merges r21578 from trunk into ruby_1_9_1.

* thread.c (call_trace_proc): as Matz said ([ruby-core:21183]),
  should skip rb_str_new2() if rb_sourcefile() returns NULL.
  rb_sourcefile() returns NULL if frame is toplevel of Fiber.
  [ruby-core:21161] [Bug #985]

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@21593 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Fri Jan 16 01:42:50 2009  Koichi Sasada  <ko1@atdot.net>
+
+	* thread.c (call_trace_proc): as Matz said ([ruby-core:21183]),
+	  should skip rb_str_new2() if rb_sourcefile() returns NULL.
+	  rb_sourcefile() returns NULL if frame is toplevel of Fiber.
+	  [ruby-core:21161] [Bug #985]
+
 Fri Jan  9 12:29:46 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* common.mk (test-sample), rubytest.rb: use runruby.rb

thread.c

@@ -3591,8 +3591,9 @@ static VALUE
 call_trace_proc(VALUE args, int tracing)
 {
     struct call_trace_func_args *p = (struct call_trace_func_args *)args;
+    const char *srcfile = rb_sourcefile();
     VALUE eventname = rb_str_new2(get_event_name(p->event));
-    VALUE filename = rb_str_new2(rb_sourcefile());
+    VALUE filename = srcfile ? rb_str_new2(srcfile) : Qnil;
     VALUE argv[6];
     int line = rb_sourceline();
     ID id = 0;
@@ -3621,7 +3622,7 @@ call_trace_proc(VALUE args, int tracing)
     argv[1] = filename;
     argv[2] = INT2FIX(line);
     argv[3] = id ? ID2SYM(id) : Qnil;
-    argv[4] = p->self ? rb_binding_new() : Qnil;
+    argv[4] = (p->self && srcfile) ? rb_binding_new() : Qnil;
     argv[5] = klass ? klass : Qnil;
 
     return rb_proc_call_with_block(p->proc, 6, argv, Qnil);