From 7c011261b702092e005c901972af405c7b7c9f3b Mon Sep 17 00:00:00 2001
From: "Richard M. Stallman" <rms@gnu.org>
Date: Sat, 31 Jul 1993 05:53:23 +0000
Subject: [PATCH] (Fnewline): Disable the "insert one position before"
 optimization if it would screw up text property behavior.

---
 src/cmds.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/cmds.c b/src/cmds.c
index df8cd6d0645..43c919d7c3f 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -254,7 +254,13 @@ In Auto Fill mode, if no numeric arg, break the preceding line if it's long.")
 
   flag = point > BEGV && FETCH_CHAR (point - 1) == '\n';
   if (flag)
-    SET_PT (point - 1);
+    /* We cannot use this optimization if properties change
+       in the vicinity.
+       ??? We need to check for change hook properties, etc.  */
+#ifdef USE_TEXT_PROPERTIES
+    if (point - 1 > BEGV && ! property_change_between_p (point - 2, point))
+#endif
+      SET_PT (point - 1);
 
   while (XINT (arg) > 0)
     {
-- 
2.39.5