From 8f1fce1cb9e9a3dd0271b78260e8ba3010449743 Mon Sep 17 00:00:00 2001
From: "REDMOND\\chiechan" <chiechan@microsoft.com>
Date: Mon, 7 May 2018 19:02:57 -0700
Subject: [PATCH 1/4] added fix for alt + down on menu for a menu button and
 not just split button

---
 .../src/components/Button/BaseButton.tsx               | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
index 2363f38db1e71f..3b554311f5aa0b 100644
--- a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
+++ b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
@@ -450,7 +450,7 @@ export class BaseButton extends BaseComponent<IBaseButtonProps, IBaseButtonState
 
   private _openMenu = (shouldFocusOnContainer?: boolean): void => {
     if (this.props.menuProps) {
-      const menuProps = {...this.props.menuProps, shouldFocusOnContainer: shouldFocusOnContainer };
+      const menuProps = { ...this.props.menuProps, shouldFocusOnContainer: shouldFocusOnContainer };
       if (this.props.persistMenu) {
         menuProps.hidden = false;
       }
@@ -679,12 +679,8 @@ export class BaseButton extends BaseComponent<IBaseButtonProps, IBaseButtonState
   private _isValidMenuOpenKey(ev: React.KeyboardEvent<HTMLDivElement | HTMLAnchorElement | HTMLButtonElement>): boolean {
     if (this.props.menuTriggerKeyCode) {
       return ev.which === this.props.menuTriggerKeyCode;
-    } else {
-      if (this._isSplitButton) {
-        return ev.which === KeyCodes.down && (ev.altKey || ev.metaKey);
-      } else {
-        return ev.which === KeyCodes.enter;
-      }
+    } else if (this.props.menuProps) {
+      return ev.which === KeyCodes.down && (ev.altKey || ev.metaKey);
     }
   }
 

From fda1afecbcdc27407665ce8cf2f638bccff08e17 Mon Sep 17 00:00:00 2001
From: "REDMOND\\chiechan" <chiechan@microsoft.com>
Date: Mon, 7 May 2018 19:09:26 -0700
Subject: [PATCH 2/4] added change file; added comment

---
 .../master_2018-05-08-02-09.json                      | 11 +++++++++++
 .../src/components/Button/BaseButton.tsx              |  3 +++
 2 files changed, 14 insertions(+)
 create mode 100644 common/changes/office-ui-fabric-react/master_2018-05-08-02-09.json

diff --git a/common/changes/office-ui-fabric-react/master_2018-05-08-02-09.json b/common/changes/office-ui-fabric-react/master_2018-05-08-02-09.json
new file mode 100644
index 00000000000000..c131957538deb1
--- /dev/null
+++ b/common/changes/office-ui-fabric-react/master_2018-05-08-02-09.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "BaseButton: Allow Alt + Down on menu buttons to open the menu",
+      "type": "patch"
+    }
+  ],
+  "packageName": "office-ui-fabric-react",
+  "email": "chiechan@microsoft.com"
+}
\ No newline at end of file
diff --git a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
index 3b554311f5aa0b..46eeb333f4182c 100644
--- a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
+++ b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
@@ -639,6 +639,9 @@ export class BaseButton extends BaseComponent<IBaseButtonProps, IBaseButtonState
       ev.preventDefault();
       ev.stopPropagation();
     }
+
+    // Note: When enter is pressed, we will let the event continue to propagate
+    // to trigger the onClick event on the button
   }
 
   private _onTouchStart: () => void = () => {

From 8919015418481d85d63b87de921365f08640ccf8 Mon Sep 17 00:00:00 2001
From: "REDMOND\\chiechan" <chiechan@microsoft.com>
Date: Mon, 7 May 2018 19:44:03 -0700
Subject: [PATCH 3/4] added default behavior

---
 .../office-ui-fabric-react/src/components/Button/BaseButton.tsx  | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
index 46eeb333f4182c..a35b30e3b6d9c8 100644
--- a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
+++ b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
@@ -685,6 +685,7 @@ export class BaseButton extends BaseComponent<IBaseButtonProps, IBaseButtonState
     } else if (this.props.menuProps) {
       return ev.which === KeyCodes.down && (ev.altKey || ev.metaKey);
     }
+    return false;
   }
 
   private _onMenuClick = (ev: React.MouseEvent<HTMLDivElement | HTMLAnchorElement>) => {

From 084ec0ea80fd46e32e89791276059b71da4c9957 Mon Sep 17 00:00:00 2001
From: "REDMOND\\chiechan" <chiechan@microsoft.com>
Date: Tue, 8 May 2018 09:29:56 -0700
Subject: [PATCH 4/4] moved comment about keyboard to onClick event

---
 .../src/components/Button/BaseButton.tsx                    | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
index a35b30e3b6d9c8..895d5194fa414c 100644
--- a/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
+++ b/packages/office-ui-fabric-react/src/components/Button/BaseButton.tsx
@@ -639,9 +639,6 @@ export class BaseButton extends BaseComponent<IBaseButtonProps, IBaseButtonState
       ev.preventDefault();
       ev.stopPropagation();
     }
-
-    // Note: When enter is pressed, we will let the event continue to propagate
-    // to trigger the onClick event on the button
   }
 
   private _onTouchStart: () => void = () => {
@@ -685,6 +682,9 @@ export class BaseButton extends BaseComponent<IBaseButtonProps, IBaseButtonState
     } else if (this.props.menuProps) {
       return ev.which === KeyCodes.down && (ev.altKey || ev.metaKey);
     }
+
+    // Note: When enter is pressed, we will let the event continue to propagate
+    // to trigger the onClick event on the button
     return false;
   }