47
48 For people unfamiliar with Arch, an "archive" is the term for "repository",
49 and can contain multiple, unrelated branches.
50
51 =cut
52
53 use strict;
54 use warnings;
55 use Getopt::Std;
56 use File::Spec;
57 use File::Temp qw(tempfile tempdir);
58 use File::Path qw(mkpath);
59 use File::Basename qw(basename dirname);
60 use String::ShellQuote;
61 use Time::Local;
62 use IO::Socket;
63 use IO::Pipe;
64 use POSIX qw(strftime dup2);
65 use Data::Dumper qw/ Dumper /;
66 use IPC::Open2;
67
68 $SIG{'PIPE'}="IGNORE";
69 $ENV{'TZ'}="UTC";
70
71 my $git_dir = $ENV{"GIT_DIR"} || ".git";
72 $ENV{"GIT_DIR"} = $git_dir;
73 my $ptag_dir = "$git_dir/archimport/tags";
74
75 our($opt_h,$opt_v, $opt_T,
76 $opt_C,$opt_t);
77
78 sub usage() {
79 print STDERR <<END;
80 Usage: ${\basename $0} # fetch/update GIT from Arch
81 [ -h ] [ -v ] [ -T ] [ -t tempdir ]
82 repository/arch-branch [ repository/arch-branch] ...
83 END
84 exit(1);
85 }
86
87 getopts("Thvt:") or usage();
88 usage if $opt_h;
89
90 @ARGV >= 1 or usage();
91 my @arch_roots = @ARGV;
92
93 my ($tmpdir, $tmpdirname) = tempdir('git-archimport-XXXXXX', TMPDIR => 1, CLEANUP => 1);
94 my $tmp = $opt_t || 1;
95 $tmp = tempdir('git-archimport-XXXXXX', TMPDIR => 1, CLEANUP => 1);
96 $opt_v && print "+ Using $tmp as temporary directory\n";
97
98 my @psets = (); # the collection
99 my %psets = (); # the collection, by name
100
101 my %rptags = (); # my reverse private tags
102 # to map a SHA1 to a commitid
103
104 foreach my $root (@arch_roots) {
105 my ($arepo, $abranch) = split(m!/!, $root);
106 open ABROWSE, "tla abrowse -f -A $arepo --desc --merges $abranch |"
107 or die "Problems with tla abrowse: $!";
108
109 my %ps = (); # the current one
110 my $mode = '';
111 my $lastseen = '';
112
113 while (<ABROWSE>) {
114 chomp;
115
116 # first record padded w 8 spaces
117 if (s/^\s{8}\b//) {
118
119 # store the record we just captured
120 if (%ps) {
121 my %temp = %ps; # break references
122 push (@psets, \%temp);
123 $psets{$temp{id}} = \%temp;
124 %ps = ();
125 }
126
127 my ($id, $type) = split(m/\s{3}/, $_);
128 $ps{id} = $id;
129 $ps{repo} = $arepo;
130
131 # deal with types
132 if ($type =~ m/^\(simple changeset\)/) {
133 $ps{type} = 's';
134 } elsif ($type eq '(initial import)') {
135 $ps{type} = 'i';
136 } elsif ($type =~ m/^\(tag revision of (.+)\)/) {
137 $ps{type} = 't';
138 $ps{tag} = $1;
139 } else {
140 warn "Unknown type $type";
141 }
142 $lastseen = 'id';
143 }
144
145 if (s/^\s{10}//) {
146 # 10 leading spaces or more
147 # indicate commit metadata
148
149 # date & author
150 if ($lastseen eq 'id' && m/^\d{4}-\d{2}-\d{2}/) {
151
152 my ($date, $authoremail) = split(m/\s{2,}/, $_);
153 $ps{date} = $date;
154 $ps{date} =~ s/\bGMT$//; # strip off trailign GMT
155 if ($ps{date} =~ m/\b\w+$/) {
156 warn 'Arch dates not in GMT?! - imported dates will be wrong';
157 }
158
159 $authoremail =~ m/^(.+)\s(\S+)$/;
160 $ps{author} = $1;
161 $ps{email} = $2;
162
163 $lastseen = 'date';
164
165 } elsif ($lastseen eq 'date') {
166 # the only hint is position
167 # subject is after date
168 $ps{subj} = $_;
169 $lastseen = 'subj';
