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".

1 files changed, 8 insertions, 1 deletions

diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 4a94a1ace12..b9624451c35 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2010, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.218 2010/04/03 20:55:57 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/command.c,v 1.219 2010/05/08 16:39:51 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "command.h"
@@ -651,6 +651,13 @@ exec_command(const char *cmd,
 	{
 		char	   *opt = psql_scan_slash_option(scan_state,
 												 OT_WHOLE_LINE, NULL, false);
+		size_t		len;
+
+		/* strip any trailing spaces and semicolons */
+		len = strlen(opt);
+		while (len > 0 &&
+			   (isspace((unsigned char) opt[len - 1]) || opt[len - 1] == ';'))
+			opt[--len] = '\0';
 
 		helpSQL(opt, pset.popt.topt.pager);
 		free(opt);