1 files changed, 32 insertions, 7 deletions

diff --git a/internal/journal/read.go b/internal/journal/read.go
index de06422..48cd6b0 100644
--- a/internal/journal/read.go
+++ b/internal/journal/read.go
@@ -81,9 +81,12 @@ func ReversedSteps(path, runID string) (map[ReversedKey]int, error) {
 	return out, nil
 }
 
-// Entries returns every entry belonging to runID, in file order. A line
-// that fails to parse is skipped, but Entries fails closed within the run's
-// own window - from its run-start line to its run-end line, or to end of
+// Entries returns every entry belonging to runID, in file order. Since plan
+// 10 (re-review N1), an unparsable line whose run column names another run
+// is ignored, and one of this run whose directory and file columns are still
+// readable is returned as a "damaged" entry for that file, so undo refuses
+// that file alone. Otherwise a line that fails to parse is skipped, but
+// Entries fails closed within the run's own window - from its run-start line to its run-end line, or to end of
 // file when there is no run-end (a crashed run, which is precisely when
 // corruption is likely): any unparsable line found inside that window sets
 // the returned error, whether or not the line's own Run column can still be
@@ -136,14 +139,25 @@ func Entries(path, runID string) ([]Entry, error) {
 			}
 			continue
 		}
-		if badLine != 0 {
+		run, runFound := runFieldOf(line)
+		if runFound && run != runID {
+			// Another run's damaged line: runs of different directories can
+			// interleave, and it says nothing about this one (re-review N1).
 			continue
 		}
-		if inWindow {
-			badLine = i + 1
+		ours := inWindow || (runFound && run == runID)
+		if !ours {
+			continue
+		}
+		if dir, file, ok := fileFieldsOf(line); ok {
+			// A line of this run cut or damaged where its file is still
+			// readable: that file's chain may be missing a step, so it is
+			// returned as damaged and PlanUndo refuses just that file; the
+			// rest of the run stays undoable (re-review N1).
+			out = append(out, Entry{Run: runID, Dir: dir, File: file, Action: "damaged", Status: "damaged", Detail: fmt.Sprintf("line %d", i+1)})
 			continue
 		}
-		if run, found := runFieldOf(line); found && run == runID {
+		if badLine == 0 {
 			badLine = i + 1
 		}
 	}
@@ -167,6 +181,17 @@ func runFieldOf(line string) (string, bool) {
 	return unescape(f[1]), true
 }
 
+// fileFieldsOf best-effort extracts a line's directory and file columns when
+// the line otherwise fails to parse; ok is false when the line is cut before
+// them or names no file (a run-start or run-end line).
+func fileFieldsOf(line string) (dir, file string, ok bool) {
+	f := strings.SplitN(line, "\t", 5)
+	if len(f) < 5 || f[3] == "" {
+		return "", "", false
+	}
+	return unescape(f[2]), unescape(f[3]), true
+}
+
 // Runs summarises every run found in the log, newest first. n <= 0 means
 // all. As with Entries, an unparsable line is skipped rather than failing
 // the read - here silently and always, even when it belonged to the run