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

@@ -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\"",
+					 errmsg("identifier \"%s\" will be truncated to \"%s\"",
-							ident, len, ident)));
+							ident, buf)));
+		}
 		ident[len] = '\0';
 	}
 }

src/backend/utils/error/elog.c

@@ -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);

src/bin/psql/print.c

@@ -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,
+						fputnbytes(fout,
-								this_line->ptr + bytes_output[j]);
+								   this_line->ptr + bytes_output[j],
+								   bytes_to_output);
 					}
 					else	/* Left aligned cell */
 					{
 						/* spaces second */
-						fprintf(fout, "%.*s", bytes_to_output,
+						fputnbytes(fout,
-								this_line->ptr + bytes_output[j]);
+								   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);

src/interfaces/libpq/fe-misc.c

@@ -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;
 }