On Thu, Feb 28, 2019 at 11:02:11AM +0100, Max Filenko wrote: > Subject: [PATCH] :::: four colons prepended > [...] > There will be no colons in the beginning of a commit message if I apply > this patch: > > $ git am 0001-four-colons-prepended.patch > Applying: four colons prepended I suspect this has to do with the sanitization that happens as part of removing "[PATCH]". Note that if you use "-k" (to preserve the subject) it doesn't happen, though of course you also get "[PATCH]" then. If you want to pass the subject lines through verbatim, use "-k" with both format-patch and git-am. > I was able to trace this down to <builtin/am.c>. It seems like there are > no colons already in the `state->msg' which to my understanding is being > filled by `read_commit_msg()' function. I would really appreciate a hand > on debugging it further. It's probably easier to debug with git-mailinfo, which has the same behavior: $ git mailinfo msg patch <0001-four-colons-prepended.patch Author: Jeff King Email: peff@xxxxxxxx Subject: four colons prepended Date: Thu, 28 Feb 2019 06:12:50 -0500 and is based on the same routines. The contents are preserved until we end up in mailinfo.c's cleanup_subject(). And there leading colons are explicitly removed: case ' ': case '\t': case ':': strbuf_remove(subject, at, 1); continue; That behavior goes all the way back to 2744b2344d (Start of early patch applicator tools for git., 2005-04-11), when Git was only 4 days old. Since it also handles cruft like "Re:", I suspect the goal there was I suspect the goal there was to remove cruft like "Re::::" or "Re: :" which sometimes happens. I don't know if anybody would complain if we were more careful about leaving lone colons that weren't part of a "Re" chain. -Peff