From 3b7f0f12d4c3ffb42c1e31dcbed6f52721da1f6c Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@users.noreply.github.com>
Date: Mon, 27 Aug 2018 18:58:39 +0200
Subject: [PATCH] fix(select): pointing to non-existent element via
 aria-labelledby (#12411)

Fixes `mat-select` referring to an element that doesn't exist, through `aria-labelledby`, if the select is inside a form field that doesn't have a label.

Fixes #12405.
---
 src/lib/select/select.spec.ts | 11 +++++++++++
 src/lib/select/select.ts      |  3 ++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/lib/select/select.spec.ts b/src/lib/select/select.spec.ts
index 80510998722..2f8a152aa0b 100644
--- a/src/lib/select/select.spec.ts
+++ b/src/lib/select/select.spec.ts
@@ -126,6 +126,7 @@ describe('MatSelect', () => {
         SelectWithGroups,
         SelectWithGroupsAndNgContainer,
         SelectWithFormFieldLabel,
+        SelectWithChangeEvent,
       ]);
     }));
 
@@ -255,6 +256,16 @@ describe('MatSelect', () => {
           expect(select.getAttribute('aria-labelledby')).toBeFalsy();
         });
 
+        it('should not set `aria-labelledby` if there is no form field label', () => {
+          fixture.destroy();
+
+          const labelFixture = TestBed.createComponent(SelectWithChangeEvent);
+          labelFixture.detectChanges();
+          select = labelFixture.debugElement.query(By.css('mat-select')).nativeElement;
+
+          expect(select.getAttribute('aria-labelledby')).toBeFalsy();
+        });
+
         it('should select options via the UP/DOWN arrow keys on a closed select', fakeAsync(() => {
           const formControl = fixture.componentInstance.control;
           const options = fixture.componentInstance.options.toArray();
diff --git a/src/lib/select/select.ts b/src/lib/select/select.ts
index b51ffcb7a13..775569e4706 100644
--- a/src/lib/select/select.ts
+++ b/src/lib/select/select.ts
@@ -1065,7 +1065,8 @@ export class MatSelect extends _MatSelectMixinBase implements AfterContentInit,
 
     // Note: we use `_getAriaLabel` here, because we want to check whether there's a
     // computed label. `this.ariaLabel` is only the user-specified label.
-    if (!this._parentFormField || this._getAriaLabel()) {
+    if (!this._parentFormField || !this._parentFormField._hasFloatingLabel() ||
+      this._getAriaLabel()) {
       return null;
     }