Hello Philippe, Thank you for your reply, and the points to the mailing list. >Thanks for the reproducer. The behaviour for 'git log/show/diff' is due this line >and the behaviour for 'git submodule summary' to these lines. > >For 'git diff' and friends, it goes back to the addition of the '--submodule=log' >option in 752c0c2492 (Add the --submodule option to the diff option family, 2009-10-19). >(authored CC'ed). The use of '--first-parent' was discussed on the list >when this was implemented. I did not read the whole thing. > >For 'git submodule summary', it goes back to the addition of the subcommand >in 1cb639e6b0 (git-submodule summary: show commit summary, 2008-03-11). (author also CC'ed). >The justification of the use of '--first-parent' was not really discussed >as far as I could tell. > > >I personnally think it would be a good addition to be able to choose >if yes or no '--first-parent' should be used The discussion you found [1] also suggested that as a future option. In the original implementation, the first mention is [2], where the length of the message is discussed - I (and later discussions) assume that this just happened to be the preference of the author. I would thus like to correct myself, and refile this as a feature request - it would be very helpful to me to have this as an option, possibly even with one that can be set in the config, similar to 'diff.submodule=log'. I would be open to implementing this - I might need some mentoring, however, as this would be my first time contributing (and reading the git codebase). Regards, Mel [1] https://lore.kernel.org/git/67a884457aeaead275612be10902a80726b2a7db.1254668669u.git.johannes.schindelin@xxxxxx/t/#u [2] https://lore.kernel.org/git/46dff0320803061750x70d059a2yaf1e5751e9c62150@xxxxxxxxxxxxxx/