From 0526689fdec1a34c0aa3adf93dcbfc7ec601b07a Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@users.noreply.github.com>
Date: Wed, 23 Aug 2017 02:43:49 +0200
Subject: [PATCH] fix(select): error if triggerValue is accessed from an empty
 select (#6575)

---
 src/lib/select/select.spec.ts | 7 +++++++
 src/lib/select/select.ts      | 6 +++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/lib/select/select.spec.ts b/src/lib/select/select.spec.ts
index 5c12c95b730..cdab73d963b 100644
--- a/src/lib/select/select.spec.ts
+++ b/src/lib/select/select.spec.ts
@@ -2184,6 +2184,13 @@ describe('MdSelect', () => {
         expect(() => fixture.detectChanges()).not.toThrow();
       }));
 
+
+    it('should not throw when the triggerValue is accessed when there is no selected value', () => {
+      const fixture = TestBed.createComponent(BasicSelect);
+      fixture.detectChanges();
+
+      expect(() => fixture.componentInstance.select.triggerValue).not.toThrow();
+    });
   });
 
   describe('change event', () => {
diff --git a/src/lib/select/select.ts b/src/lib/select/select.ts
index 95d5d282c06..fd76f0b7805 100644
--- a/src/lib/select/select.ts
+++ b/src/lib/select/select.ts
@@ -568,8 +568,12 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
 
   /** The value displayed in the trigger. */
   get triggerValue(): string {
+    if (!this._selectionModel || this._selectionModel.isEmpty()) {
+      return '';
+    }
+
     if (this._multiple) {
-      let selectedOptions = this._selectionModel.selected.map(option => option.viewValue);
+      const selectedOptions = this._selectionModel.selected.map(option => option.viewValue);
 
       if (this._isRtl()) {
         selectedOptions.reverse();