From f0a264a362343287051c4737b01aa3ebe36f21a6 Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Sat, 20 Jun 2015 12:09:29 -0400
Subject: [PATCH] Fix failure to copy setlocale() return value.
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POSIX permits setlocale() calls to invalidate any previous setlocale()
return values, but commit 5f538ad004aa00cf0881f179f0cde789aad4f47e
neglected to account for setlocale(LC_CTYPE, NULL) doing so. The effect
was to set the LC_CTYPE environment variable to an unintended value.
pg_perm_setlocale() sets this variable to assist PL/Perl; without it,
Perl would undo PostgreSQL's locale settings. The known-affected
configurations are 32-bit, release builds using Visual Studio 2012 or
Visual Studio 2013. Visual Studio 2010 is unaffected, as were all
buildfarm-attested configurations. In principle, this bug could leave
the wrong LC_CTYPE in effect after PL/Perl use, which could in turn
facilitate problems like corrupt tsvector datums. No known platform
experiences that consequence, because PL/Perl on Windows does not use
this environment variable.
The bug has been user-visible, as early postmaster failure, on systems
with Windows ANSI code page set to CP936 for "Chinese (Simplified, PRC)"
and probably on systems using other multibyte code pages.
(SetEnvironmentVariable() rejects values containing character data not
valid under the Windows ANSI code page.) Back-patch to 9.4, where the
faulty commit first appeared.
Reported by Didi Hu and æž—é¹ç¨‹. Reviewed by Tom Lane, though this fix
strategy was not his first choice.
---
src/backend/utils/adt/pg_locale.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 4be735e918d..84215e07a77 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -183,6 +183,12 @@ pg_perm_setlocale(int category, const char *locale)
*/
if (category == LC_CTYPE)
{
+ static char save_lc_ctype[LC_ENV_BUFSIZE];
+
+ /* copy setlocale() return value before callee invokes it again */
+ strlcpy(save_lc_ctype, result, sizeof(save_lc_ctype));
+ result = save_lc_ctype;
+
#ifdef ENABLE_NLS
SetMessageEncoding(pg_bind_textdomain_codeset(textdomain(NULL)));
#else
--
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