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* lisp/emacs-lisp/cl-macs.el (cl-expr-contains): Handle cons cells

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whose cdr is not a cons cell correctly.

Fixes: debbugs:11038
This commit is contained in:
Christopher Schmidt 2012-05-06 11:38:30 -04:00 • committed by Stefan Monnier
parent 491503ddd2
commit e129292c44
2 changed files with 17 additions and 7 deletions
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7
lisp/emacs-lisp/cl-macs.el
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@ -143,11 +143,16 @@
;;; Count number of times X refers to Y. Return nil for 0 times.
(defun cl-expr-contains (x y)
;; FIXME: This is naive, and it will count Y as referred twice in
;; (let ((Y 1)) Y) even though it should be 0. Also it is often called on
;; non-macroexpanded code, so it may also miss some occurrences that would
;; only appear in the expanded code.
(cond ((equal y x) 1)
((and (consp x) (not (memq (car-safe x) '(quote function function*))))
(let ((sum 0))
(while x
(while (consp x)
(setq sum (+ sum (or (cl-expr-contains (pop x) y) 0))))
(setq sum (+ sum (or (cl-expr-contains x y) 0)))
(and (> sum 0) sum)))
(t nil)))