Fix more format truncation issues

Fix the warnings created by the compiler warning options
-Wformat-overflow=2 -Wformat-truncation=2, supported since GCC 7.  This
is a more aggressive variant of the fixes in
6275f5d28a1577563f53f2171689d4f890a46881, which GCC 7 warned about by
default.

The issues are all harmless, but some dubious coding patterns are
cleaned up.

One issue that is of external interest is that BGW_MAXLEN is increased
from 64 to 96.  Apparently, the old value would cause the bgw_name of
logical replication workers to be truncated in some circumstances.

But this doesn't actually add those warning options.  It appears that
the warnings depend a bit on compilation and optimization options, so it
would be annoying to have to keep up with that.  This is more of a
once-in-a-while cleanup.

Reviewed-by: Michael Paquier <michael@paquier.xyz>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index fc3e10c7509..4116c2d66ac 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10528,7 +10528,7 @@ check_cluster_name(char **newval, void **extra, GucSource source)
 static const char *
 show_unix_socket_permissions(void)
 {
-	static char buf[8];
+	static char buf[12];
 
 	snprintf(buf, sizeof(buf), "%04o", Unix_socket_permissions);
 	return buf;
@@ -10537,7 +10537,7 @@ show_unix_socket_permissions(void)
 static const char *
 show_log_file_mode(void)
 {
-	static char buf[8];
+	static char buf[12];
 
 	snprintf(buf, sizeof(buf), "%04o", Log_file_mode);
 	return buf;