From c37478ed843d043e0667f2b16f9a4d52c9a52286 Mon Sep 17 00:00:00 2001
From: mtkennerly <mtkennerly@gmail.com>
Date: Sun, 30 Jun 2024 08:39:45 -0400
Subject: [PATCH] Fix different ignored saves in consecutive differential
 backup

---
 CHANGELOG.md       |  4 ++++
 src/scan/layout.rs | 60 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cac3c34..e0401c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
 ## Unreleased
 
 * Fixed:
+  * If two consecutive differential backups both ignored *different* save files
+    *and* none of those files were ignored in the associated full backup,
+    then the second differential backup would fail to redeclare
+    the first differential backup's ignored saves.
   * GUI: On Mac, the file/folder selector would cause the app to crash.
 
 ## v0.24.2 (2024-06-28)
diff --git a/src/scan/layout.rs b/src/scan/layout.rs
index 3650ab1..8e23956 100644
--- a/src/scan/layout.rs
+++ b/src/scan/layout.rs
@@ -1010,7 +1010,7 @@ impl GameLayout {
                 ScanChange::New | ScanChange::Different | ScanChange::Same => {
                     files.insert(
                         file.mapping_key(),
-                        Some(IndividualMappingFile {
+                        (!file.ignored).then(|| IndividualMappingFile {
                             hash: file.hash.clone(),
                             size: file.size,
                         }),
@@ -2589,6 +2589,64 @@ mod tests {
             );
         }
 
+        #[test]
+        fn can_plan_second_differential_backup_with_different_ignored_files() {
+            let scan = ScanInfo {
+                found_files: hash_set! {
+                    // Ignored in first differential backup:
+                    ScannedFile::with_change(repo_file("file1"), 1, "1", ScanChange::New).ignored(),
+                    // Newly ignored:
+                    ScannedFile::with_change(repo_file("file2"), 2, "2", ScanChange::Same).ignored(),
+                    // Just here to keep the backup from being inert (all ignores):
+                    ScannedFile::with_change(repo_file("file3"), 3, "3", ScanChange::Same),
+                },
+                ..Default::default()
+            };
+            let layout = GameLayout {
+                mapping: IndividualMapping {
+                    drives: drives(),
+                    backups: VecDeque::from_iter(vec![FullBackup {
+                        name: ".".to_string(),
+                        when: past(),
+                        files: btree_map! {
+                            StrictPath::new(repo_file("file1")).render(): IndividualMappingFile { hash: "1".into(), size: 1 },
+                            StrictPath::new(repo_file("file2")).render(): IndividualMappingFile { hash: "2".into(), size: 2 },
+                            StrictPath::new(repo_file("file3")).render(): IndividualMappingFile { hash: "3".into(), size: 3 },
+                        },
+                        children: VecDeque::from([DifferentialBackup {
+                            name: format!("backup-{}-diff", now_str()),
+                            when: now(),
+                            os: Some(Os::HOST),
+                            files: btree_map! {
+                                StrictPath::new(repo_file("file1")).render(): None,
+                            },
+                            ..Default::default()
+                        }]),
+                        ..Default::default()
+                    }]),
+                    ..Default::default()
+                },
+                ..Default::default()
+            };
+            assert_eq!(
+                DifferentialBackup {
+                    name: format!("backup-{}-diff", now_str()),
+                    when: now(),
+                    os: Some(Os::HOST),
+                    files: btree_map! {
+                        // This matches the latest composite,
+                        // but we have to reiterate this in the new differential:
+                        StrictPath::new(repo_file("file1")).render(): None,
+                        // New ignore:
+                        StrictPath::new(repo_file("file2")).render(): None,
+                    },
+                    registry: None,
+                    ..Default::default()
+                },
+                layout.plan_differential_backup(&scan, &now(), &BackupFormats::default()),
+            );
+        }
+
         #[test]
         #[cfg(target_os = "windows")]
         fn can_plan_differential_backup_with_registry_new() {