fix(panel/common): fix for query letters when importing old dashboards, fixes #2943

public/app/features/dashboard/dashboardSrv.js

@@ -328,11 +328,22 @@ function (angular, $, kbn, _, moment) {
         }
       }
 
-      if (oldVersion < 7 && old.nav && old.nav.length) {
+      if (oldVersion < 7) {
+        if (old.nav && old.nav.length) {
           this.timepicker = old.nav[0];
           delete this.nav;
         }
 
+        // ensure query refIds
+        panelUpgrades.push(function(panel) {
+          _.each(panel.targets, function(target) {
+            if (!target.refId) {
+              target.refId = this.getNextQueryLetter(panel);
+            }
+          }, this);
+        });
+      }
+
       if (panelUpgrades.length === 0) {
         return;
       }
@@ -341,7 +352,7 @@ function (angular, $, kbn, _, moment) {
         var row = this.rows[i];
         for (j = 0; j < row.panels.length; j++) {
           for (k = 0; k < panelUpgrades.length; k++) {
-            panelUpgrades[k](row.panels[j]);
+            panelUpgrades[k].call(this, row.panels[j]);
           }
         }
       }

public/test/specs/dashboardSrv-specs.js

@@ -152,7 +152,10 @@ define([
           rows: [
             {
               panels: [
-                {type: 'graphite', legend: true, aliasYAxis: { test: 2 }, grid: { min: 1, max: 10 }}
+                {
+                  type: 'graphite', legend: true, aliasYAxis: { test: 2 }, grid: { min: 1, max: 10 },
+                  targets: [{refId: 'A'}, {}],
+                }
               ]
             }
           ]
@@ -178,6 +181,10 @@ define([
         expect(graph.type).to.be('graph');
       });
 
+      it('queries without refId should get it', function() {
+        expect(graph.targets[1].refId).to.be('B');
+      });
+
       it('update legend setting', function() {
         expect(graph.legend.show).to.be(true);
       });