post_mortem: to test $! *before* running debug_at_ext or else we may get an erroneous message:   ruby-debug-base.rb:162:in `current_context': Debugger.start is not called yet. (RuntimeError)
post_mortem: to test $! *before* running debug_at_ext or else we may get an erroneous message:
  ruby-debug-base.rb:162:in `current_context': Debugger.start is not called yet. (RuntimeError)

A simple test case to show the problem:

"require rubygems"
"require ruby-debug"
Debugger.start
Debugger.post_mortem
exit   # Causes us to incorrectly give the above error


git-svn-id: 7ffbd09614c8d739a966cfae413e2c1c0f4cb91b@219 453b2852-3d18-0410-866e-d09c099698e4

ruby-debug/ruby-debug-extra,ruby-debug/ruby-debug-extra