master ddc8020 2/2: Don't increment array index in cl-loop twice (Bug#40727)

[Noam Postavsky]

branch: master
commit ddc8020327604b92e7e830708933f62a22f48f62
Author: Noam Postavsky <address@hidden>
Commit: Noam Postavsky <address@hidden>

    Don't increment array index in cl-loop twice (Bug#40727)
    
    * lisp/emacs-lisp/cl-macs.el (cl--parse-loop-clause): Put the temp-idx
    increment in cl--loop-body, leaving just the side-effect free testing
    of the index for both cl--loop-body and cl--loop-conditions.
    * test/lisp/emacs-lisp/cl-macs-tests.el (cl-macs-loop-and-arrays):
    Extend test to cover this case.
---
 lisp/emacs-lisp/cl-macs.el            | 3 ++-
 test/lisp/emacs-lisp/cl-macs-tests.el | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/lisp/emacs-lisp/cl-macs.el b/lisp/emacs-lisp/cl-macs.el
index fef8786..3317c58 100644
--- a/lisp/emacs-lisp/cl-macs.el
+++ b/lisp/emacs-lisp/cl-macs.el
@@ -1320,8 +1320,9 @@ For more details, see Info node `(cl)Loop Facility'.
                      (temp-idx (make-symbol "--cl-idx--")))
                  (push (list temp-vec (pop cl--loop-args)) loop-for-bindings)
                  (push (list temp-idx -1) loop-for-bindings)
+                  (push `(setq ,temp-idx (1+ ,temp-idx)) cl--loop-body)
                  (cl--push-clause-loop-body
-                   `(< (setq ,temp-idx (1+ ,temp-idx)) (length ,temp-vec)))
+                   `(< ,temp-idx (length ,temp-vec)))
                  (if (eq word 'across-ref)
                      (push (list var `(aref ,temp-vec ,temp-idx))
                            cl--loop-symbol-macs)
diff --git a/test/lisp/emacs-lisp/cl-macs-tests.el 
b/test/lisp/emacs-lisp/cl-macs-tests.el
index 77609a4..983e79a 100644
--- a/test/lisp/emacs-lisp/cl-macs-tests.el
+++ b/test/lisp/emacs-lisp/cl-macs-tests.el
@@ -43,6 +43,9 @@
   "Bug#40727"
   (should (equal (cl-loop for y = (- (or x 0)) and x across [1 2]
                           collect (cons x y))
+                 '((1 . 0) (2 . -1))))
+  (should (equal (cl-loop for x across [1 2] and y = (- (or x 0))
+                          collect (cons x y))
                  '((1 . 0) (2 . -1)))))
 
 (ert-deftest cl-macs-loop-destructure ()