Disallowed a plain scalar with just a dash

src/exp.h

@@ -137,7 +137,7 @@ namespace YAML
 		// . In the block context - ? : must be not be followed with a space.
 		// . In the flow context ? is illegal and : and - must not be followed with a space.
 		inline const RegEx& PlainScalar() {
-			static const RegEx e = !(BlankOrBreak() || RegEx(",[]{}#&*!|>\'\"%@`", REGEX_OR) || (RegEx("-?:", REGEX_OR) + Blank()));
+			static const RegEx e = !(BlankOrBreak() || RegEx(",[]{}#&*!|>\'\"%@`", REGEX_OR) || (RegEx("-?:", REGEX_OR) + (BlankOrBreak() || RegEx())));
 			return e;
 		}
 		inline const RegEx& PlainScalarInFlow() {

test/emittertests.cpp

@@ -892,6 +892,15 @@ namespace Test
             out << YAML::EndSeq;
             desiredOutput = "- 1.23\n- 3.14159";
         }
+        
+        void DashInBlockContext(YAML::Emitter& out, std::string& desiredOutput)
+        {
+            out << YAML::BeginMap;
+            out << YAML::Key << "key" << YAML::Value << "-";
+            out << YAML::EndMap;
+            desiredOutput = "key: \"-\"";
+        }
+        
         ////////////////////////////////////////////////////////////////////////////////////////////////////////
 		// incorrect emitting
 		
@@ -995,7 +1004,7 @@ namespace Test
 					YAML::Node node;
 					parser.GetNextDocument(node);
 #else
-					// Parse with the new API
+//                    YAML::Node node = YAML::Load(output);
 #endif
 					
 					passed++;
@@ -1113,6 +1122,7 @@ namespace Test
 		RunEmitterTest(&Emitter::SingleChar, "single char", passed, total);
 		RunEmitterTest(&Emitter::DefaultPrecision, "default precision", passed, total);
 		RunEmitterTest(&Emitter::SetPrecision, "set precision", passed, total);
+		RunEmitterTest(&Emitter::DashInBlockContext, "dash in block context", passed, total);
 		
 		RunEmitterErrorTest(&Emitter::ExtraEndSeq, "extra EndSeq", passed, total);
 		RunEmitterErrorTest(&Emitter::ExtraEndMap, "extra EndMap", passed, total);