bug#31072: 27.0.50; Assertion failure in defvar

[Philipp Stephani]

Philipp <p.stephani2@gmail.com> schrieb am Fr., 6. Apr. 2018 um 03:25 Uhr:

Loading the following file triggers an assertion failure:

;;; -*- lexical-binding: t; -*-
(defvar 1)

$ emacs -Q -batch -l /tmp/crash.el
eval.c:772: Emacs fatal error: assertion failed: SYMBOLP (sym)
Fatal error 6: Abort trapAbort trap: 6

This is because Fdefvar lacks a CHECK_SYMBOL in the second branch
(lexical binding but only one argument)

Here is a patch. 

0001-Avoid-undefined-behavior-in-defvar-Bug-31072.txt
Description: Text document