From fcd29c8a671089174ed8993cef9b456d78bdc7a6 Mon Sep 17 00:00:00 2001
From: Jeremy Elbourn <jelbourn@gmail.com>
Date: Wed, 9 Nov 2016 16:29:51 -0800
Subject: [PATCH] fix(snackbar): snacksbars sometimes don't get removed (#1795)

---
 src/lib/snack-bar/snack-bar.spec.ts | 17 +++++++++++++++++
 src/lib/snack-bar/snack-bar.ts      |  5 ++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/lib/snack-bar/snack-bar.spec.ts b/src/lib/snack-bar/snack-bar.spec.ts
index 90fced2e3a1f..778440b0cdc3 100644
--- a/src/lib/snack-bar/snack-bar.spec.ts
+++ b/src/lib/snack-bar/snack-bar.spec.ts
@@ -219,6 +219,23 @@ describe('MdSnackBar', () => {
       });
     });
   }));
+
+  it('should remove past snackbars when opening new snackbars', async(() => {
+    snackBar.open('First snackbar');
+    viewContainerFixture.detectChanges();
+
+    snackBar.open('Second snackbar');
+    viewContainerFixture.detectChanges();
+
+    viewContainerFixture.whenStable().then(() => {
+      snackBar.open('Third snackbar');
+      viewContainerFixture.detectChanges();
+
+      viewContainerFixture.whenStable().then(() => {
+        expect(overlayContainerElement.textContent.trim()).toBe('Third snackbar');
+      });
+    });
+  }));
 });
 
 @Directive({selector: 'dir-with-view-container'})
diff --git a/src/lib/snack-bar/snack-bar.ts b/src/lib/snack-bar/snack-bar.ts
index 8ba710d8665c..23b63158c37b 100644
--- a/src/lib/snack-bar/snack-bar.ts
+++ b/src/lib/snack-bar/snack-bar.ts
@@ -48,7 +48,10 @@ export class MdSnackBar {
 
     // When the snackbar is dismissed, clear the reference to it.
     snackBarRef.afterDismissed().subscribe(() => {
-      this._snackBarRef = null;
+      // Clear the snackbar ref if it hasn't already been replaced by a newer snackbar.
+      if (this._snackBarRef == snackBarRef) {
+        this._snackBarRef = null;
+      }
     });
 
     // If a snack bar is already in view, dismiss it and enter the new snack bar after exit