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Work around a subtle portability problem in use of printf %s format.

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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".
This commit is contained in:
Tom Lane 2010-05-08 16:40:03 +00:00
parent aa4a0e6fc3
commit 191c52a27b
4 changed files with 65 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/backend/parser/scansup.c
View File

@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/scansup.c,v 1.37 2009/01/01 17:23:46 momjian Exp $
* $PostgreSQL: pgsql/src/backend/parser/scansup.c,v 1.37.2.1 2010/05/08 16:40:03 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';
}
}

6
src/backend/utils/error/elog.c
View File

@ -42,7 +42,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.216 2009/06/25 23:07:15 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/error/elog.c,v 1.216.2.1 2010/05/08 16:40:03 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1782,7 +1782,7 @@ log_line_prefix(StringInfo buf)
int displen;
psdisp = get_ps_display(&displen);
appendStringInfo(buf, "%.*s", displen, psdisp);
appendBinaryStringInfo(buf, psdisp, displen);
}
break;
case 'r':
@ -1937,7 +1937,7 @@ write_csvlog(ErrorData *edata)
initStringInfo(&msgbuf);
psdisp = get_ps_display(&displen);
appendStringInfo(&msgbuf, "%.*s", displen, psdisp);
appendBinaryStringInfo(&msgbuf, psdisp, displen);
appendCSVLiteral(&buf, msgbuf.data);
pfree(msgbuf.data);

29
src/bin/psql/print.c
View File

@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2009, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/bin/psql/print.c,v 1.116.2.3 2010/03/01 21:27:32 heikki Exp $
* $PostgreSQL: pgsql/src/bin/psql/print.c,v 1.116.2.4 2010/05/08 16:40:03 tgl Exp $
*/
#include "postgres_fe.h"
@ -172,6 +172,20 @@ format_numeric_locale(const char *my_str)
return new_str;
}
/*
* 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);
}
/*************************/
/* Unaligned text */
/*************************/
@ -813,14 +827,16 @@ print_aligned_text(const printTableContent *cont, FILE *fout)
{
/* spaces first */
fprintf(fout, "%*s", width_wrap[j] - chars_to_output, "");
fprintf(fout, "%.*s", bytes_to_output,
this_line->ptr + bytes_output[j]);
fputnbytes(fout,
this_line->ptr + bytes_output[j],
bytes_to_output);
}
else /* Left aligned cell */
{
/* spaces second */
fprintf(fout, "%.*s", bytes_to_output,
this_line->ptr + bytes_output[j]);
fputnbytes(fout,
this_line->ptr + bytes_output[j],
bytes_to_output);
if (finalspaces)
fprintf(fout, "%*s", width_wrap[j] - chars_to_output, "");
}
@ -1030,7 +1046,10 @@ print_aligned_vertical(const printTableContent *cont, FILE *fout)
record_str_len = strlen(record_str);
if (record_str_len + opt_border > strlen(divider))
{
/* %.*s OK here because divider is all ASCII */
fprintf(fout, "%.*s%s\n", opt_border, divider, record_str);
}
else
{
char *div_copy = pg_strdup(divider);

29
src/interfaces/libpq/fe-misc.c
View File

@ -23,7 +23,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-misc.c,v 1.140 2009/06/11 14:49:14 momjian Exp $
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-misc.c,v 1.140.2.1 2010/05/08 16:40:03 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -67,6 +67,20 @@ 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
*
@ -187,8 +201,11 @@ 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;
}
@ -204,7 +221,11 @@ 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;
}