From: Mattias Engdegård <mattiase@acm.org>
Date: Wed, 26 Jul 2023 16:39:36 +0000 (+0200)
Subject: Fix broken byte-compilation of unary comparisons
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=27944247d161f0ed65bbb34959c4493f7984987a;p=emacs.git

Fix broken byte-compilation of unary comparisons

* lisp/emacs-lisp/byte-opt.el (byte-opt--nary-comparison):
Fix a typo causing miscompilation of code such as (OP X),
where OP is <, >, <=, >= or =.
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp-tests--test-cases): Add test case.

Reported by Richard Copley.
---

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 0be6ae65aab..3005d69ae88 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -973,7 +973,7 @@ for speeding up processing.")
   (let ((nargs (length (cdr form))))
     (cond
      ((= nargs 1)
-      `(progn (cadr form) t))
+      `(progn ,(cadr form) t))
      ((>= nargs 3)
       ;; At least 3 arguments: transform to N-1 binary comparisons,
       ;; since those have their own byte-ops which are particularly
diff --git a/test/lisp/emacs-lisp/bytecomp-tests.el b/test/lisp/emacs-lisp/bytecomp-tests.el
index b549ae1fe09..593fd117685 100644
--- a/test/lisp/emacs-lisp/bytecomp-tests.el
+++ b/test/lisp/emacs-lisp/bytecomp-tests.el
@@ -780,6 +780,11 @@ inner loops respectively."
     ;; (+ 0 -0.0) etc
     (let ((x (bytecomp-test-identity -0.0)))
       (list x (+ x) (+ 0 x) (+ x 0) (+ 1 2 -3 x) (+ 0 x 0)))
+
+    ;; Unary comparisons: keep side-effect, return t
+    (let ((x 0))
+      (list (= (setq x 1))
+            x))
     )
   "List of expressions for cross-testing interpreted and compiled code.")