Fix FasterXML#123

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -14,6 +14,7 @@ Modules:
  (reported by jflefebvre06@github)
 #122: (csv) `readValues(null)` causes infinite loop
  (reported by andyeko@github) 
+#123: (yaml) YAML Anchor, reference fails with simple example
 
 2.9.8 (15-Dec-2018)
 

yaml/src/main/java/com/fasterxml/jackson/dataformat/yaml/YAMLParser.java

@@ -366,9 +366,9 @@ public JsonToken nextToken() throws IOException
                 return (_currToken = null);
             }
             _lastEvent = evt;
-
-            // One complication: field names are only inferred from the
-            // fact that we are in Object context...
+            // One complication: field names are only inferred from the fact that we are
+            // in Object context; they are just ScalarEvents (but separate and NOT just tagged
+            // on values)
             if (_parsingContext.inObject()) {
                 if (_currToken != JsonToken.FIELD_NAME) {
                     if (!evt.is(Event.ID.Scalar)) {
@@ -383,11 +383,20 @@ public JsonToken nextToken() throws IOException
                         }
                         _reportError("Expected a field name (Scalar value in YAML), got this instead: "+evt);
                     }
-                    ScalarEvent scalar = (ScalarEvent) evt;
-                    String name = scalar.getValue();
+                    // 20-Feb-2019, tatu: [dataformats-text#123] Looks like YAML exposes Anchor for Object at point
+                    //   where we return START_OBJECT (which makes sense), but, alas, Jackson expects that at point
+                    //   after first FIELD_NAME. So we will need to defer clearing of the anchor slightly,
+                    //   just for the very first entry; and only if no anchor for name found.
+                    //  ... not even 100% sure this is correct, or robust, but does appear to work for specific
+                    //  test case given.
+                    final ScalarEvent scalar = (ScalarEvent) evt;
+                    final String newAnchor = scalar.getAnchor();
+                    if ((newAnchor != null) || (_currToken != JsonToken.START_OBJECT)) {
+                        _currentAnchor = scalar.getAnchor();
+                    }
+                    final String name = scalar.getValue();
                     _currentFieldName = name;
                     _parsingContext.setCurrentName(name);
-                    _currentAnchor = scalar.getAnchor();
                     return (_currToken = JsonToken.FIELD_NAME);
                 }
             }
@@ -856,10 +865,8 @@ public String getTypeId() throws IOException, JsonGenerationException
             return null;
         }
         if (tag != null) {
-            /* 04-Aug-2013, tatu: Looks like YAML parser's expose these in...
-             *   somewhat exotic ways sometimes. So let's prepare to peel off
-             *   some wrappings:
-             */
+            // 04-Aug-2013, tatu: Looks like YAML parser's expose these in... somewhat exotic
+            //   ways sometimes. So let's prepare to peel off some wrappings:
             while (tag.startsWith("!")) {
                 tag = tag.substring(1);
             }

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/failing/ObjectIdTest.java renamed to yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/failing/ObjectIdWithTreeTest.java

@@ -10,7 +10,7 @@
  * Although native Object Ids work in general, Tree Model currently
  * has issues with it (see [dataformat-yaml#24])
  */
-public class ObjectIdTest extends ModuleTestBase
+public class ObjectIdWithTreeTest extends ModuleTestBase
 {
     @JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class, property="@id")
     static class Node

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/misc/ObjectId123Test.java

@@ -0,0 +1,40 @@
+package com.fasterxml.jackson.dataformat.yaml.misc;
+
+import com.fasterxml.jackson.annotation.*;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.*;
+
+//for [dataformats-text#123], problem with YAML, Object Ids
+public class ObjectId123Test extends ModuleTestBase
+{
+    private final ObjectMapper MAPPER = newObjectMapper();
+    
+    public void testObjectIdUsingNative() throws Exception
+    {
+        final String YAML_CONTENT =
+                "foo: &foo1\n" +
+                "  value: bar\n" +
+                "boo: *foo1\n";
+        ScratchModel result = MAPPER.readValue(YAML_CONTENT, ScratchModel.class);
+        assertNotNull(result);
+        assertNotNull(result.foo);
+        assertNotNull(result. boo);
+        assertSame(result.foo, result.boo);
+    }
+
+    static class ScratchModel {
+        public StringHolder foo;
+        public StringHolder boo;
+    }
+
+//    @JsonIdentityInfo(generator = ObjectIdGenerators.None.class)
+    @JsonIdentityInfo(generator = ObjectIdGenerators.StringIdGenerator.class)
+    static class StringHolder {
+        public String value;
+
+        @Override
+        public String toString() {
+            return value;
+        }
+    }
+}

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/failing/ObjectId63Test.java renamed to yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/misc/ObjectId63Test.java

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.dataformat.yaml.failing;
+package com.fasterxml.jackson.dataformat.yaml.misc;
 
 import com.fasterxml.jackson.annotation.JsonIdentityInfo;
 import com.fasterxml.jackson.annotation.ObjectIdGenerators;