From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 9 Feb 2015 02:14:14 +0000 (-0800)
Subject: Fix bidi_explicit_dir_char undefined behavior
X-Git-Tag: emacs-25.0.90~2008^2~55
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=237171731157095f5cc46b0f6f6205e3b4ba9f00;p=emacs.git

Fix bidi_explicit_dir_char undefined behavior

* bidi.c (bidi_explicit_dir_char): Avoid subscript error when
argument is BIDI_EOB.  This can happen in bidi_level_of_next_char.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 017b8f15e3b..3b2c9a6777f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2015-02-09  Paul Eggert  <eggert@cs.ucla.edu>
 
+	Fix bidi_explicit_dir_char undefined behavior
+	* bidi.c (bidi_explicit_dir_char): Avoid subscript error when
+	argument is BIDI_EOB.  This can happen in bidi_level_of_next_char.
+
 	Better distinguish infinite from invalid times
 	* editfns.c (check_time_validity): New function.
 	(decode_time_components): Return int, not bool.
diff --git a/src/bidi.c b/src/bidi.c
index cbc1820c2a5..e5e08c6a252 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -1799,6 +1799,11 @@ bidi_explicit_dir_char (int ch)
 
   if (!bidi_initialized)
     emacs_abort ();
+  if (ch < 0)
+    {
+      eassert (ch == BIDI_EOB);
+      return false;
+    }
   ch_type = (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch));
   return (ch_type == LRE || ch_type == LRO
 	  || ch_type == RLE || ch_type == RLO