postgres.git / summary / log / commit / refs

commit    47bdd80dc119d793b7ce9f5d5e955d7ee7da2560
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Sat May 08 16:40:52 2010 +0000
First released in: 9.0.0, 7.4.29, 8.0.25, 8.1.21, 8.2.17, 8.3.11, 8.4.4

    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;
 }


[parent: 79c712aae837]