Reject %y in strftime for year < 1900 on Windows

youknowone · youknowone · commit 10220a85c703 · 2026-02-13T18:12:24.000+09:00
diff --git a/crates/vm/src/stdlib/time.rs b/crates/vm/src/stdlib/time.rs
@@ -631,6 +631,22 @@ mod decl {
             if !(1..=9999).contains(&year) {
                 return Err(vm.new_value_error("strftime() requires year in [1; 9999]".to_owned()));
             }
+            // %y requires year >= 1900 on Windows
+            if tm.tm_year < 0 {
+                let fmt = format.as_str();
+                let mut chars = fmt.chars();
+                while let Some(ch) = chars.next() {
+                    if ch == '%' {
+                        if let Some(next) = chars.next() {
+                            if next == 'y' {
+                                return Err(vm.new_value_error(
+                                    "format %y requires year >= 1900 on Windows".to_owned(),
+                                ));
+                            }
+                        }
+                    }
+                }
+            }
         }
 
         #[cfg(unix)]
