load.c: use local variable

* load.c (rb_load_internal): use local variable th instead of
  GET_THREAD() for each time.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43498 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
load.c: suppress warning

* load.c (rb_load_internal): split to suppress false "clobbered"
  warning by gcc 4.4.5.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43499 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
string.c: export rb_str_scrub

* string.c (rb_str_scrub): export with fixed length arguments, and
  allow nil as replacement string instead of omitting.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43500 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_m17n.rb: nil replacement

* test/ruby/test_m17n.rb (test_scrub, test_scrub_bang): now explicit
  nil is allowed as replacement.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43501 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
gc.c: zombie is not alive

* gc.c (is_live_object): finalizer may not run because of lazy-sweep.
  [ruby-dev:47786] [Bug #9069]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43502 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
string.c: fix typo

* string.c (rb_str_scrub): fix typo, should yield invalid byte
  sequence to be scrubbed.  reported by znz at IRC.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43503 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
transcode.c: fix segv in String.encode!

* transcode.c (str_transcode0): fix segv in String.encode!.  now
  rb_str_scrub() can return nil.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43504 b2dd03c8-39d4-4d8f-98ff-823fe69b080e