Local variable corruption, with handler-bind inside loop

In the following code the local variables of F get corrupted:

(in-package :cl-user)

(defun f ()
  (let ((val 1234)
        (x 3))

    (loop while (> x 0)
        do (block try-except-stmt
             (handler-bind
                 ((error (lambda (e)
                           (warn "Error: ~S" e)
                           ;; Without the next expression, the function works as expected                                                                                            
                           (return-from try-except-stmt nil))))
               (my-call (lambda ()
                          (warn "x: ~S val: ~S" x val)
                          (decf x 1)
                          (warn "new x: ~S" x))))))))

(defun my-call (func)
  (funcall func))

The expected output occurs if the code is run interpreted:

> (load "/tmp/x.lisp")

#P"/tmp/x.lisp"
> (f)
;;; Warning: x: 3 val: 1234
;;; Warning: new x: 2
;;; Warning: x: 2 val: 1234
;;; Warning: new x: 1
;;; Warning: x: 1 val: 1234
;;; Warning: new x: 0

NIL

But with F compiled the output is wrong. The variables X and VAL get bogus values:

> (compile 'f)

;;; OPTIMIZE levels: Safety=2, Space=0, Speed=3, Debug=0
;;;
;;; End of Pass 1.
F
NIL
NIL
> (f)
;;; Warning: x: 3 val: 1234
;;; Warning: new x: 2
;;; Warning: x: 1725 val: 2
;;; Warning: new x: 1724
;;; Warning: x: 1728 val: 1724
;;; Warning: new x: 1727
;;; Warning: x: 1731 val: 1727
;;; Warning: new x: 1730
;;; Warning: x: 1734 val: 1730
...

(lisp-implementation-version) "16.1.3"
(ext:lisp-implementation-vcs-id) "226dd3577510bb6c6a2a06db10e857dfd788996e"
(software-type) "Linux"
(software-version) "3.16.0-4-amd64"
(machine-type) "x86_64"
*features* QUICKLISP ASDF-PACKAGE-SYSTEM ASDF3.1 ASDF3 ASDF2 ASDF OS-UNIX NON-BASE-CHARS-EXIST-P ASDF-UNICODE WALKER CDR-1 CDR-5 LINUX FORMATTER CDR-7 ECL-WEAK-HASH LITTLE-ENDIAN ECL-READ-WRITE-LOCK LONG-LONG UINT64-T UINT32-T UINT16-T RELATIVE-PACKAGE-NAMES LONG-FLOAT UNICODE DFFI CLOS-STREAMS CMU-FORMAT UNIX ECL-PDE DLOPEN CLOS THREADS BOEHM-GC ANSI-CL COMMON-LISP IEEE-FLOATING-POINT CDR-14 PREFIXED-API FFI X86_64 COMMON ECL

The test code is extracted from a CLPython test case.

I have a solution on that, the generation of closure code in that particular case is wrong. I'm verifying if is limited to return-from or is a problem with other form.

mentioned in issue #353

any progress on that?

changed milestone to %ECL 16.2.0

I have a partial solution but before submit the pull request I'm studying the cmp. If you already have some idea on solving that please go ahead, don't wait for me.