2 files changed, 55 insertions, 2 deletions
diff --git a/internal/engine/apply.go b/internal/engine/apply.go
index 46026ba..0d894c6 100644
--- a/internal/engine/apply.go
+++ b/internal/engine/apply.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -990,7 +991,7 @@ func (e *Engine) declineUndoFile(f UndoFile, j *journal.Writer, run string) (Fil
 			return FileResult{}, err
 		}
 	}
-	return FileResult{Steps: steps}, nil
+	return FileResult{File: undoFileIdentity(f), Steps: steps}, nil
 }
 
 // undoFile executes every step of f in order (already last-original-step
@@ -1034,7 +1035,16 @@ func (e *Engine) undoFile(f UndoFile, j *journal.Writer, run string) (FileResult
 			return FileResult{}, err
 		}
 	}
-	return FileResult{Steps: steps}, nil
+	return FileResult{File: undoFileIdentity(f), Steps: steps}, nil
+}
+
+// undoFileIdentity is all an undo result can honestly say about the file it
+// reversed: the log records its path relative to the directory root and
+// nothing else - the file's size, mode and times belong to a state that no
+// longer exists. A front end showing a row per file matches on Rel (GUI
+// design §4); it must not read the rest.
+func undoFileIdentity(f UndoFile) scan.File {
+	return scan.File{Rel: f.File, Name: path.Base(f.File)}
 }
 
 // runUndoStep actually carries out one reversal. It reuses apply.StepResult
diff --git a/internal/engine/apply_test.go b/internal/engine/apply_test.go
index 104fb73..142e4d2 100644
--- a/internal/engine/apply_test.go
+++ b/internal/engine/apply_test.go
@@ -5,6 +5,7 @@ package engine
 import (
 	"context"
 	"os"
+	"path"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -461,6 +462,48 @@ func TestApplyUndoRestoresMovedFile(t *testing.T) {
 	}
 }
 
+// TestApplyUndoNamesItsFiles: every file in an undo result says which file
+// it is, reversed or declined, so a front end showing a row per file can
+// put each outcome on the right row (GUI design §4). The log is the only
+// source of that name, so Rel and Name are all an undo result can carry.
+func TestApplyUndoNamesItsFiles(t *testing.T) {
+	h, e, dp, j, run := applyFixture(t)
+	if _, err := e.Apply(context.Background(), dp, map[string]bool{"a.pdf": true}, j, run); err != nil {
+		t.Fatal(err)
+	}
+	j.Close()
+
+	j2, err := journal.Open(filepath.Join(h, ".local", "state", "krino", "krino.log"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer j2.Close()
+
+	// Declined first - nothing is reversed, so the run is still undoable -
+	// then reversed for real. Both paths must name the file.
+	for _, declined := range []bool{true, false} {
+		up, err := e.PlanUndo(run)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(up.Files) != 1 || up.Files[0].Refused != "" {
+			t.Fatalf("undo plan = %+v", up.Files)
+		}
+		up.Files[0].Declined = declined
+		res, err := e.ApplyUndo(context.Background(), up, j2, journal.NewRunID(time.Now()))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(res.Files) != 1 {
+			t.Fatalf("declined=%v: result files = %+v, want one", declined, res.Files)
+		}
+		fr := res.Files[0]
+		if fr.File.Rel != "a.pdf" || fr.File.Name != path.Base("a.pdf") {
+			t.Errorf("declined=%v: file = %+v, want a.pdf", declined, fr.File)
+		}
+	}
+}
+
 // TestApplyUndoSkipsRefusedFiles: rule 4 enforced at execution time too - a
 // refused file must come back from ApplyUndo untouched.
 func TestApplyUndoSkipsRefusedFiles(t *testing.T) {