Fix string truncation to be multibyte-aware in text_name and bpchar_name.

Previously, casts to name could generate invalidly-encoded results.

Also, make these functions match namein() more exactly, by consistently
using palloc0() instead of ad-hoc zeroing code.

Back-patch to all supported branches.

Karl Schnaitter and Tom Lane

1 files changed, 7 insertions, 3 deletions

diff --git a/src/backend/utils/adt/name.c b/src/backend/utils/adt/name.c
index 736e26ddb42..b3273b89427 100644
--- a/src/backend/utils/adt/name.c
+++ b/src/backend/utils/adt/name.c
@@ -46,13 +46,17 @@ Datum
 namein(PG_FUNCTION_ARGS)
 {
 	char	   *s = PG_GETARG_CSTRING(0);
-	NameData   *result;
+	Name		result;
 	int			len;
 
 	len = strlen(s);
-	len = pg_mbcliplen(s, len, NAMEDATALEN - 1);
 
-	result = (NameData *) palloc0(NAMEDATALEN);
+	/* Truncate oversize input */
+	if (len >= NAMEDATALEN)
+		len = pg_mbcliplen(s, len, NAMEDATALEN - 1);
+
+	/* We use palloc0 here to ensure result is zero-padded */
+	result = (Name) palloc0(NAMEDATALEN);
 	memcpy(NameStr(*result), s, len);
 
 	PG_RETURN_NAME(result);