170
171 } elsif ($lastseen eq 'subj' && $_ eq 'merges in:') {
172 $ps{merges} = [];
173 $lastseen = 'merges';
174
175 } elsif ($lastseen eq 'merges' && s/^\s{2}//) {
176 push (@{$ps{merges}}, $_);
177 } else {
178 warn 'more metadata after merges!?';
179 }
180
181 }
182 }
183
184 if (%ps) {
185 my %temp = %ps; # break references
186 push (@psets, \%temp);
187 $psets{ $temp{id} } = \%temp;
188 %ps = ();
189 }
190 close ABROWSE;
191 } # end foreach $root
192
193 ## Order patches by time
194 @psets = sort {$a->{date}.$b->{id} cmp $b->{date}.$b->{id}} @psets;
195
196 #print Dumper \@psets;
197
198 ##
199 ## TODO cleanup irrelevant patches
200 ## and put an initial import
201 ## or a full tag
202 my $import = 0;
203 unless (-d $git_dir) { # initial import
204 if ($psets[0]{type} eq 'i' || $psets[0]{type} eq 't') {
205 print "Starting import from $psets[0]{id}\n";
206 `git-init-db`;
207 die $! if $?;
208 $import = 1;
209 } else {
210 die "Need to start from an import or a tag -- cannot use $psets[0]{id}";
211 }
212 } else { # progressing an import
213 # load the rptags
214 opendir(DIR, "$git_dir/archimport/tags")
215 || die "can't opendir: $!";
216 while (my $file = readdir(DIR)) {
217 # skip non-interesting-files
218 next unless -f "$ptag_dir/$file";
219
220 # convert first '--' to '/' from old git-archimport to use
221 # as an archivename/c--b--v private tag
222 if ($file !~ m!,!) {
223 my $oldfile = $file;
224 $file =~ s!--!,!;
225 print STDERR "converting old tag $oldfile to $file\n";
226 rename("$ptag_dir/$oldfile", "$ptag_dir/$file") or die $!;
227 }
228 my $sha = ptag($file);
229 chomp $sha;
230 $rptags{$sha} = $file;
231 }
232 closedir DIR;
233 }
234
235 # process patchsets
236 # extract the Arch repository name (Arch "archive" in Arch-speak)
237 sub extract_reponame {
238 my $fq_cvbr = shift; # archivename/[[[[category]branch]version]revision]
239 return (split(/\//, $fq_cvbr))[0];
240 }
241
242 sub extract_versionname {
243 my $name = shift;
244 $name =~ s/--(?:patch|version(?:fix)?|base)-\d+$//;
245 return $name;
246 }
247
248 # convert a fully-qualified revision or version to a unique dirname:
249 # normalperson@yhbt.net-05/mpd--uclinux--1--patch-2
250 # becomes: normalperson@yhbt.net-05,mpd--uclinux--1
251 #
252 # the git notion of a branch is closer to
253 # archive/category--branch--version than archive/category--branch, so we
254 # use this to convert to git branch names.
255 # Also, keep archive names but replace '/' with ',' since it won't require
256 # subdirectories, and is safer than swapping '--' which could confuse
257 # reverse-mapping when dealing with bastard branches that
258 # are just archive/category--version (no --branch)
259 sub tree_dirname {
260 my $revision = shift;
261 my $name = extract_versionname($revision);
262 $name =~ s#/#,#;
263 return $name;
264 }
265
266 *git_branchname = *tree_dirname;
267
268 # process patchsets
269 foreach my $ps (@psets) {
270 $ps->{branch} = git_branchname($ps->{id});
271
272 #
273 # ensure we have a clean state
274 #
275 if (`git diff-files`) {
276 die "Unclean tree when about to process $ps->{id} " .
