From: Junio C Hamano <gitster@pobox•com>
To: git@vger•kernel.org
Subject: Re: [RFH] "diff -B -M"
Date: Fri, 06 Feb 2015 14:47:24 -0800 [thread overview]
Message-ID: <xmqqegq2d5dv.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <xmqqvbjed76s.fsf@gitster.dls.corp.google.com> (Junio C. Hamano's message of "Fri, 06 Feb 2015 14:08:27 -0800")
Junio C Hamano <gitster@pobox•com> writes:
> 5. Third twist: rewriting by copying
> ...
> One possible way to fix this is to include another patch in the same
> patchset that shows the deletion of major-11.txt. The rule 2. would
> be further revised to something like:
>
> rule 2. a patch renaming file A to file B requires that file A
> exists and file B does not exist in the target tree, unless
> another patch in the patchset renames file B to some other
> file (possibly but not necessarily file A) or removed file
Typofix: s/removed/removes/
> B, in which case file B must appear in the target tree.
>
> Such a patchset would look like this:
>
> diff --git a/major-08.txt b/major-11.txt
> similarity index 97%
> rename from major-08.txt
> rename to major-11.txt
> ...
> diff --git a/major-11.txt b/major-11.txt
> deleted file mode 100644
> ...
>
> And these patches, under the re-revised rule 2. and rule 4., would
> apply cleanly to the old tree.
>
> What about the reverse application? It would be a patchset that
> creates major-11.txt from nothingness, and creates major-08.txt by
> renaming major-11.txt and editing. Is the rule 2. re-revised above
> sufficient?
>
> renaming major-11.txt to major-08.txt requires that major-08.txt
> does not exist in the target tree, unless...
>
> and the new tree (which is the target of the reverse application)
> only has major-11.txt and not major-08.txt, so this rename should go
> through. The reverse of the deletion of major-11.txt is a creation
> of it with the contents fully given as the pre-image of the
> (original) patch before reversing it, so that should also be OK with
> rule 3.
... But rule 3. needs tweaking. The second patch would be creating
major-11.txt which requires major-11.txt to be missing in the target
tree. But obviously, the new tree the patch we are applying in
reverse was taken from has major-11.txt. So we would need a
revision to it as well.
rule 3. a patch that creates file A requires that file A does not exist
in the target tree, unless another patch in the same patchset
renames file A away or removes it.
> So tentatively, I would say...
>
> Action item: do not filter delete-half of the broken pair
> out, even when the other create-half of the pair no longer
> is in the output.
>
> Action item: update "git apply" to honor the rule 2.
> re-revised above.
The latter should read:
update "git apply" to honor the revised rule 2. and 3.
next prev parent reply other threads:[~2015-02-06 22:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-06 22:08 [RFH] "diff -B -M" Junio C Hamano
2015-02-06 22:47 ` Junio C Hamano [this message]
2015-02-06 23:06 ` [PATCH] apply: do not allow reversing a 'copy' patch Junio C Hamano
2015-02-06 23:39 ` Stefan Beller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqegq2d5dv.fsf@gitster.dls.corp.google.com \
--to=gitster@pobox$(echo .)com \
--cc=git@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox