Allow merging when moving pages

search.go

@@ -335,6 +335,38 @@ func folderIndexRenameSubtree(oldRel, newRel string) {
 	folderIndex.entries = out
 }
 
+// folderIndexMergeSubtree updates the index after a merge move: it drops the
+// source root entry (that folder is gone) and rewrites every descendant's
+// prefix to live under newRel. Unlike folderIndexRenameSubtree it does not add
+// a newRel entry, since the destination folder already exists in the index.
+func folderIndexMergeSubtree(oldRel, newRel string) {
+	oldRel = strings.Trim(oldRel, "/")
+	newRel = strings.Trim(newRel, "/")
+	if oldRel == "" || newRel == "" {
+		return
+	}
+	oldPrefix := oldRel + "/"
+	folderIndex.Lock()
+	defer folderIndex.Unlock()
+	old := folderIndex.entries
+	out := make([]folderEntry, 0, len(old))
+	for _, e := range old {
+		switch {
+		case e.Path == oldRel:
+			continue
+		case strings.HasPrefix(e.Path, oldPrefix):
+			out = append(out, folderEntry{
+				Path:       newRel + "/" + strings.TrimPrefix(e.Path, oldPrefix),
+				NameLower:  e.NameLower,
+				NameTokens: e.NameTokens,
+			})
+		default:
+			out = append(out, e)
+		}
+	}
+	folderIndex.entries = out
+}
+
 // resolveWalkRoot resolves symlinks so WalkDir descends into the real tree
 // even when the configured wiki root is itself a symlink (as on the NAS).
 func resolveWalkRoot(root string) string {