277 " - did we fail to commit cleanly before?";
278 }
279 die $! if $?;
280
281 #
282 # skip commits already in repo
283 #
284 if (ptag($ps->{id})) {
285 $opt_v && print " * Skipping already imported: $ps->{id}\n";
286 next;
287 }
288
289 print " * Starting to work on $ps->{id}\n";
290
291 #
292 # create the branch if needed
293 #
294 if ($ps->{type} eq 'i' && !$import) {
295 die "Should not have more than one 'Initial import' per GIT import: $ps->{id}";
296 }
297
298 unless ($import) { # skip for import
299 if ( -e "$git_dir/refs/heads/$ps->{branch}") {
300 # we know about this branch
301 `git checkout $ps->{branch}`;
302 } else {
303 # new branch! we need to verify a few things
304 die "Branch on a non-tag!" unless $ps->{type} eq 't';
305 my $branchpoint = ptag($ps->{tag});
306 die "Tagging from unknown id unsupported: $ps->{tag}"
307 unless $branchpoint;
308
309 # find where we are supposed to branch from
310 `git checkout -b $ps->{branch} $branchpoint`;
311
312 # If we trust Arch with the fact that this is just
313 # a tag, and it does not affect the state of the tree
314 # then we just tag and move on
315 tag($ps->{id}, $branchpoint);
316 ptag($ps->{id}, $branchpoint);
317 print " * Tagged $ps->{id} at $branchpoint\n";
318 next;
319 }
320 die $! if $?;
321 }
322
323 #
324 # Apply the import/changeset/merge into the working tree
325 #
326 if ($ps->{type} eq 'i' || $ps->{type} eq 't') {
327 apply_import($ps) or die $!;
328 $import=0;
329 } elsif ($ps->{type} eq 's') {
330 apply_cset($ps);
331 }
332
333 #
334 # prepare update git's index, based on what arch knows
335 # about the pset, resolve parents, etc
336 #
337 my $tree;
338
339 my $commitlog = `tla cat-archive-log -A $ps->{repo} $ps->{id}`;
340 die "Error in cat-archive-log: $!" if $?;
341
342 # parselog will git-add/rm files
343 # and generally prepare things for the commit
344 # NOTE: parselog will shell-quote filenames!
345 my ($sum, $msg, $add, $del, $mod, $ren) = parselog($commitlog);
346 my $logmessage = "$sum\n$msg";
347
348
349 # imports don't give us good info
350 # on added files. Shame on them
351 if ($ps->{type} eq 'i' || $ps->{type} eq 't') {
352 `find . -type f -print0 | grep -zv '^./$git_dir' | xargs -0 -l100 git-update-index --add`;
353 `git-ls-files --deleted -z | xargs --no-run-if-empty -0 -l100 git-update-index --remove`;
354 }
355
356 if (@$add) {
357 while (@$add) {
358 my @slice = splice(@$add, 0, 100);
359 my $slice = join(' ', @slice);
360 `git-update-index --add $slice`;
361 die "Error in git-update-index --add: $!" if $?;
362 }
363 }
364 if (@$del) {
365 foreach my $file (@$del) {
366 unlink $file or die "Problems deleting $file : $!";
367 }
368 while (@$del) {
369 my @slice = splice(@$del, 0, 100);
370 my $slice = join(' ', @slice);
371 `git-update-index --remove $slice`;
372 die "Error in git-update-index --remove: $!" if $?;
373 }
374 }
375 if (@$ren) { # renamed
376 if (@$ren % 2) {
377 die "Odd number of entries in rename!?";
378 }
379 ;
380 while (@$ren) {
381 my $from = pop @$ren;
382 my $to = pop @$ren;
383
384 unless (-d dirname($to)) {
385 mkpath(dirname($to)); # will die on err
386 }
387 #print "moving $from $to";
388 `mv $from $to`;
389 die "Error renaming $from $to : $!" if $?;
390 `git-update-index --remove $from`;
391 die "Error in git-update-index --remove: $!" if $?;
392 `git-update-index --add $to`;
393 die "Error in git-update-index --add: $!" if $?;
394 }
395
396 }
397 if (@$mod) { # must be _after_ renames
398 while (@$mod) {
399 my @slice = splice(@$mod, 0, 100);
400 my $slice = join(' ', @slice);
401 `git-update-index $slice`;
402 die "Error in git-update-index: $!" if $?;
403 }
404 }
405
406 # warn "errors when running git-update-index! $!";
407 $tree = `git-write-tree`;
408 die "cannot write tree $!" if $?;
409 chomp $tree;
410
411
412 #
413 # Who's your daddy?
