From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
cc: Andrew Dunstan <andrew@dunslane.net>,
        pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Prevent infinity and NaN in jsonb/plperl transform
In-reply-to: <59e5787f-314e-6e5d-db5e-bcb6b9dbc25c@2ndquadrant.com>
References: <E1fDCX9-0005yu-7q@gemulon.postgresql.org>
 <21194.1525110966@sss.pgh.pa.us>
 <59e5787f-314e-6e5d-db5e-bcb6b9dbc25c@2ndquadrant.com>
Comments: In-reply-to Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
	message dated "Mon, 30 Apr 2018 14:36:45 -0400"
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Date: Mon, 30 Apr 2018 14:41:58 -0400
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Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> On 4/30/18 13:56, Tom Lane wrote:
>> So this isn't working on Windows: ...
>> The reason seems to be this kluge in plperl.h:
>> 
>> /* stop perl headers from hijacking stdio and other stuff on Windows */
>> #ifdef WIN32
>> #define WIN32IO_IS_STDIO
>> /*
>> * isnan is defined in both the perl and mingw headers. We don't use it,
>> * so this just clears up the compile warning.
>> */
>> #ifdef isnan
>> #undef isnan
>> #endif
>> #endif							/* WIN32 */
>> 
>> Looks like the half-life of that hack just expired.  What shall
>> we do about it?

> I have removed this for now.  If it's really just about a compiler
> warning, then we can find a different workaround later.

I was just about to propose exactly that fix.  This undef'ing of isnan
traces back to Andrew's 2006 commit ea73a78b0.  I think perhaps that's not
necessary with any still-supported version of Perl; I see no evidence on
my machines that any Perl header #defines isnan.  There is this bit:

#ifdef UNDER_CE
int isnan(double d);
#endif

which would cause trouble if isnan is a macro, but we can hope that
that doesn't apply to us.

			regards, tom lane