Jeff King <p...@peff.net> writes: > On Thu, May 22, 2014 at 11:33:04PM +0200, Christian Couder wrote: > >> The usage string for this option is: >> >> git replace [-f] --graft <commit> [<parent>...] >> >> First we create a new commit that is the same as <commit> >> except that its parents are [<parents>...] >> >> Then we create a replace ref that replace <commit> with >> the commit we just created. >> >> With this new option, it should be straightforward to >> convert grafts to replace refs, with something like: >> >> cat .git/info/grafts | while read line >> do git replace --graft $line; done > > I think this script at the end should end up in the documentation or a > contrib script (probably the former, as it is short enough that somebody > might just cut-and-paste). > > The graft file ignores comments and blank lines, so maybe "grep '^[^#]'" > would be in order. > > And maybe it's just me, but I think spacing it like: > > grep '^[^#]' .git/info/grafts | > while read line; do > git replace --graft $line > done > > is more readable (I think some would even argue for putting the "do" on > a separate line).
Yes, I would ;-) I just read read_graft_line(); it allows an empty line (both length-0 before the terminating LF or CRLF, and a line with isspace() only) and ignore them, so "grep '^[^#]'" is not sufficient. >> + /* make sure the commit is not corrupt */ >> + if (parse_commit_buffer(commit, buf.buf, buf.len)) >> + die(_("Could not parse commit: '%s'"), old_ref); > > I guess the checks here are sufficient to make... > >> + /* find existing parents */ >> + parent_start = buf.buf; >> + parent_start += 46; /* "tree " + "hex sha1" + "\n" */ >> + parent_end = parent_start; >> + >> + while (starts_with(parent_end, "parent ")) >> + parent_end += 48; /* "parent " + "hex sha1" + "\n" */ > > ...this number-based parsing safe, though it would miss removing a stray > parent line elsewhere in the commit. It still feels rather magical to > me, as we are depending on unspoken format guarantees defined inside > parse_commit_buffer. Do you mean "we have a carved-in-stone rule that all 'parent ' lines must come immediately after a single 'tree ' line, and that is implemented in parse_commit_buffer(). The above code follows the exact same rule. It would be nice to have some mechanism to tell somebody who wants to update the former that s/he must update this new code at the same time"? I think a commit object that violates the rule is simply broken, and it is OK to add a mode to tell parse-commit-buffer to tolerate such a broken object, if only so that filter-branch or some other tools can be used to correct a history that contains it. Perhaps a more future-proof way to write Christian's code may be: - find "tree "; - splice the new parents in immediately after that "tree " line; - starting from the end of these new parents, scan up to the end of the header line-by-line, and splice out any line that begins with "parent ". which may not be too bad. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html