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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".
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

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';
}
}

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);