Re: [PATCH] Don't truncate integer part in to_char for 'FM99.'

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Marti Raudsepp <marti@juffo.org>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-09-07T18:37:27Z
Lists: pgsql-hackers
Marti Raudsepp <marti@juffo.org> writes:
> This patch fixes an edge case bug in the numeric to_char() function.

> When the numeric to_char format used fillmode (FM), didn't contain 0s
> and had a trailing dot, the integer part of the number was truncated in
> error.

> to_char(10, 'FM99.') used to return '1', after this patch it will return '10'


Hmm.  I agree that this is a bug, but the proposed fix seems like a bit
of a kluge.  Wouldn't it be better to make get_last_relevant_decnum
honor its contract, that is not delete any relevant digits?  I'm
thinking instead of this

	if (!p)
		p = num;

when there is no decimal point it should do something like

	if (!p)
		return num + strlen(num) - 1;

			regards, tom lane