#594 HANDLER-BIND cannot handle handlers defined using CONSTANTLY

[Sam Steingold]

(compile nil (lambda (arg)
(handler-bind ((error (constantly nil))) (car arg))))
*** - Compiler bug!! Occurred in ASSEMBLE-LAP at (HANDLER-BEGIN).

this bug was present before the 2005-01-21 patch which made %HANDLER-BIND have a function syntax.
it is now (after the 2011-03-29 patch which fixed bug#3147908) present again.
note that asdf.lisp cannot be compiled ootb until this bug is fixed.

[Sam Steingold]

the following seems to work around the bug:
(defun fix-handler-begin (list)
"replace (... (HANDLER-BEGIN) ...) with (... (HANDLER-BEGIN&PUSH) (POP) ...)"
(do ((tail list (cdr tail)))
((endp tail) list)
(when (equal (car tail) '(SYS::HANDLER-BEGIN))
(setf (car tail) '(SYS::HANDLER-BEGIN&PUSH)
(cdr tail) (cons '(SYS::POP) (cdr tail))
tail (cddr tail)))))

(trace (sys::insert-combined-LAPs :post (fix-handler-begin (car *trace-values*))))

I wonder if this is the right fix...

[Sam Steingold]

thank you for your bug report.
the bug has been fixed in the source tree (mercurial/hg).
you can either wait for the next release (recommended)
or check out the current mercurial tree (see http://clisp.org\)
and build CLISP from the sources (be advised that between
releases the source tree is very unstable and may not even build
on your platform).