Merge lp:~ahayzen/music-app/startup-model-console-warning into lp:music-app/remix

[Andrew Hayzen]

* Fix for console error on startup

* Fix for console error on startup

[Ubuntu Phone Apps Jenkins Bot (ubuntu-phone-apps-jenkins-bot)]

PASSED: Continuous integration, rev:832
http://91.189.93.70:8080/job/music-app-ci/1276/
Executed test runs:
    SUCCESS: http://91.189.93.70:8080/job/generic-mediumtests-vivid/1026
        deb: http://91.189.93.70:8080/job/generic-mediumtests-vivid/1026/artifact/work/output/*zip*/output.zip
    SUCCESS: http://91.189.93.70:8080/job/music-app-vivid-amd64-ci/128

Click here to trigger a rebuild:
http://91.189.93.70:8080/job/music-app-ci/1276/rebuild

review: Approve (continuous-integration)

[Victor Thompson (vthompson)]

What console error does this prevent?

review: Needs Information

[Andrew Hayzen (ahayzen)]

/app/music-app.qml:1320: TypeError: Cannot read property 'model' of null

[Victor Thompson (vthompson)]

lgtm!

review: Approve

=== modified file 'music-app.qml'
--- music-app.qml	2015-02-04 00:29:37 +0000
+++ music-app.qml	2015-02-05 22:41:09 +0000
@@ -1257,7 +1257,7 @@
             // Set the models in the tab to allow/disallow loading
             function allowLoading(tabToLoad, state)
             {
-                if (tabToLoad !== undefined && tabToLoad.model !== undefined)
+                if (tabToLoad && tabToLoad.model !== undefined)
                 {
                     for (var i=0; i < tabToLoad.model.length; i++)
                     {
@@ -1268,21 +1268,24 @@
 
             function ensurePopulated(selectedTab)
             {
-                allowLoading(selectedTab, true);  // allow loading of the models
-
-                if (!selectedTab.populated && !selectedTab.loading && loadedUI) {
-                    loading.visible = true
-                    selectedTab.loading = true
-
-                    if (selectedTab.loader !== undefined)
-                    {
-                        for (var i=0; i < selectedTab.loader.length; i++)
+                if (selectedTab) {  // check not null or undefined
+                    allowLoading(selectedTab, true);  // allow loading of the models
+
+                    if (!selectedTab.populated && !selectedTab.loading && loadedUI) {
+                        loading.visible = true
+                        selectedTab.loading = true
+
+                        if (selectedTab.loader !== undefined)
                         {
-                            selectedTab.loader[i]();
+                            for (var i=0; i < selectedTab.loader.length; i++)
+                            {
+                                selectedTab.loader[i]();
+                            }
                         }
                     }
+
+                    loading.visible = selectedTab.loading || !selectedTab.populated
                 }
-                loading.visible = selectedTab.loading || !selectedTab.populated
             }
 
             function pushNowPlaying()