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From: Junio C Hamano <gitster@pobox.com>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: Jeff King <peff@peff.net>, Johan Herland <johan@herland.net>,
	Thomas Rast <trast@inf.ethz.ch>,
	git@vger.kernel.org
Subject: Re: [PATCH v2 11/25] object_array_remove_duplicates(): rewrite to reduce copying
Date: Sun, 02 Jun 2013 14:02:41 -0700	[thread overview]
Message-ID: <7vy5asmdji.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <51A7C146.6090605@alum.mit.edu> (Michael Haggerty's message of "Thu, 30 May 2013 23:14:46 +0200")

Michael Haggerty <mhagger@alum.mit.edu> writes:

>> The only caller of remove-duplicates is bundle.c, which gets many
>> starting points and end points from the command line and tries to be
>> nice by removing obvious duplicates, e.g.
>> 
>> 	git bundle create t.bundle master master
>> 
>> but I think its logic of deduping is wrong.  It runs dwim_ref() on
>> the incoming refs after the remove-duplicates call, so
>> 
>> 	git bundle create t.bundle master heads/mater
>> 
>> will end up with two copies of refs/heads/master.  To fix it, the
>> code must dedup the result of running dwim_ref(), and at that point,
>> there is no reason to call object_array_remove_duplicates().
>
> That sounds reasonable.
>
> I poked around this code a bit to understand what is going on, and it
> occurred to me that the object_array can include both positive and
> negative references, right?  And yet object_array_remove_duplicates()
> only considers names, not flags.  So it seems to me that if the deduping
> code would see the same reference twice, once positive and once
> negative, then it would throw an arbitrary one of them out, which would
> be wrong.
>
> But I couldn't provoke this situation, so perhaps setup_revisions()
> already specially treats combinations like "master ^master"?  (If that's
> true then why? and wouldn't it get confused by "master ^heads/master"?)

With "git bundle create t.bundle ^master master", you see two
entries in revs.pending.objects[] but they are the same object and
is already marked as uninteresting, so you will not see 'master' in
the result.

This parsing loop predates the more recent revs->cmdline mechanism,
that treats these two command line arguments as separate entities,
so that we can more reliably tell what the real end-user input is.

  reply	other threads:[~2013-06-02 21:03 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-25  9:07 [PATCH v2 00/25] Remove assumptions about each_ref_fn arg lifetimes Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 01/25] describe: make own copy of refname Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 02/25] fetch: make own copies of refnames Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 03/25] add_rev_cmdline(): make a copy of the name argument Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 04/25] builtin_diff_tree(): make it obvious that function wants two entries Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 05/25] cmd_diff(): use an object_array for holding trees Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 06/25] cmd_diff(): rename local variable "list" -> "entry" Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 07/25] cmd_diff(): make it obvious which cases are exclusive of each other Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 08/25] revision: split some overly-long lines Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 09/25] object_array: add function object_array_filter() Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 10/25] revision: use object_array_filter() in implementation of gc_boundary() Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 11/25] object_array_remove_duplicates(): rewrite to reduce copying Michael Haggerty
2013-05-29 16:18   ` Junio C Hamano
2013-05-30 21:14     ` Michael Haggerty
2013-06-02 21:02       ` Junio C Hamano [this message]
2013-05-25  9:08 ` [PATCH v2 12/25] fsck: don't put a void*-shaped peg in a char*-shaped hole Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 13/25] find_first_merges(): initialize merges variable using initializer Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 14/25] find_first_merges(): remove unnecessary code Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 15/25] object_array_entry: fix memory handling of the name field Michael Haggerty
2013-05-29 16:24   ` Junio C Hamano
2013-05-25  9:08 ` [PATCH v2 16/25] do_fetch(): reduce scope of peer_item Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 17/25] do_fetch(): clean up existing_refs before exiting Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 18/25] add_existing(): do not retain a reference to sha1 Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 19/25] show_head_ref(): do not shadow name of argument Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 20/25] show_head_ref(): rename first parameter to "refname" Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 21/25] string_list_add_one_ref(): " Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 22/25] string_list_add_refs_by_glob(): add a comment about memory management Michael Haggerty
2013-05-29  8:21   ` Thomas Rast
2013-05-30 19:29     ` Michael Haggerty
2013-05-30 22:05     ` [PATCH v2 FIXUP 22/25] fixup! " Michael Haggerty
2013-06-03 15:31       ` Junio C Hamano
2013-05-25  9:08 ` [PATCH v2 23/25] exclude_existing(): set existing_refs.strdup_strings Michael Haggerty
2013-05-25  9:08 ` [PATCH v2 24/25] register_ref(): make a copy of the bad reference SHA-1 Michael Haggerty
2013-05-29 16:53   ` Junio C Hamano
2013-05-30 21:51     ` Michael Haggerty
2013-05-30 22:09       ` Philip Oakley
2013-05-25  9:08 ` [PATCH v2 25/25] refs: document the lifetime of the args passed to each_ref_fn Michael Haggerty
2013-05-29 16:54   ` Junio C Hamano
2013-05-29  8:25 ` [PATCH v2 00/25] Remove assumptions about each_ref_fn arg lifetimes Thomas Rast
2013-05-30 19:55   ` Michael Haggerty

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