From e46c8ab9eebb06f07c397037936f7c11ded84484 Mon Sep 17 00:00:00 2001
From: Simon Frei <freisim93@gmail.com>
Date: Thu, 30 Jul 2020 13:41:45 +0200
Subject: [PATCH] lib/model: Detect deleted RO items scanning on non-RO (fixes
 #6864) (#6865)

---
 lib/model/folder.go     | 31 +++++++++++++++++--------------
 lib/model/model_test.go | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 14 deletions(-)

diff --git a/lib/model/folder.go b/lib/model/folder.go
index 808b7d7d4..6e55bba20 100644
--- a/lib/model/folder.go
+++ b/lib/model/folder.go
@@ -557,6 +557,8 @@ func (f *folder) scanSubdirs(subDirs []string) error {
 			}
 
 			switch ignored := f.ignores.Match(file.Name).IsIgnored(); {
+			case file.IsIgnored() && ignored:
+				return true
 			case !file.IsIgnored() && ignored:
 				// File was not ignored at last pass but has been ignored.
 				if file.IsDirectory() {
@@ -600,24 +602,25 @@ func (f *folder) scanSubdirs(subDirs []string) error {
 					// sure the file gets in sync on the following pull.
 					nf.Version = protocol.Vector{}
 				}
-
+				// Check for deleted, locally changed items that noone else has.
+				if f.localFlags&protocol.FlagLocalReceiveOnly != 0 && len(snap.Availability(file.Name)) == 0 {
+					file.LocalFlags &^= protocol.FlagLocalReceiveOnly
+				}
 				batchAppend(nf, snap)
 				changes++
+			case file.IsDeleted() && file.IsReceiveOnlyChanged() && f.localFlags&protocol.FlagLocalReceiveOnly != 0 && len(snap.Availability(file.Name)) == 0:
+				file.Version = protocol.Vector{}
+				file.LocalFlags &^= protocol.FlagLocalReceiveOnly
+				batchAppend(file.ConvertDeletedToFileInfo(), snap)
+				changes++
+			case file.IsDeleted() && file.LocalFlags != f.localFlags:
+				// No need to bump the version for a file that was
+				// and is deleted and just the local flags changed.
+				file.LocalFlags = f.localFlags
+				batchAppend(file.ConvertDeletedToFileInfo(), snap)
+				changes++
 			}
 
-			// Check for deleted, locally changed items that noone else has.
-			if f.localFlags&protocol.FlagLocalReceiveOnly == 0 {
-				return true
-			}
-			if !fi.IsDeleted() || !fi.IsReceiveOnlyChanged() || len(snap.Availability(fi.FileName())) > 0 {
-				return true
-			}
-			nf := fi.(db.FileInfoTruncated).ConvertDeletedToFileInfo()
-			nf.LocalFlags = 0
-			nf.Version = protocol.Vector{}
-			batchAppend(nf, snap)
-			changes++
-
 			return true
 		})
 
diff --git a/lib/model/model_test.go b/lib/model/model_test.go
index 242db0a07..f6df87692 100644
--- a/lib/model/model_test.go
+++ b/lib/model/model_test.go
@@ -3943,6 +3943,47 @@ func TestAddFolderCompletion(t *testing.T) {
 	}
 }
 
+func TestScanDeletedROChangedOnSR(t *testing.T) {
+	w, fcfg := tmpDefaultWrapper()
+	fcfg.Type = config.FolderTypeReceiveOnly
+	waiter, _ := w.SetFolder(fcfg)
+	waiter.Wait()
+	m := setupModel(w)
+	defer cleanupModel(m)
+	name := "foo"
+	ffs := fcfg.Filesystem()
+
+	must(t, writeFile(ffs, name, []byte(name), 0644))
+	m.ScanFolders()
+
+	file, ok := m.CurrentFolderFile(fcfg.ID, name)
+	if !ok {
+		t.Fatal("file missing in db")
+	}
+	// A remote must have the file, otherwise the deletion below is
+	// automatically resolved as not a ro-changed item.
+	m.IndexUpdate(device1, fcfg.ID, []protocol.FileInfo{file})
+
+	must(t, ffs.Remove(name))
+	m.ScanFolders()
+
+	if receiveOnlyChangedSize(t, m, fcfg.ID).Deleted != 1 {
+		t.Fatal("expected one receive only changed deleted item")
+	}
+
+	fcfg.Type = config.FolderTypeSendReceive
+	waiter, _ = w.SetFolder(fcfg)
+	waiter.Wait()
+	m.ScanFolders()
+
+	if receiveOnlyChangedSize(t, m, fcfg.ID).Deleted != 0 {
+		t.Fatal("expected no receive only changed deleted item")
+	}
+	if localSize(t, m, fcfg.ID).Deleted != 1 {
+		t.Fatal("expected one local deleted item")
+	}
+}
+
 func testConfigChangeClosesConnections(t *testing.T, expectFirstClosed, expectSecondClosed bool, pre func(config.Wrapper), fn func(config.Wrapper)) {
 	t.Helper()
 	wcfg, _ := tmpDefaultWrapper()