From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jonathan Nieder <jrnieder@gmail.com>
Subject: Re: [PATCHv4 05/21] notes.h/c: Clarify the handling of notes objects
 that are == null_sha1
Date: Thu, 21 Oct 2010 12:54:05 -0500
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References: <1287626936-32232-1-git-send-email-johan@herland.net>
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 <20101021051232.GA2413@burratino>
 <201010211513.06176.johan@herland.net>
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To: Johan Herland <johan@herland.net>
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Johan Herland wrote:

>   Allow combine_notes functions to request that a note be removed,
>   by setting the resulting note SHA1 to null_sha1 (0000000...).
> 
>   For consistency, also teach note_tree_insert() to skip insertion
>   of an empty note when there is no note to combine it with.

I guess it's probably also worth clarifying that the term "empty note"
means null_sha1 rather than empty_blob_sha1.

i.e. something like:

	For consistency, also teach note_tree_insert() to skip insertion
	of an empty note (a note with val_sha1 equal to null_sha1)
	when there is no note to combine it with.

The previous behavior iiuc would have been for write_notes_tree() to
write invalid trees after such an operation.