From: Eli Zaretskii <eliz@gnu.org>
Date: Tue, 20 Oct 2020 15:27:47 +0000 (+0300)
Subject: Avoid assertion violations in malformed Unicode escapes
X-Git-Tag: emacs-28.0.90~5524
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=d3c3fe781424c866ad64ce9a8e3b649b30a0b5ae;p=emacs.git

Avoid assertion violations in malformed Unicode escapes

* src/lread.c (read_escape): Produce better diagnostic for
malformed \u Unicode escapes, while avoiding assertion violation
when READCHAR returns -1 because the input is exhausted.
(Bug#44084)
---

diff --git a/src/lread.c b/src/lread.c
index 4b788e99407..a3d5fd7bb81 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2573,6 +2573,13 @@ read_escape (Lisp_Object readcharfun, bool stringp)
 	while (++count <= unicode_hex_count)
 	  {
 	    c = READCHAR;
+	    if (c < 0)
+	      {
+		if (unicode_hex_count > 4)
+		  error ("Malformed Unicode escape: \\U%x", i);
+		else
+		  error ("Malformed Unicode escape: \\u%x", i);
+	      }
 	    /* `isdigit' and `isalpha' may be locale-specific, which we don't
 	       want.  */
 	    int digit = char_hexdigit (c);