Re: [PATCH 2/2] Add keyword unexpansion support to convert.c
- From
Robin H. Johnson <robbat2@gentoo.org>
- Date
- Apr 18, 2007, 02:53 UTC
- Message-ID
- <20070418025338.GG31488@curie-int.orbis-terrarum.net>
- In-Reply-To
- <7vy7kqjw4x.fsf@assigned-by-dhcp.cox.net>
On Tue, Apr 17, 2007 at 06:42:38PM -0700, Junio C Hamano wrote:
Show 7 quoted lines
> Junio C Hamano <junkio@cox.net> writes: > > I do not have much against an optional "only blob id" expansion > > myself, as I do not see any more downside than CRLF expansion in > > it... > Actually, there is one. Somebody makes a patch against a file > with $id$ expanded. Gives it to somebody else who is git > challenged and does not have git-apply. The patch is useless.
So they have diff'd outside of Git, and the recipient is applying outside of
Git:
A - If they are applying the patch on top of the same base revision, it will
apply fine, because the keywords are identical.
B - If they are applying the patch on top of a different revision, the keywords
won't apply, and most probably other content in the patch won't apply either.Additional with B the longer your individual files, the more likely that the diff hunk containing the keyword change does not contain any other changes, and can be easily discarded. More that the changes are likely to be further away from the keyword ;-).
Discarding portions of patches is already wide-spread (not just for CVS keywords, the architecture keywords in Gentoo ebuilds change rapidly as well), and if git-apply can discard the keyword, it only serves to accelerate the usage of git.
Some quick stats I hacked together on lengths of Gentoo ebuilds. 23161 ebuilds total. 51% of the Gentoo ebuilds are less than 36 lines long. 76% are less than 56 lines long. 90% are less than 92 lines long. (thereafter the tail gets VERY long). 0.21% are more than 500 lines long.
> So it is not without more downsides than CRLF.
A cleaner version of my earlier command to find the changes between revisions. diff -Nuar <(git-cat-file blob $SHA1:$FILE) $TMPFILE where $TMPFILE is a temporary filename for the file from the user. This saves having to overwrite the local $FILE and restore it afterwards. It would be nice if git-diff could handle this case directly.
On a tangent, has any work gone into specialized patch mergers for specific file formats?
-- Robin Hugh Johnson Gentoo Linux Developer & Council Member E-Mail : robbat2@gentoo.org GnuPG FP : 11AC BA4F 4778 E3F6 E4ED F38E B27B 944E 3488 4E85