414 #
415 my @par;
416 if ( -e "$git_dir/refs/heads/$ps->{branch}") {
417 if (open HEAD, "<$git_dir/refs/heads/$ps->{branch}") {
418 my $p = <HEAD>;
419 close HEAD;
420 chomp $p;
421 push @par, '-p', $p;
422 } else {
423 if ($ps->{type} eq 's') {
424 warn "Could not find the right head for the branch $ps->{branch}";
425 }
426 }
427 }
428
429 if ($ps->{merges}) {
430 push @par, find_parents($ps);
431 }
432 my $par = join (' ', @par);
433
434 #
435 # Commit, tag and clean state
436 #
437 $ENV{TZ} = 'GMT';
438 $ENV{GIT_AUTHOR_NAME} = $ps->{author};
439 $ENV{GIT_AUTHOR_EMAIL} = $ps->{email};
440 $ENV{GIT_AUTHOR_DATE} = $ps->{date};
441 $ENV{GIT_COMMITTER_NAME} = $ps->{author};
442 $ENV{GIT_COMMITTER_EMAIL} = $ps->{email};
443 $ENV{GIT_COMMITTER_DATE} = $ps->{date};
444
445 my ($pid, $commit_rh, $commit_wh);
446 $commit_rh = 'commit_rh';
447 $commit_wh = 'commit_wh';
448
449 $pid = open2(*READER, *WRITER, "git-commit-tree $tree $par")
450 or die $!;
451 print WRITER $logmessage; # write
452 close WRITER;
453 my $commitid = <READER>; # read
454 chomp $commitid;
455 close READER;
456 waitpid $pid,0; # close;
457
458 if (length $commitid != 40) {
459 die "Something went wrong with the commit! $! $commitid";
460 }
461 #
462 # Update the branch
463 #
464 open HEAD, ">$git_dir/refs/heads/$ps->{branch}";
465 print HEAD $commitid;
466 close HEAD;
467 system('git-update-ref', 'HEAD', "$ps->{branch}");
468
469 # tag accordingly
470 ptag($ps->{id}, $commitid); # private tag
471 if ($opt_T || $ps->{type} eq 't' || $ps->{type} eq 'i') {
472 tag($ps->{id}, $commitid);
473 }
474 print " * Committed $ps->{id}\n";
475 print " + tree $tree\n";
476 print " + commit $commitid\n";
477 $opt_v && print " + commit date is $ps->{date} \n";
478 $opt_v && print " + parents: $par \n";
479 }
480
481 sub apply_import {
482 my $ps = shift;
483 my $bname = git_branchname($ps->{id});
484
485 `mkdir -p $tmp`;
486
487 `tla get -s --no-pristine -A $ps->{repo} $ps->{id} $tmp/import`;
488 die "Cannot get import: $!" if $?;
489 `rsync -v --archive --delete --exclude '$git_dir' --exclude '.arch-ids' --exclude '{arch}' $tmp/import/* ./`;
490 die "Cannot rsync import:$!" if $?;
491
492 `rm -fr $tmp/import`;
493 die "Cannot remove tempdir: $!" if $?;
494
495
496 return 1;
497 }
498
499 sub apply_cset {
500 my $ps = shift;
501
502 `mkdir -p $tmp`;
503
504 # get the changeset
505 `tla get-changeset -A $ps->{repo} $ps->{id} $tmp/changeset`;
506 die "Cannot get changeset: $!" if $?;
507
508 # apply patches
509 if (`find $tmp/changeset/patches -type f -name '*.patch'`) {
510 # this can be sped up considerably by doing
511 # (find | xargs cat) | patch
512 # but that cna get mucked up by patches
513 # with missing trailing newlines or the standard
514 # 'missing newline' flag in the patch - possibly
515 # produced with an old/buggy diff.
