From: Paul Eggert <eggert@union>
Date: Mon, 27 Nov 2017 03:15:14 +0000 (-0800)
Subject: Harden exec_byte_code against redefining 'error'
X-Git-Tag: emacs-26.0.91~238
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=ac64fdb248d791b204cf579f878f8542ded0d067;p=emacs.git

Harden exec_byte_code against redefining 'error'

Problem discovered by configuring with --enable-gcc-warnings on
Ubuntu 17.10 x86-64 with gcc (Ubuntu 7.2.0-8ubuntu3).
* src/bytecode.c (exec_byte_code): Call the C error function
instead of the Lisp one, so that the Emacs interpreter does not go
haywire if the user redefines the Lisp error function.
---

diff --git a/src/bytecode.c b/src/bytecode.c
index ebaf3c3a7fc..8746568f166 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -1346,10 +1346,8 @@ exec_byte_code (Lisp_Object bytestr, Lisp_Object vector, Lisp_Object maxdepth,
 	  /* Actually this is Bstack_ref with offset 0, but we use Bdup
 	     for that instead.  */
 	  /* CASE (Bstack_ref): */
-	  call3 (Qerror,
-		 build_string ("Invalid byte opcode: op=%s, ptr=%d"),
-		 make_number (op),
-		 make_number (pc - 1 - bytestr_data));
+	  error ("Invalid byte opcode: op=%d, ptr=%"pD"d",
+		 op, pc - 1 - bytestr_data);
 
 	  /* Handy byte-codes for lexical binding.  */
 	CASE (Bstack_ref1):