Skip site navigation (1) Skip section navigation (2)

pgsql: Work around a subtle portability problem in use of printf %s

From: tgl(at)postgresql(dot)org (Tom Lane)
To: pgsql-committers(at)postgresql(dot)org
Subject: pgsql: Work around a subtle portability problem in use of printf %s
Date: 2010-05-08 16:40:14
Message-ID: 20100508164014.BFD417541D3@cvs.postgresql.org (view raw or flat)
Thread:
Lists: pgsql-committers
Log Message:
-----------
Work around a subtle portability problem in use of printf %s format.
Depending on which spec you read, field widths and precisions in %s may be
counted either in bytes or characters.  Our code was assuming bytes, which
is wrong at least for glibc's implementation, and in any case libc might
have a different idea of the prevailing encoding than we do.  Hence, for
portable results we must avoid using anything more complex than just "%s"
unless the string to be printed is known to be all-ASCII.

This patch fixes the cases I could find, including the psql formatting
failure reported by Hernan Gonzalez.  In HEAD only, I also added comments
to some places where it appears safe to continue using "%.*s".

Tags:
----
REL8_3_STABLE

Modified Files:
--------------
    pgsql/src/backend/parser:
        scansup.c (r1.36 -> r1.36.2.1)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/scansup.c?r1=1.36&r2=1.36.2.1)
    pgsql/src/backend/utils/error:
        elog.c (r1.201.2.4 -> r1.201.2.5)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/error/elog.c?r1=1.201.2.4&r2=1.201.2.5)
    pgsql/src/interfaces/libpq:
        fe-misc.c (r1.133.2.1 -> r1.133.2.2)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-misc.c?r1=1.133.2.1&r2=1.133.2.2)

pgsql-committers by date

Next:From: Tom LaneDate: 2010-05-08 16:40:31
Subject: pgsql: Work around a subtle portability problem in use of printf %s
Previous:From: Tom LaneDate: 2010-05-08 16:40:03
Subject: pgsql: Work around a subtle portability problem in use of printf %s

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group