From 47bdd80dc119d793b7ce9f5d5e955d7ee7da2560 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 8 May 2010 16:40:52 +0000 Subject: [PATCH] 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". --- src/backend/parser/scansup.c | 16 +++++++++++++--- src/interfaces/libpq/fe-misc.c | 28 +++++++++++++++++++++++++--- 2 files changed, 38 insertions(+), 6 deletions(-) diff --git a/src/backend/parser/scansup.c b/src/backend/parser/scansup.c index 14467dcdc77..254e3d7d763 100644 --- a/src/backend/parser/scansup.c +++ b/src/backend/parser/scansup.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/scansup.c,v 1.24.4.1 2004/02/21 00:35:13 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/scansup.c,v 1.24.4.2 2010/05/08 16:40:52 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -176,10 +176,20 @@ truncate_identifier(char *ident, int len, bool warn) { len = pg_mbcliplen(ident, len, NAMEDATALEN-1); if (warn) + { + /* + * Cannot use %.*s here because some machines interpret %s's + * precision in characters, others in bytes. + */ + char buf[NAMEDATALEN]; + + memcpy(buf, ident, len); + buf[len] = '\0'; ereport(NOTICE, (errcode(ERRCODE_NAME_TOO_LONG), - errmsg("identifier \"%s\" will be truncated to \"%.*s\"", - ident, len, ident))); + errmsg("identifier \"%s\" will be truncated to \"%s\"", + ident, buf))); + } ident[len] = '\0'; } } diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c index 0f3f2813711..c16c8d3330a 100644 --- a/src/interfaces/libpq/fe-misc.c +++ b/src/interfaces/libpq/fe-misc.c @@ -23,7 +23,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.103.2.1 2005/07/08 15:25:19 tgl Exp $ + * $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.103.2.2 2010/05/08 16:40:52 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -69,6 +69,20 @@ static int pqSocketCheck(PGconn *conn, int forRead, int forWrite, static int pqSocketPoll(int sock, int forRead, int forWrite, time_t end_time); +/* + * fputnbytes: print exactly N bytes to a file + * + * Think not to use fprintf with a %.*s format for this. Some machines + * believe %s's precision is measured in characters, others in bytes. + */ +static void +fputnbytes(FILE *f, const char *str, size_t n) +{ + while (n-- > 0) + fputc(*str++, f); +} + + /* * pqGetc: get 1 character from the connection * @@ -175,7 +189,11 @@ pqGetnchar(char *s, size_t len, PGconn *conn) conn->inCursor += len; if (conn->Pfdebug) - fprintf(conn->Pfdebug, "From backend (%lu)> %.*s\n", (unsigned long) len, (int) len, s); + { + fprintf(conn->Pfdebug, "From backend (%lu)> ", (unsigned long) len); + fputnbytes(conn->Pfdebug, s, len); + fprintf(conn->Pfdebug, "\n"); + } return 0; } @@ -191,7 +209,11 @@ pqPutnchar(const char *s, size_t len, PGconn *conn) return EOF; if (conn->Pfdebug) - fprintf(conn->Pfdebug, "To backend> %.*s\n", (int) len, s); + { + fprintf(conn->Pfdebug, "To backend> "); + fputnbytes(conn->Pfdebug, s, len); + fprintf(conn->Pfdebug, "\n"); + } return 0; } -- 2.39.5