Fix #2257 pause/resume semantics for stdin

This makes it so that the stdin TTY-wrap stream gets ref'ed on
.resume() and unref'ed on .pause()

The semantics of the names "pause" and "resume" are a bit weird, but the
important thing is that this corrects an API change from 0.4 -> 0.6
which made it impossible to read from stdin multiple times, without
knowing when it might end up being closed.  If no one has it open, this
lets the process die naturally.

LGTM'd by @ry

4 files changed, 27 insertions, 6 deletions

diff --git a/src/handle_wrap.cc b/src/handle_wrap.cc
index 6e07643893c..5b6594a3a90 100644
--- a/src/handle_wrap.cc
+++ b/src/handle_wrap.cc
@@ -64,8 +64,10 @@ Handle<Value> HandleWrap::Unref(const Arguments& args) {
 
   UNWRAP
 
-  // Calling this function twice should never happen.
-  assert(wrap->unref == false);
+  // Calling unnecessarily is a no-op
+  if (wrap->unref) {
+    return v8::Undefined();
+  }
 
   wrap->unref = true;
   uv_unref(uv_default_loop());
@@ -74,6 +76,24 @@ Handle<Value> HandleWrap::Unref(const Arguments& args) {
 }
 
 
+// Adds a reference to keep uv alive because of this thing.
+Handle<Value> HandleWrap::Ref(const Arguments& args) {
+  HandleScope scope;
+
+  UNWRAP
+
+  // Calling multiple times is a no-op
+  if (!wrap->unref) {
+    return v8::Undefined();
+  }
+
+  wrap->unref = false;
+  uv_ref(uv_default_loop());
+
+  return v8::Undefined();
+}
+
+
 Handle<Value> HandleWrap::Close(const Arguments& args) {
   HandleScope scope;
 
@@ -82,10 +102,8 @@ Handle<Value> HandleWrap::Close(const Arguments& args) {
   assert(!wrap->object_.IsEmpty());
   uv_close(wrap->handle__, OnClose);
 
-  if (wrap->unref) {
-    uv_ref(uv_default_loop());
-    wrap->unref = false;
-  }
+
+  HandleWrap::Ref(args);
 
   wrap->StateChange();
 
diff --git a/src/handle_wrap.h b/src/handle_wrap.h
index fc6d623ac65..b9cf31e8eb1 100644
--- a/src/handle_wrap.h
+++ b/src/handle_wrap.h
@@ -49,6 +49,7 @@ class HandleWrap {
     static void Initialize(v8::Handle<v8::Object> target);
     static v8::Handle<v8::Value> Close(const v8::Arguments& args);
     static v8::Handle<v8::Value> Unref(const v8::Arguments& args);
+    static v8::Handle<v8::Value> Ref(const v8::Arguments& args);
 
   protected:
     HandleWrap(v8::Handle<v8::Object> object, uv_handle_t* handle);
diff --git a/src/pipe_wrap.cc b/src/pipe_wrap.cc
index a2a4203a804..1870837bcae 100644
--- a/src/pipe_wrap.cc
+++ b/src/pipe_wrap.cc
@@ -85,6 +85,7 @@ void PipeWrap::Initialize(Handle<Object> target) {
 
   NODE_SET_PROTOTYPE_METHOD(t, "close", HandleWrap::Close);
   NODE_SET_PROTOTYPE_METHOD(t, "unref", HandleWrap::Unref);
+  NODE_SET_PROTOTYPE_METHOD(t, "ref", HandleWrap::Ref);
 
   NODE_SET_PROTOTYPE_METHOD(t, "readStart", StreamWrap::ReadStart);
   NODE_SET_PROTOTYPE_METHOD(t, "readStop", StreamWrap::ReadStop);
diff --git a/src/tty_wrap.cc b/src/tty_wrap.cc
index b46e6c4e1fd..486c2a70b4b 100644
--- a/src/tty_wrap.cc
+++ b/src/tty_wrap.cc
@@ -69,6 +69,7 @@ class TTYWrap : StreamWrap {
 
     NODE_SET_PROTOTYPE_METHOD(t, "close", HandleWrap::Close);
     NODE_SET_PROTOTYPE_METHOD(t, "unref", HandleWrap::Unref);
+    NODE_SET_PROTOTYPE_METHOD(t, "ref", HandleWrap::Ref);
 
     NODE_SET_PROTOTYPE_METHOD(t, "readStart", StreamWrap::ReadStart);
     NODE_SET_PROTOTYPE_METHOD(t, "readStop", StreamWrap::ReadStop);