516 # slow and safe, we invoke patch once per patchfile
517 `find $tmp/changeset/patches -type f -name '*.patch' -print0 | grep -zv '{arch}' | xargs -iFILE -0 --no-run-if-empty patch -p1 --forward -iFILE`;
518 die "Problem applying patches! $!" if $?;
519 }
520
521 # apply changed binary files
522 if (my @modified = `find $tmp/changeset/patches -type f -name '*.modified'`) {
523 foreach my $mod (@modified) {
524 chomp $mod;
525 my $orig = $mod;
526 $orig =~ s/\.modified$//; # lazy
527 $orig =~ s!^\Q$tmp\E/changeset/patches/!!;
528 #print "rsync -p '$mod' '$orig'";
529 `rsync -p $mod ./$orig`;
530 die "Problem applying binary changes! $!" if $?;
531 }
532 }
533
534 # bring in new files
535 `rsync --archive --exclude '$git_dir' --exclude '.arch-ids' --exclude '{arch}' $tmp/changeset/new-files-archive/* ./`;
536
537 # deleted files are hinted from the commitlog processing
538
539 `rm -fr $tmp/changeset`;
540 }
541
542
543 # =for reference
544 # A log entry looks like
545 # Revision: moodle-org--moodle--1.3.3--patch-15
546 # Archive: arch-eduforge@catalyst.net.nz--2004
547 # Creator: Penny Leach <penny@catalyst.net.nz>
548 # Date: Wed May 25 14:15:34 NZST 2005
549 # Standard-date: 2005-05-25 02:15:34 GMT
550 # New-files: lang/de/.arch-ids/block_glossary_random.php.id
551 # lang/de/.arch-ids/block_html.php.id
552 # New-directories: lang/de/help/questionnaire
553 # lang/de/help/questionnaire/.arch-ids
554 # Renamed-files: .arch-ids/db_sears.sql.id db/.arch-ids/db_sears.sql.id
555 # db_sears.sql db/db_sears.sql
556 # Removed-files: lang/be/docs/.arch-ids/release.html.id
557 # lang/be/docs/.arch-ids/releaseold.html.id
558 # Modified-files: admin/cron.php admin/delete.php
559 # admin/editor.html backup/lib.php backup/restore.php
560 # New-patches: arch-eduforge@catalyst.net.nz--2004/moodle-org--moodle--1.3.3--patch-15
561 # Summary: Updating to latest from MOODLE_14_STABLE (1.4.5+)
562 # Keywords:
563 #
564 # Updating yadda tadda tadda madda
565 sub parselog {
566 my $log = shift;
567 #print $log;
568
569 my (@add, @del, @mod, @ren, @kw, $sum, $msg );
570
571 if ($log =~ m/(?:\n|^)New-files:(.*?)(?=\n\w)/s ) {
572 my $files = $1;
573 @add = split(m/\s+/s, $files);
574 }
575
576 if ($log =~ m/(?:\n|^)Removed-files:(.*?)(?=\n\w)/s ) {
577 my $files = $1;
578 @del = split(m/\s+/s, $files);
579 }
580
581 if ($log =~ m/(?:\n|^)Modified-files:(.*?)(?=\n\w)/s ) {
582 my $files = $1;
583 @mod = split(m/\s+/s, $files);
584 }
585
586 if ($log =~ m/(?:\n|^)Renamed-files:(.*?)(?=\n\w)/s ) {
587 my $files = $1;
588 @ren = split(m/\s+/s, $files);
589 }
590
591 $sum ='';
592 if ($log =~ m/^Summary:(.+?)$/m ) {
593 $sum = $1;
594 $sum =~ s/^\s+//;
595 $sum =~ s/\s+$//;
596 }
597
598 $msg = '';
599 if ($log =~ m/\n\n(.+)$/s) {
600 $msg = $1;
601 $msg =~ s/^\s+//;
602 $msg =~ s/\s+$//;
603 }
604
605
606 # cleanup the arrays
607 foreach my $ref ( (\@add, \@del, \@mod, \@ren) ) {
608 my @tmp = ();
609 while (my $t = pop @$ref) {
610 next unless length ($t);
611 next if $t =~ m!\{arch\}/!;
612 next if $t =~ m!\.arch-ids/!;
613 next if $t =~ m!\.arch-inventory$!;
614 # tla cat-archive-log will give us filenames with spaces as file\(sp)name - why?
