* io.c (rb_io_close_read): keep fptr in write_io to be discarded, to fix freed pointer access when it is in use by other threads, and get rid of potential memory/fd leak. * io.c (rb_io_close_write): detach tied IO for writing before closing to get rid of race condition. [ruby-list:49598] * io.c (rb_io_close_read): duplex IO should wait its child process even after close_read.
merge revision(s) 43112,43114,43117,43118: [Backport #8980]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@43482 b2dd03c8-39d4-4d8f-98ff-823fe69b080e