From fafd05f014a95fd2c646a966b66c30d9811c546b Mon Sep 17 00:00:00 2001
From: "Alexander J. Vincent" <ajvincent@gmail.com>
Date: Thu, 30 Nov 2017 23:42:50 -0800
Subject: [PATCH] #137:  CodeMirror tail text locks must deny appending to end
 of file.

---
 docs/gui/utilities/CodeMirrorManager.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/docs/gui/utilities/CodeMirrorManager.js b/docs/gui/utilities/CodeMirrorManager.js
index f101d804..1e28d487 100644
--- a/docs/gui/utilities/CodeMirrorManager.js
+++ b/docs/gui/utilities/CodeMirrorManager.js
@@ -35,7 +35,12 @@ const CodeMirrorManager = window.CodeMirrorManager = {
   getTextLock: function(editor, startLine, endLine)
   {
     const doc = editor.getDoc();
-    const options = Object.freeze({ readOnly: true, className: "readOnly" });
+    const options = { readOnly: true, className: "readOnly" };
+    if (startLine === 0)
+      options.inclusiveLeft = true;
+    if (endLine === Infinity)
+      options.inclusiveRight = true;
+    Object.freeze(options);
     let mark = doc.markText(
       {line: startLine, ch: 0},
       {line: endLine, ch: 0},