615 # we can assume that any filename with \ indicates some pika escaping that we want to get rid of.
616 if ($t =~ /\\/ ){
617 $t = `tla escape --unescaped '$t'`;
618 }
619 push (@tmp, shell_quote($t));
620 }
621 @$ref = @tmp;
622 }
623
624 #print Dumper [$sum, $msg, \@add, \@del, \@mod, \@ren];
625 return ($sum, $msg, \@add, \@del, \@mod, \@ren);
626 }
627
628 # write/read a tag
629 sub tag {
630 my ($tag, $commit) = @_;
631
632 # don't use subdirs for tags yet, it could screw up other porcelains
633 $tag =~ s|/|,|;
634
635 if ($commit) {
636 open(C,">","$git_dir/refs/tags/$tag")
637 or die "Cannot create tag $tag: $!\n";
638 print C "$commit\n"
639 or die "Cannot write tag $tag: $!\n";
640 close(C)
641 or die "Cannot write tag $tag: $!\n";
642 print " * Created tag '$tag' on '$commit'\n" if $opt_v;
643 } else { # read
644 open(C,"<","$git_dir/refs/tags/$tag")
645 or die "Cannot read tag $tag: $!\n";
646 $commit = <C>;
647 chomp $commit;
648 die "Error reading tag $tag: $!\n" unless length $commit == 40;
649 close(C)
650 or die "Cannot read tag $tag: $!\n";
651 return $commit;
652 }
653 }
654
655 # write/read a private tag
656 # reads fail softly if the tag isn't there
657 sub ptag {
658 my ($tag, $commit) = @_;
659
660 # don't use subdirs for tags yet, it could screw up other porcelains
661 $tag =~ s|/|,|g;
662
663 my $tag_file = "$ptag_dir/$tag";
664 my $tag_branch_dir = dirname($tag_file);
665 mkpath($tag_branch_dir) unless (-d $tag_branch_dir);
666
667 if ($commit) { # write
668 open(C,">",$tag_file)
669 or die "Cannot create tag $tag: $!\n";
670 print C "$commit\n"
671 or die "Cannot write tag $tag: $!\n";
672 close(C)
673 or die "Cannot write tag $tag: $!\n";
674 $rptags{$commit} = $tag
675 unless $tag =~ m/--base-0$/;
676 } else { # read
677 # if the tag isn't there, return 0
678 unless ( -s $tag_file) {
679 return 0;
680 }
681 open(C,"<",$tag_file)
682 or die "Cannot read tag $tag: $!\n";
683 $commit = <C>;
684 chomp $commit;
685 die "Error reading tag $tag: $!\n" unless length $commit == 40;
686 close(C)
687 or die "Cannot read tag $tag: $!\n";
688 unless (defined $rptags{$commit}) {
689 $rptags{$commit} = $tag;
690 }
691 return $commit;
692 }
693 }
694
695 sub find_parents {
696 #
697 # Identify what branches are merging into me
698 # and whether we are fully merged
699 # git-merge-base <headsha> <headsha> should tell
700 # me what the base of the merge should be
701 #
702 my $ps = shift;
703
704 my %branches; # holds an arrayref per branch
705 # the arrayref contains a list of
706 # merged patches between the base
707 # of the merge and the current head
708
709 my @parents; # parents found for this commit
710
711 # simple loop to split the merges
712 # per branch
713 foreach my $merge (@{$ps->{merges}}) {
714 my $branch = git_branchname($merge);
715 unless (defined $branches{$branch} ){
716 $branches{$branch} = [];
717 }
718 push @{$branches{$branch}}, $merge;
719 }
720
721 #
722 # foreach branch find a merge base and walk it to the
723 # head where we are, collecting the merged patchsets that
724 # Arch has recorded. Keep that in @have
725 # Compare that with the commits on the other branch
726 # between merge-base and the tip of the branch (@need)
727 # and see if we have a series of consecutive patches
728 # starting from the merge base. The tip of the series
729 # of consecutive patches merged is our new parent for
730 # that branch.
