From 24d86a87890bd21f8ba23e4c2bb8cfa25db00b3c Mon Sep 17 00:00:00 2001
From: Marijn Haverbeke <marijn@haverbeke.nl>
Date: Tue, 28 Jun 2016 11:40:20 +0200
Subject: [PATCH] Stop blocking selection-undo in read-only mode

Closes #4090
---
 lib/codemirror.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/codemirror.js b/lib/codemirror.js
index 476ab2e6e5..7be2fac1db 100644
--- a/lib/codemirror.js
+++ b/lib/codemirror.js
@@ -4419,7 +4419,7 @@
 
   // Revert a change stored in a document's history.
   function makeChangeFromHistory(doc, type, allowSelectionOnly) {
-    if (doc.cm && doc.cm.state.suppressEdits) return;
+    if (doc.cm && doc.cm.state.suppressEdits && !allowSelectionOnly) return;
 
     var hist = doc.history, event, selAfter = doc.sel;
     var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;