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, 3 insertions, 9 deletions

diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 124000fe7f4..3e2243958a6 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -2198,18 +2198,12 @@ text_name(PG_FUNCTION_ARGS)
 
 	/* Truncate oversize input */
 	if (len >= NAMEDATALEN)
-		len = NAMEDATALEN - 1;
+		len = pg_mbcliplen(VARDATA_ANY(s), len, NAMEDATALEN - 1);
 
-	result = (Name) palloc(NAMEDATALEN);
+	/* We use palloc0 here to ensure result is zero-padded */
+	result = (Name) palloc0(NAMEDATALEN);
 	memcpy(NameStr(*result), VARDATA_ANY(s), len);
 
-	/* now null pad to full length... */
-	while (len < NAMEDATALEN)
-	{
-		*(NameStr(*result) + len) = '\0';
-		len++;
-	}
-
 	PG_RETURN_NAME(result);
 }