[index patterns] Fallback to id if title does not exist (#14302)

* [index patterns] Fallback to id if title does not exist

* [tests] browser index patterns should always have id and title

* [tests] add regression test for no saved title

src/ui/public/index_patterns/__tests__/_index_pattern.js

@@ -103,11 +103,20 @@ describe('index pattern', function () {
         expect(indexPattern).to.have.property('toString');
         expect(indexPattern).to.have.property('toJSON');
         expect(indexPattern).to.have.property('save');
+        expect(indexPattern).to.have.property('title');
+        expect(indexPattern).to.have.property('id');
 
         // properties
         expect(indexPattern).to.have.property('fields');
       });
     });
+
+    it('should have a title when there is no saved title', function () {
+      const id = 'foo';
+      return create(id, {}).then(function (indexPattern) {
+        expect(indexPattern.title).to.be(id);
+      });
+    });
   });
 
   describe('init', function () {

src/ui/public/index_patterns/_index_pattern.js

@@ -89,6 +89,12 @@ export function IndexPatternProvider(Private, $http, config, kbnIndex, Promise,
     // give index pattern all of the values in _source
     _.assign(indexPattern, response._source);
 
+    // older kibana indices reference the index pattern by _id and may not have the pattern
+    // saved in title
+    // if the title doesn't exist, it's an old format and we can use the id instead
+    if (!indexPattern.title) {
+      indexPattern.title = indexPattern.id;
+    }
     return indexFields(indexPattern);
   }