* * boot-9.scm (using-readline?): New procedure: Returns #t if

	readline is used by the repl run by this thread.
	(handle-system-error): Print "Backtrace:" before backtrace since
	this is no longer done by display-backtrace.

diff --git a/ice-9/boot-9.scm b/ice-9/boot-9.scm
index 3f7d965..c38ad1e 100644 (file)
--- a/ice-9/boot-9.scm
+++ b/ice-9/boot-9.scm
@@ -2580,6 +2580,7 @@
          ((memq 'backtrace (debug-options-interface))
           (run-hook before-backtrace-hook)
           (newline cep)
+          (display "Backtrace:\n")
           (display-backtrace (fluid-ref the-last-stack) cep)
           (newline cep)
           (run-hook after-backtrace-hook)))
@@ -2969,6 +2970,12 @@
 ;; (set-current-output-port outp)
 ;; (set-current-error-port errp)
 
+(define using-readline?
+  (let ((using-readline? (make-fluid)))
+     (make-procedure-with-setter
+      (lambda () (fluid-ref using-readline?))
+      (lambda (v) (fluid-set! using-readline? v)))))
+
 ;; this is just (scm-style-repl) with a wrapper to install and remove 
 ;; signal handlers.
 (define (top-repl)