Apply post_group_filter in rehash on all groups

The filter was not applied on items matched by pre-filter
which in some cases led to incorrect reporting of unique files.

Fixes #148

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fclones"
-version = "0.27.0"
+version = "0.27.1"
 description = "Finds duplicate, unique, under- or over-replicated files"
 authors = ["Piotr Kołaczkowski <[email protected]>"]
 homepage = "https://github.com/pkolaczk/fclones"

src/config.rs

@@ -109,7 +109,7 @@ fn is_positive_int(v: String) -> Result<(), String> {
             return Ok(());
         }
     }
-    return Err(format!("Not a positive integer: {}", &*v));
+    Err(format!("Not a positive integer: {}", &*v))
 }
 
 #[derive(Clone, Copy, Debug)]

src/group.rs

@@ -606,8 +606,8 @@ where
             file_hash: hash,
             files: files.to_vec(),
         })
-        .filter(group_post_filter)
         .chain(groups_to_pass.into_iter())
+        .filter(group_post_filter)
         .collect()
 }
 
@@ -1790,6 +1790,28 @@ mod test {
         })
     }
 
+    #[test]
+    fn unique_files() {
+        with_dir("main/unique_files", |root| {
+            let file1 = root.join("file1");
+            let file2 = root.join("file2");
+            let file3 = root.join("file3");
+            write_test_file(&file1, b"duplicate", b"", b"");
+            write_test_file(&file2, b"duplicate", b"", b"");
+            write_test_file(&file3, b"unique", b"", b"");
+
+            let file3 = Path::from(file3);
+
+            let log = test_log();
+            let mut config = GroupConfig::default();
+            config.unique = true;
+            config.paths = vec![file1.into(), file2.into(), file3.clone()];
+            let results = group_files(&config, &log).unwrap();
+            assert_eq!(results.len(), 1);
+            assert_eq!(results[0].files[0].path, file3);
+        });
+    }
+
     #[test]
     fn report() {
         with_dir("main/report", |root| {