From: Eli Zaretskii <eliz@gnu.org>
Date: Mon, 13 Mar 2017 16:15:09 +0000 (+0200)
Subject: Fix bidi paragraph direction when inserting text at newline
X-Git-Tag: emacs-26.0.90~578
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=f591765e2b6b9ec3fa3ff647c77a10c984f78133;p=emacs.git

Fix bidi paragraph direction when inserting text at newline

* src/insdel.c (invalidate_buffer_caches): Invalidate the bidi
paragraph cache when inserting immediately after a newline.
(Bug#26083)
---

diff --git a/src/insdel.c b/src/insdel.c
index e4ad9a2dec3..0a2e07a343f 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -2001,18 +2001,21 @@ invalidate_buffer_caches (struct buffer *buf, ptrdiff_t start, ptrdiff_t end)
      see below).  */
   if (buf->bidi_paragraph_cache)
     {
-      if (start != end
-	  && start > BUF_BEG (buf))
+      if (start > BUF_BEG (buf))
 	{
 	  /* If we are deleting or replacing characters, we could
 	     create a paragraph start, because all of the characters
 	     from START to the beginning of START's line are
 	     whitespace.  Therefore, we must extend the region to be
-	     invalidated up to the newline before START.  */
+	     invalidated up to the newline before START.  Similarly,
+	     if we are inserting characters immediately after a
+	     newline, we could create a paragraph start if the
+	     inserted characters start with a newline.  */
 	  ptrdiff_t line_beg = start;
 	  ptrdiff_t start_byte = buf_charpos_to_bytepos (buf, start);
+	  int prev_char = BUF_FETCH_BYTE (buf, start_byte - 1);
 
-	  if (BUF_FETCH_BYTE (buf, start_byte - 1) != '\n')
+	  if ((start == end) == (prev_char == '\n'))
 	    {
 	      struct buffer *old = current_buffer;