Some small changes as a result of using a static analyzer (#643)

* Removed an expression which is always true
* The second expression (ch is space) is removed because the first one contains space 0x20
* nextEmptyLine is always false so it is removed from the expression

src/emitter.cpp

@@ -285,10 +285,8 @@ void Emitter::PrepareTopNode(EmitterNodeType::value child) {
   if (child == EmitterNodeType::NoType)
     return;
 
-  if (m_pState->CurGroupChildCount() > 0 && m_stream.col() > 0) {
+  if (m_pState->CurGroupChildCount() > 0 && m_stream.col() > 0)
-    if (child != EmitterNodeType::NoType)
     EmitBeginDoc();
-  }
 
   switch (child) {
     case EmitterNodeType::NoType:

src/emitterutils.cpp

@@ -382,7 +382,7 @@ bool WriteChar(ostream_wrapper& out, char ch) {
     out << "\"\\b\"";
   } else if (ch == '\\') {
     out << "\"\\\\\"";
-  } else if ((0x20 <= ch && ch <= 0x7e) || ch == ' ') {
+  } else if (0x20 <= ch && ch <= 0x7e) {
     out << "\"" << ch << "\"";
   } else {
     out << "\"";

src/scanscalar.cpp

@@ -183,7 +183,7 @@ std::string ScanScalar(Stream& INPUT, ScanScalarParams& params) {
         case FOLD_FLOW:
           if (nextEmptyLine) {
             scalar += "\n";
-          } else if (!emptyLine && !nextEmptyLine && !escapedNewline) {
+          } else if (!emptyLine && !escapedNewline) {
             scalar += " ";
           }
           break;