merge revision(s) 42905: [Backport #8884]

	* vm_backtrace.c (vm_backtrace_to_ary): Ignore the second argument if
	  it is nil. [Bug #8884] [ruby-core:57094]

	* test/ruby/test_backtrace.rb (test_caller_with_nil_length):
	  Test for above.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@42925 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 0 deletions

diff --git a/vm_backtrace.c b/vm_backtrace.c
index 6b14137acd..f998d6ccf6 100644
--- a/vm_backtrace.c
+++ b/vm_backtrace.c
@@ -787,6 +787,8 @@ vm_backtrace_to_ary(rb_thread_t *th, int argc, VALUE *argv, int lev_default, int
 
     rb_scan_args(argc, argv, "02", &level, &vn);
 
+    if (argc == 2 && NIL_P(vn)) argc--;
+
     switch (argc) {
       case 0:
 	lev = lev_default + lev_plus;