Flow + Newline + EmptyMap bug

[MidoriYakumo]

Add following test case:

TEST_F(EmitterTest, FlowNewlineEmpty)
{
        out << YAML::BeginMap;
        out << YAML::Key << "foo";
        out << YAML::Value << YAML::Flow << YAML::BeginMap << YAML::Newline << YAML::EndMap;
        out << YAML::EndMap;

        ExpectEmit("foo: {\n  }\n");
}

but result is "foo: {\n {}\n"

[MidoriYakumo]

Can be fixed with diff:

diff --git a/src/emitter.cpp b/src/emitter.cpp
index 016beb1..334d0d9 100644
--- a/src/emitter.cpp
+++ b/src/emitter.cpp
@@ -198,6 +198,7 @@ void Emitter::EmitEndSeq() {
   if (!good())
     return;
 
+  bool need_left_brace = !m_pState->HasBegunNode() || m_stream.comment();
   if (m_pState->CurGroupChildCount() == 0)
     m_pState->ForceFlow();
 
@@ -205,7 +206,7 @@ void Emitter::EmitEndSeq() {
     if (m_stream.comment())
       m_stream << "\n";
     m_stream << IndentTo(m_pState->CurIndent());
-    if (m_pState->CurGroupChildCount() == 0)
+    if (m_pState->CurGroupChildCount() == 0 && need_left_brace)
       m_stream << "[";
     m_stream << "]";
   }
@@ -228,6 +229,7 @@ void Emitter::EmitEndMap() {
   if (!good())
     return;
 
+  bool need_left_brace = !m_pState->HasBegunNode() || m_stream.comment();
   if (m_pState->CurGroupChildCount() == 0)
     m_pState->ForceFlow();
 
@@ -235,7 +237,7 @@ void Emitter::EmitEndMap() {
     if (m_stream.comment())
       m_stream << "\n";
     m_stream << IndentTo(m_pState->CurIndent());
-    if (m_pState->CurGroupChildCount() == 0)
+    if (m_pState->CurGroupChildCount() == 0 && need_left_brace)
       m_stream << "{";
     m_stream << "}";
   }
diff --git a/test/integration/emitter_test.cpp b/test/integration/emitter_test.cpp
index 3a5783b..8ae2452 100644
--- a/test/integration/emitter_test.cpp
+++ b/test/integration/emitter_test.cpp
@@ -1075,5 +1075,15 @@ TEST_F(EmitterErrorTest, InvalidAlias) {
 
   ExpectEmitError(ErrorMsg::INVALID_ALIAS);
 }
+
+TEST_F(EmitterTest, FlowEmptyNewlineMap)
+{
+  out << YAML::BeginMap;
+  out << YAML::Key << "foo";
+  out << YAML::Value << YAML::Flow << YAML::BeginMap << YAML::Newline << YAML::EndMap;
+  out << YAML::EndMap;
+
+  ExpectEmit("foo: {\n  }");
+}
 }  // namespace
 }  // namespace YAML

[dota17]

Fixed by #921.