bug#41005: problem with rendering Persian text in Emacs 27

[hossein valizadeh <valizadeh.ho@gmail.com>]

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I tested  Pip Cet's patch on Emacs 27.0.91 and everything was fine.
In both cases (auto-fill-mode & column-number-mode) There was no
confusion in the letters; and all the words were displayed correctly.

Thanks.

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From 18d0e15ac298f40951ddeeec56e9d87c01f51798 Mon Sep 17 00:00:00 2001
From: Pip Cet <pipcet@gmail.com>
Date: Fri, 5 Jun 2020 12:54:01 +0000
Subject: [PATCH] Test patch for bug#41005

---
 src/composite.c | 4 +++-
 src/indent.c    | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/composite.c b/src/composite.c
index 2c589e4f3a..13421a80da 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -1213,7 +1213,9 @@ composition_reseat_it (struct composition_it *cmp_it, ptrdiff_t charpos,
 	continue;
       if (charpos < endpos)
 	{
-	  if ((bidi_level & 1) == 0)
+	  if (bidi_level < 0)
+	    direction = Qnil;
+	  else if ((bidi_level & 1) == 0)
 	    direction = QL2R;
 	  else
 	    direction = QR2L;
diff --git a/src/indent.c b/src/indent.c
index c0b4c13b2c..581323b91e 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -596,7 +596,7 @@ scan_for_column (ptrdiff_t *endpos, EMACS_INT *goalcol, ptrdiff_t *prevcol)
       if (cmp_it.id >= 0
 	  || (scan == cmp_it.stop_pos
 	      && composition_reseat_it (&cmp_it, scan, scan_byte, end,
-					w, NEUTRAL_DIR, NULL, Qnil)))
+					w, -1, NULL, Qnil)))
 	composition_update_it (&cmp_it, scan, scan_byte, Qnil);
       if (cmp_it.id >= 0)
 	{
@@ -1504,7 +1504,7 @@ compute_motion (ptrdiff_t from, ptrdiff_t frombyte, EMACS_INT fromvpos,
 	  if (cmp_it.id >= 0
 	      || (pos == cmp_it.stop_pos
 		  && composition_reseat_it (&cmp_it, pos, pos_byte, to, win,
-					    NEUTRAL_DIR, NULL, Qnil)))
+					    -1, NULL, Qnil)))
 	    composition_update_it (&cmp_it, pos, pos_byte, Qnil);
 	  if (cmp_it.id >= 0)
 	    {
-- 
2.27.0.rc0