Charvi Mendiratta <charvi077@xxxxxxxxx> writes: > `git commit --fixup=amend:<commit>` will create an "amend!" commit. > The resulting commit message subject will be "amend! ..." where > "..." is the subject line of <commit> and the initial message > body will be <commit>'s message. -m can be used to override the > message body. > > The "amend!" commit when rebased with --autosquash will fixup the > contents and replace the commit message of <commit> with the > "amend!" commit's message body. > > Inorder to prevent rebase from creating commits with an empty > message we refuse to create an "amend!" commit if commit message > body is empty. > > Example usage: > $ git commit --fixup=amend:HEAD > $ git commit --fixup=amend:HEAD -m "clever commit message" Sorry, but it is not so clear what these examples are trying to illustrate. The first one is to add a new commit to later amend the tip commit (It is a bit of mystery why the user does not do a more usual "git commit --amend" right there, though, and such a mystery may distract readers. If the commit were not at the tip, e.g. HEAD~3, it may be less distracting). The second one, even with s|HEAD|HEAD~3| is even less clear. Without the "-m", the resulting commit will have the subject that begins with !amend but the log message body is taken from the given commit, but with "-m", what happens? Does a single-liner 'clever commit message' _replace_ the log message of the named commit, resulting in an !amend commit that has no message from the original? Or does 'clever commit message' get _appended_ the log message? I think we can just remove the "example" from here and explain the feature well in the end-user facing documentation. > + if (fixup_message) { > + /* > + * check if ':' occurs before '^' or '@', otherwise > + * fixup_message is a commit reference. > + */ Isn't it that you only intend to parse: --fixup --fixup=amend:<any string that names a commit> --fixup=<any string that names a commit> and later extend it to allow keywords other than "amend"? I can understand that you are trying to avoid getting fooled by things like --fixup='HEAD^{/commit message with a colon : in it}' but why special case only ^ and @? This feels brittle (note that I said "things like", exactly because I do not know if any string that can name a commit must have "@" or "^" appear before ":" if it is to have ":" in anywhere, which is what this code assumes). Instead, you can find the first colon, check for known keywords (or a string that consists only of alnums to accomodate for future enhancement), and treat any garbage that happens to have a colon without the "keyword" as fixup_commit. I.e. something along this line... const char alphas[] = "abcde...xyz"; size_t kwd_len; kwd_len = strspn(fixup_message, alphas); if (kwd_len && fixup_message[kwd_len] == ':') { /* found keyword? */ fixup_message[kwd_len] = '\0'; if (!strcmp("amend", fixup_message)) { ... do the amend:<commit> thing ... #if in-next-step-when-you-add-support-for-reword } else if (!strcmp("reword", fixup_message)) { ... do the reword:<commit> thing ... #endif } else { die(_("unknown --fixup=%s:<commit>", fixup_message)); } } else { /* the entire fixup_message is the commit */ }