# Migration from CVS to Git looses merges 3 messages from 2017-06-25 to 2017-06-25. Participants: Urs Thuermann, Andreas Schwab. Thread: https://gitlist.dev/t/46254 ## Urs Thuermann, 2017-06-25 07:12 Subject: Migration from CVS to Git looses merges Message-ID: URL: https://gitlist.dev/e/ygfd19stua3.fsf%40tehran.isnogud.escape.de ``` I want to convert several old CVS repositories to Git. Some of these CVS repositories contain branches, which have later been merged to the main trunk. When I try to convert using cvs2git or git cvsimport the branches appear in the new git repository but they are not merged to the master branch. Here is an example of how the branches in the CVS repository were created and merged: cd /tmp export CVSROOT=$PWD/CVS cvs init mkdir CVS/foo cvs co foo cd foo (date; seq 10; date) > bar cvs add bar cvs ci -m msg1 # rev 1.1 sleep 1 printf "1c\n%s\n.\nwq\n" "`date`" | ed bar cvs ci -m msg2 # rev 1.2 sleep 1 cvs tag -b a-branch sleep 1 printf "1c\n%s\n.\nwq\n" "`date`" | ed bar cvs ci -m msg3 # rev 1.3 sleep 1 cvs up -r a-branch printf "12c\n%s\n.\nwq\n" "`date`" | ed bar cvs ci -m msg-b1 # rev 1.2.2.1 sleep 1 printf "12c\n%s\n.\nwq\n" "`date`" | ed bar cvs ci -m msg-b2 # rev 1.2.2.2 sleep 1 cvs up -A cvs up -j a-branch cvs ci -m "Merge branch a-branch" # rev 1.4 Now I have tried 2 ways to convert this to git: 1. mkdir g; cd g; git cvsimport -A -m foo 2. mkdir g; cd g; git init; cvs2git --blobfile=foo.blob --dumpfile=foo.dump --username=urs ../CVS/foo cat foo.blob foo.dump | git fast-import In both cases, the branch "a-branch" is in the git repository but is not merged with the master branch, i.e. rev 1.4 has only parent 1.3 but not 1.2.2.2. I also tried cvsimport with several regexes passed using -M to match "Merge branch a-branch", but still the same result. How should the CVS repository be converted to git, so that the commit corresponding to rev 1.4 has two parents, 1.3 and 1.2.2.2? urs ``` ## Andreas Schwab, 2017-06-25 08:13 Subject: Re: Migration from CVS to Git looses merges Message-ID: <87a84web83.fsf@linux-m68k.org> URL: https://gitlist.dev/e/87a84web83.fsf%40linux-m68k.org In-Reply-To: ``` On Jun 25 2017, Urs Thuermann wrote: > In both cases, the branch "a-branch" is in the git repository but is > not merged with the master branch, i.e. rev 1.4 has only parent 1.3 > but not 1.2.2.2. I also tried cvsimport with several regexes passed > using -M to match "Merge branch a-branch", but still the same result. Merges are recognized purely by matching the commit message, and the regexp must capture the branch name in the first subexpr. The -m option enables some default regexps but won't match your example. You can use -M 'Merge branch ([-\w]+)' to match it. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ``` ## Urs Thuermann, 2017-06-25 09:30 Subject: Re: Migration from CVS to Git looses merges Message-ID: URL: https://gitlist.dev/e/ygf7f00tnwh.fsf%40tehran.isnogud.escape.de In-Reply-To: <87a84web83.fsf@linux-m68k.org> ``` Andreas Schwab writes: > Merges are recognized purely by matching the commit message, and the > regexp must capture the branch name in the first subexpr. The -m option > enables some default regexps but won't match your example. You can use > -M 'Merge branch ([-\w]+)' to match it. Thanks, I tried again and now it works. I misread the man page and also tried enclosing the regexp in //, also tried to escape the parentheses (as in BRE), and I thought I also tried 'Merge branch (.*)'. Obviously, I missed that one since it now works. BTW, I now looked up the regexes for -m in git-cvsimport.perl. Should probably in the man page. I also suggest the following patch, so that -m would work with my not so uncommon merge commit message: diff --git a/git-cvsimport.perl b/git-cvsimport.perl index 1e4e65a..1f8044b 100755 --- a/git-cvsimport.perl +++ b/git-cvsimport.perl @@ -207,7 +207,7 @@ if ($#ARGV == 0) { our @mergerx = (); if ($opt_m) { - @mergerx = ( qr/\b(?:from|of|merge|merging|merged) ([-\w]+)/i ); + @mergerx = ( qr/\b(?:from|of|merge|merging|merged) (?:branch )?([-\w]+)/i ); } if (@opt_M) { push (@mergerx, map { qr/$_/ } @opt_M); urs ```