Strategy: when an instrumented function gets re-evaluated, save the former value of its symbol's `edebug' property in the new propery `ghost-edebug'. If this function is still being edebugged, edebug will then access its info from this new property. Also fix the bug whereby compile-defun'ing an instrumented function prevents the function being re-instrumented by I (edebug-instrument-callee). * lisp/emacs-lisp/edebug.el (edebug-get-edebug-or-ghost): New function. (edebug-read-and-maybe-wrap-form1): save value of `edebug' property in 'ghost-edebug'. (edebug-make-form-wrapper): Set value of `ghost-edebug' to nil. (edebug-make-form-wrapper, edebug-find-stop-point, edebug-next-break-point) (edebug-modify-breakpoint, edebug--overlay-breakpoints, edebug-set-breakpoint) (edebug-unset-breakpoints, edebug-toggle-disable-breakpoint) (edebug--backtrace-goto-source, edebug-display-freq-count) (edebug-set-conditional-breakpoint): Use edebug-get-edebug-or-ghost to access edebug information. (edebug-instrument-function): Also check a function is a cons before declaring it "already instrumented".