compare letters before suffixes, and having a letter is greater than none

src/atom/mod.rs

@@ -407,12 +407,6 @@ impl Ord for Version {
             Ordering::Equal => (),
         }
 
-        match self.suffixes.cmp(&other.suffixes) {
-            Ordering::Less => return Ordering::Less,
-            Ordering::Greater => return Ordering::Greater,
-            Ordering::Equal => (),
-        }
-
         match (self.letter, other.letter) {
             (Some(a), Some(b)) if a < b => return Ordering::Less,
             (Some(a), Some(b)) if a > b => return Ordering::Greater,
@@ -423,6 +417,12 @@ impl Ord for Version {
             _ => unreachable!(),
         }
 
+        match self.suffixes.cmp(&other.suffixes) {
+            Ordering::Less => return Ordering::Less,
+            Ordering::Greater => return Ordering::Greater,
+            Ordering::Equal => (),
+        }
+
         match (&self.rev, &other.rev) {
             (Some(a), Some(b)) => match a
                 .get()
@@ -866,4 +866,19 @@ mod test {
 
         assert_cmp_display!(a, b, Ordering::Greater);
     }
+
+    #[test]
+    fn test_fuzzer_cases() {
+        let control = Version::parser()
+            .parse_finished(InputIter::new("1.2.0a_alpha1_beta2-r1-8"))
+            .unwrap();
+
+        for (version_str, expected) in [("1.2.0", Ordering::Greater)] {
+            let version = Version::parser()
+                .parse_finished(InputIter::new(version_str))
+                .unwrap();
+
+            assert_cmp_display!(control, version, expected);
+        }
+    }
 }