fixed broken serialization of duplicated entries in sequences

For example, with the following code

```
var obj = { test: 'canary' };
var array = [ 0, 1 ];
var arrayWithRefs = [ obj, obj, array, array ];
```

`arrayWithRefs` was serialized as

```
- &ref_0test: canary
- *ref0
- &ref_1- 0
  - 1
- *ref1
```

which is incorrect.

Author: vogelsgesang

lib/js-yaml.js

@@ -27,7 +27,7 @@ module.exports.dump                = dumper.dump;
 module.exports.safeDump            = dumper.safeDump;
 module.exports.YAMLException       = require('./js-yaml/exception');
 
-// Deprecared schema names from JS-YAML 2.0.x
+// Deprecated schema names from JS-YAML 2.0.x
 module.exports.MINIMAL_SCHEMA = require('./js-yaml/schema/failsafe');
 module.exports.SAFE_SCHEMA    = require('./js-yaml/schema/default_safe');
 module.exports.DEFAULT_SCHEMA = require('./js-yaml/schema/default_full');

lib/js-yaml/dumper.js

@@ -715,10 +715,6 @@ function writeNode(state, level, object, block, compact, iskey) {
     block = (0 > state.flowLevel || state.flowLevel > level);
   }
 
-  if ((null !== state.tag && '?' !== state.tag) || (2 !== state.indent && level > 0)) {
-    compact = false;
-  }
-
   var objectOrArray = '[object Object]' === type || '[object Array]' === type,
       duplicateIndex,
       duplicate;
@@ -728,6 +724,10 @@ function writeNode(state, level, object, block, compact, iskey) {
     duplicate = duplicateIndex !== -1;
   }
 
+  if ((null !== state.tag && '?' !== state.tag) || duplicate || (2 !== state.indent && level > 0)) {
+    compact = false;
+  }
+
   if (duplicate && state.usedDuplicates[duplicateIndex]) {
     state.dump = '*ref_' + duplicateIndex;
   } else {
@@ -738,7 +738,7 @@ function writeNode(state, level, object, block, compact, iskey) {
       if (block && (0 !== Object.keys(state.dump).length)) {
         writeBlockMapping(state, level, state.dump, compact);
         if (duplicate) {
-          state.dump = '&ref_' + duplicateIndex + (0 === level ? '\n' : '') + state.dump;
+          state.dump = '&ref_' + duplicateIndex + state.dump;
         }
       } else {
         writeFlowMapping(state, level, state.dump);
@@ -750,7 +750,7 @@ function writeNode(state, level, object, block, compact, iskey) {
       if (block && (0 !== state.dump.length)) {
         writeBlockSequence(state, level, state.dump, compact);
         if (duplicate) {
-          state.dump = '&ref_' + duplicateIndex + (0 === level ? '\n' : '') + state.dump;
+          state.dump = '&ref_' + duplicateIndex + state.dump;
         }
       } else {
         writeFlowSequence(state, level, state.dump);

test/issues/0205.js

@@ -0,0 +1,27 @@
+'use strict';
+
+
+var assert = require('assert');
+var yaml   = require('../../');
+
+
+test('Duplicated objects within array', function () {
+  var obj = { test: 'canary' };
+  var arrayWithRefs = [ obj, obj ];
+
+  var obtained = yaml.load(yaml.dump(arrayWithRefs));
+
+  assert.equal(obtained[0].test, 'canary');
+  assert.equal(obtained[0], obtained[1]);
+});
+
+test('Duplicated arrays within array', function () {
+  var array = [ 0, 1 ];
+  var arrayWithRefs = [ array, array ];
+
+  var obtained = yaml.load(yaml.dump(arrayWithRefs));
+
+  assert.equal(obtained[0][0], 0);
+  assert.equal(obtained[0][1], 1);
+  assert.equal(obtained[0], obtained[1]);
+});