[DOC] Re-apply r11000, 41256fd43275c8bf66460510da7ab958a802e2a2

* eval.c (rb_thread_kill): fix Thread#kill docs, which returns
  the thread object in all cases.

From: why the lucky stiff <why@ruby-lang.org>

1 files changed, 6 insertions, 8 deletions

diff --git a/thread.c b/thread.c
index caec3049ee..55df74d7d3 100644
--- a/thread.c
+++ b/thread.c
@@ -2424,15 +2424,13 @@ thread_raise_m(int argc, VALUE *argv, VALUE self)
 
 /*
  *  call-seq:
- *     thr.exit        -> thr or nil
- *     thr.kill        -> thr or nil
- *     thr.terminate   -> thr or nil
+ *     thr.exit        -> thr
+ *     thr.kill        -> thr
+ *     thr.terminate   -> thr
  *
- *  Terminates +thr+ and schedules another thread to be run.
- *
- *  If this thread is already marked to be killed, #exit returns the Thread.
- *
- *  If this is the main thread, or the last thread, exits the process.
+ *  Terminates +thr+ and schedules another thread to be run, returning
+ *  the terminated Thread.  If this is the main thread, or the last
+ *  thread, exits the process.
  */
 
 VALUE