From 1629881f4dab2ec6bd0a8e7ec1fd88d663108f54 Mon Sep 17 00:00:00 2001
From: Ville Vesilehto <ville@vesilehto.fi>
Date: Tue, 17 Feb 2026 20:25:30 +0200
Subject: [PATCH] fix: wrap LoadLocation error in date() builtin

When date() is called with an invalid timezone string like ".",
time.LoadLocation can return raw OS-level errors such as
"is a directory". Replace the raw error with a consistent
"unknown time zone" message to improve error clarity and match
the fuzz test's known-error skip patterns.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>
---
 builtin/builtin.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/builtin/builtin.go b/builtin/builtin.go
index 78b55be6..87e73614 100644
--- a/builtin/builtin.go
+++ b/builtin/builtin.go
@@ -530,7 +530,7 @@ var Builtins = []*Function{
 				timeZone := args[2].(string)
 				tz, err := time.LoadLocation(timeZone)
 				if err != nil {
-					return nil, err
+					return nil, fmt.Errorf("unknown time zone %s", timeZone)
 				}
 				t, err := time.ParseInLocation(layout, date, tz)
 				if err != nil {