Update changelog

CHANGELOG.md

@@ -1,5 +1,11 @@
 # SpamAssassin Milter changelog
 
+## 0.1.6 (unreleased)
+
+*   Improve processing of incoming `X-Spam-Flag` headers. Previously, in rare
+    circumstances a message flagged as spam would not be rejected as requested.
+    Reported by Petar Bogdanovic.
+
 ## 0.1.5 (2021-03-16)
 
 *   Read output from `spamc` in a separate thread in order to avoid blocking

src/email.rs

@@ -145,7 +145,7 @@ pub static REPORT_HEADERS: Lazy<HeaderSet<'static>> = Lazy::new(|| {
 pub struct HeaderRewriter<'a> {
     original: HeaderMap,
     processed: HeaderSet<'a>,
-    spam: Option<bool>,
+    spam_flag: Option<bool>,
     spam_assassin_mods: Vec<HeaderMod<'a>>,
     rewrite_mods: Vec<HeaderMod<'a>>,
     report_mods: Vec<HeaderMod<'a>>,
@@ -157,7 +157,7 @@ impl<'a> HeaderRewriter<'a> {
         Self {
             original,
             processed: HeaderSet::new(),
-            spam: None,
+            spam_flag: None,
             spam_assassin_mods: vec![],
             rewrite_mods: vec![],
             report_mods: vec![],
@@ -169,7 +169,7 @@ impl<'a> HeaderRewriter<'a> {
         // Assumes that the value is normalised to using CRLF line breaks, and
         // includes leading whitespace.
         if name.eq_ignore_ascii_case("X-Spam-Flag") {
-            self.spam.get_or_insert_with(|| value.trim().eq_ignore_ascii_case("YES"));
+            self.spam_flag.get_or_insert_with(|| value.trim().eq_ignore_ascii_case("YES"));
         }
         if is_spam_assassin_header(name) {
             if let Some(m) = self.convert_to_header_mod(name, value) {
@@ -204,7 +204,7 @@ impl<'a> HeaderRewriter<'a> {
     }
 
     pub fn is_flagged_spam(&self) -> bool {
-        self.spam == Some(true)
+        self.spam_flag.unwrap_or(false)
     }
 
     pub fn rewrite_spam_assassin_headers(