Improve Polish spelling suggestions for final consonant devoicing (#1298)

Co-authored-by: neronek22 <aantoszek@gmail.com>

crates/proof/src/pl/suggest.rs

@@ -275,7 +275,10 @@ pub fn suggest_in(d: &AffixDict, word: &str, max: usize) -> Vec<String> {
                 if let Some(x) = v.get_mut(i) {
                     *x = c;
                 }
-                col.offer(&s(&v), COST_MISTYPE);
+                // Final devoicing can make a voiced consonant sound voiceless.
+                let final_devoicing = i == n - 1 && matches!((chars[i], c), ('p', 'b') | ('t', 'd') | ('k', 'g'));
+                let cost = if final_devoicing { COST_ADD_DIACRITIC - 1 } else { COST_MISTYPE };
+                col.offer(&s(&v), cost);
             }
         }
     }
@@ -389,6 +392,13 @@ mod tests {
         has("dziewczyan", "dziewczyna");
     }
 
+    #[test]
+    fn voiced_consonant_suggestion_ranks_first() {
+        crate::pl::test_dict::install();
+        let result = suggest("chlep", 6);
+        assert_eq!(result.first().map(String::as_str), Some("chleb"), "{result:?}");
+    }
+
     #[test]
     fn the_likeliest_fix_comes_first() {
         crate::pl::test_dict::install();

crates/proof/src/pl/test_dict.rs

@@ -33,10 +33,16 @@ PFX N 0 nie .
 ";
 
 /// Stems (the count line first, as in Hunspell files).
-pub const DIC: &str = "63
+pub const DIC: &str = "69
 źdźbło
 gżegżółka
 chrząszcz
+chleb
+chłep
+chlap
+chlip
+chlup
+chlej
 pięćdziesięciu
 rzeka
 którzy