731 #
732 foreach my $branch (keys %branches) {
733
734 # check that we actually know about the branch
735 next unless -e "$git_dir/refs/heads/$branch";
736
737 my $mergebase = `git-merge-base $branch $ps->{branch}`;
738 if ($?) {
739 # Don't die here, Arch supports one-way cherry-picking
740 # between branches with no common base (or any relationship
741 # at all beforehand)
742 warn "Cannot find merge base for $branch and $ps->{branch}";
743 next;
744 }
745 chomp $mergebase;
746
747 # now walk up to the mergepoint collecting what patches we have
748 my $branchtip = git_rev_parse($ps->{branch});
749 my @ancestors = `git-rev-list --merge-order $branchtip ^$mergebase`;
750 my %have; # collected merges this branch has
751 foreach my $merge (@{$ps->{merges}}) {
752 $have{$merge} = 1;
753 }
754 my %ancestorshave;
755 foreach my $par (@ancestors) {
756 $par = commitid2pset($par);
757 if (defined $par->{merges}) {
758 foreach my $merge (@{$par->{merges}}) {
759 $ancestorshave{$merge}=1;
760 }
761 }
762 }
763 # print "++++ Merges in $ps->{id} are....\n";
764 # my @have = sort keys %have; print Dumper(\@have);
765
766 # merge what we have with what ancestors have
767 %have = (%have, %ancestorshave);
768
769 # see what the remote branch has - these are the merges we
770 # will want to have in a consecutive series from the mergebase
771 my $otherbranchtip = git_rev_parse($branch);
772 my @needraw = `git-rev-list --merge-order $otherbranchtip ^$mergebase`;
773 my @need;
774 foreach my $needps (@needraw) { # get the psets
775 $needps = commitid2pset($needps);
776 # git-rev-list will also
777 # list commits merged in via earlier
778 # merges. we are only interested in commits
779 # from the branch we're looking at
780 if ($branch eq $needps->{branch}) {
781 push @need, $needps->{id};
782 }
783 }
784
785 # print "++++ Merges from $branch we want are....\n";
786 # print Dumper(\@need);
787
788 my $newparent;
789 while (my $needed_commit = pop @need) {
790 if ($have{$needed_commit}) {
791 $newparent = $needed_commit;
792 } else {
793 last; # break out of the while
794 }
795 }
796 if ($newparent) {
797 push @parents, $newparent;
798 }
799
800
801 } # end foreach branch
802
803 # prune redundant parents
804 my %parents;
805 foreach my $p (@parents) {
806 $parents{$p} = 1;
807 }
808 foreach my $p (@parents) {
809 next unless exists $psets{$p}{merges};
810 next unless ref $psets{$p}{merges};
811 my @merges = @{$psets{$p}{merges}};
812 foreach my $merge (@merges) {
813 if ($parents{$merge}) {
814 delete $parents{$merge};
815 }
816 }
817 }
818 @parents = keys %parents;
819 @parents = map { " -p " . ptag($_) } @parents;
820 return @parents;
821 }
822
823 sub git_rev_parse {
824 my $name = shift;
825 my $val = `git-rev-parse $name`;
826 die "Error: git-rev-parse $name" if $?;
827 chomp $val;
828 return $val;
829 }
830
831 # resolve a SHA1 to a known patchset
832 sub commitid2pset {
833 my $commitid = shift;
834 chomp $commitid;
835 my $name = $rptags{$commitid}
836 || die "Cannot find reverse tag mapping for $commitid";
837 $name =~ s|,|/|;
838 my $ps = $psets{$name}
839 || (print Dumper(sort keys %psets)) && die "Cannot find patchset for $name";
840 return $ps;
841 }