Fix up spec version handling

Author: headius

ext/java/org/jruby/ext/psych/PsychEmitter.java

@@ -140,13 +140,18 @@ public IRubyObject start_document(ThreadContext context, IRubyObject _version, I
         TypeConverter.checkType(context, _version, arrayClass);
 
         RubyArray versionAry = _version.convertToArray();
+        Optional<SpecVersion> specVersion;
         if (versionAry.size() == 2) {
             int versionInt0 = versionAry.eltInternal(0).convertToInteger().getIntValue();
             int versionInt1 = versionAry.eltInternal(1).convertToInteger().getIntValue();
 
-            if (versionInt0 != 1 || versionInt1 != 2) {
-//                throw runtime.newArgumentError("invalid YAML version: " + versionAry);
+            if (versionInt0 != 1) {
+                throw runtime.newArgumentError("invalid YAML version: " + versionAry);
             }
+
+            specVersion = Optional.of(new SpecVersion(versionInt0, versionInt1));
+        } else {
+            specVersion = Optional.empty();
         }
 
         Map<String, String> tagsMap = new HashMap<>();
@@ -171,7 +176,7 @@ public IRubyObject start_document(ThreadContext context, IRubyObject _version, I
             }
         }
 
-        DocumentStartEvent event = new DocumentStartEvent(!implicitBool, Optional.empty(), tagsMap, NULL_MARK, NULL_MARK);
+        DocumentStartEvent event = new DocumentStartEvent(!implicitBool, specVersion, tagsMap, NULL_MARK, NULL_MARK);
         emit(context, event);
         return this;
     }

ext/java/org/jruby/ext/psych/PsychParser.java

@@ -305,10 +305,11 @@ public IRubyObject parse(ThreadContext context, IRubyObject handler, IRubyObject
 
     private void handleDocumentStart(ThreadContext context, DocumentStartEvent dse, IRubyObject handler) {
         Ruby runtime = context.runtime;
-        SpecVersion _version = dse.getSpecVersion().orElse(new SpecVersion(1, 2));
-        IRubyObject version = _version == null ?
-            RubyArray.newArray(runtime) :
-            RubyArray.newArray(runtime, runtime.newFixnum(_version.getMajor()), runtime.newFixnum(_version.getMinor()));
+
+        Optional<SpecVersion> specVersion = dse.getSpecVersion();
+        IRubyObject version = specVersion.isPresent() ?
+                RubyArray.newArray(runtime, runtime.newFixnum(specVersion.get().getMajor()), runtime.newFixnum(specVersion.get().getMinor())) :
+                RubyArray.newEmptyArray(runtime);
 
         Map<String, String> tagsMap = dse.getTags();
         RubyArray tags = RubyArray.newArray(runtime);