From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
cc: tanghy.fnst@fujitsu.com, smithpb2250@gmail.com,
        peter.eisentraut@enterprisedb.com, david.zhang@highgo.ca,
        pgsql-hackers@lists.postgresql.org
Subject: Re: Support tab completion for upper character inputs in psql
In-reply-to: <20210423.115812.900808736988307020.horikyota.ntt@gmail.com>
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Comments: In-reply-to Kyotaro Horiguchi <horikyota.ntt@gmail.com>
	message dated "Fri, 23 Apr 2021 11:58:12 +0900"
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Date: Thu, 22 Apr 2021 23:17:19 -0400
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Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
> All usages of pg_string_tolower don't need a copy.
> So don't we change the function to in-place converter?

Doesn't seem like a good idea, because that locks us into an assumption
that the downcasing conversion doesn't change the string's physical
length.  There are a lot of counterexamples to that :-(.  I'm not sure
that we actually implement such cases correctly today, but let's not
build APIs that prevent it from being fixed.

			regards, tom lane