Hi,

Today I used Ruby-1.5 debugger after a long time, and I found 'list'
command did not work.  It seems that SCRIPT_LINES__ is not set.
I could not retrieve why it is...

Apart from this, here is patch for debug.rb to on/off tracer.
Matz, I do not know well about Ruby debugger thread aware version,
is this right way to patch?

// NaHi


--- debug.rb.dist	Tue May  9 15:59:49 2000
+++ debug.rb	Fri Jun 23 22:00:12 2000
@@ -8,4 +8,12 @@ end
 SCRIPT_LINES__ = {} unless defined? SCRIPT_LINES__
 
+require 'tracer'
+class Tracer
+  def Tracer.trace_func(*vars)
+    Single.trace_func *vars
+  end
+end
+
+
 class DEBUGGER__
   class Mutex
@@ -81,4 +89,5 @@ class DEBUGGER__
       @frames = []
       @finish_pos = 0
+      @trace = false
     end
 
@@ -217,4 +226,18 @@ class DEBUGGER__
 
 	  case input
+	  when /^\s*tr(?:ace)?(?:\s+(on|off))?$/
+	    if !defined?( $1 )
+	      @trace = !@trace
+	    elsif $1 == 'on'
+	      @trace = true
+	    else
+	      @trace = false
+	    end
+	    if @trace
+	      stdout.print "Trace on\n"
+	    else
+	      stdout.print "Trace off\n"
+	    end
+
 	  when /^\s*b(?:reak)?\s+((?:.*?+:)?.+)$/
 	    pos = $1
@@ -446,4 +469,5 @@ Commands
   down[ nn]                  move to lower frame
   fin[ish]                   return to outer frame
+  tr[ace][ (on|off)]         set trace mode
   q[uit]                     exit from debugger
   v[ar] g[lobal]             show global variables
@@ -573,4 +597,5 @@ EOHELP
 
     def trace_func(event, file, line, id, binding, klass)
+      Tracer.trace_func(event, file, line, id, binding) if @trace
       @file = file
       @line = line