fix(virtualRepeat): Recover from scroll events that occur when hidden

Fixes #5448.

comment

Author: kseamon

src/components/virtualRepeat/virtual-repeater.js

@@ -197,6 +197,11 @@ VirtualRepeatContainerController.prototype.updateSize = function() {
       ? this.$element[0].clientWidth
       : this.$element[0].clientHeight;
 
+  // Recheck the scroll position after updating the size. This resolves
+  // problems that can result if the scroll position was measured while the
+  // element was display: none or detached from the document.
+  this.handleScroll_();
+
   this.repeater && this.repeater.containerUpdated();
 };
 

src/components/virtualRepeat/virtual-repeater.spec.js

@@ -580,17 +580,25 @@ describe('<md-virtual-repeat>', function() {
     expect(offsetter.children().length).toBe(43);
   });
 
-  it('should recheck container size on $md-resize scope event', function() {
+  it('should recheck container size and scroll position on $md-resize scope ' +
+      'event', function() {
     scope.items = createItems(100);
     createRepeater();
     // Expect 13 children (10 + 3 extra).
     expect(offsetter.children().length).toBe(13);
 
+    container.css('height', '300px');
+    scope.$parent.$broadcast('$md-resize');
+
+    // Expect 33 children (30 + 3 extra).
+    expect(offsetter.children().length).toBe(33);
+
     container.css('height', '400px');
+    scroller[0].scrollTop = 20;
     scope.$parent.$broadcast('$md-resize');
 
-    // Expect 43 children (40 + 3 extra).
-    expect(offsetter.children().length).toBe(43);
+    // Expect 43 children (40 + 5 extra).
+    expect(offsetter.children().length).toBe(45);
   });
 
   it('should shrink when initial results require shrinking', inject(function() {