From 0e3579470d2c38bca4ec88cba4ded35794598f27 Mon Sep 17 00:00:00 2001
From: Phil Tucker <phtucker@microsoft.com>
Date: Mon, 29 Apr 2019 15:35:54 -0400
Subject: [PATCH 1/2] Fix return focus handling in DatePicker and
 FocusTrapZone.

---
 .../src/components/DatePicker/DatePicker.base.tsx          | 7 +------
 .../src/components/FocusTrapZone/FocusTrapZone.tsx         | 7 ++++++-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/packages/office-ui-fabric-react/src/components/DatePicker/DatePicker.base.tsx b/packages/office-ui-fabric-react/src/components/DatePicker/DatePicker.base.tsx
index 5eaea8b756aee..6c869d3062da0 100644
--- a/packages/office-ui-fabric-react/src/components/DatePicker/DatePicker.base.tsx
+++ b/packages/office-ui-fabric-react/src/components/DatePicker/DatePicker.base.tsx
@@ -129,11 +129,6 @@ export class DatePickerBase extends BaseComponent<IDatePickerProps, IDatePickerS
 
   public componentDidUpdate(prevProps: IDatePickerProps, prevState: IDatePickerState) {
     if (prevState.isDatePickerShown && !this.state.isDatePickerShown) {
-      // In browsers like IE, textfield gets unfocused when datepicker is collapsed
-      if (this.props.allowTextInput) {
-        this._async.requestAnimationFrame(() => this.focus());
-      }
-
       // If DatePicker's menu (Calendar) is closed, run onAfterMenuDismiss
       if (this.props.onAfterMenuDismiss) {
         this.props.onAfterMenuDismiss();
@@ -236,7 +231,7 @@ export class DatePickerBase extends BaseComponent<IDatePickerProps, IDatePickerS
             onDismiss={this._calendarDismissed}
             onPositioned={this._onCalloutPositioned}
           >
-            <FocusTrapZone isClickableOutsideFocusTrap={true} disableFirstFocus={this.props.disableAutoFocus}>
+            <FocusTrapZone isClickableOutsideFocusTrap={true} disableFirstFocus={this.props.disableAutoFocus} forceFocusInsideTrap={false}>
               <CalendarType
                 {...calendarProps}
                 onSelectDate={this._onSelectDate}
diff --git a/packages/office-ui-fabric-react/src/components/FocusTrapZone/FocusTrapZone.tsx b/packages/office-ui-fabric-react/src/components/FocusTrapZone/FocusTrapZone.tsx
index 7da1c3a7daba1..5506d7b444ce9 100644
--- a/packages/office-ui-fabric-react/src/components/FocusTrapZone/FocusTrapZone.tsx
+++ b/packages/office-ui-fabric-react/src/components/FocusTrapZone/FocusTrapZone.tsx
@@ -62,7 +62,12 @@ export class FocusTrapZone extends React.Component<IFocusTrapZoneProps, {}> impl
   }
 
   public componentWillUnmount(): void {
-    if (!this.props.disabled) {
+    // don't handle return focus unless forceFocusInsideTrap is true or focus is still within FocusTrapZone
+    if (
+      !this.props.disabled ||
+      this.props.forceFocusInsideTrap ||
+      !elementContains(this._root.current, document.activeElement as HTMLElement)
+    ) {
       this._returnFocusToInitiator();
     }
   }

From ffe0af0d96eabb4f803593688fc43cc6b2903594 Mon Sep 17 00:00:00 2001
From: Phil Tucker <phtucker@microsoft.com>
Date: Mon, 29 Apr 2019 15:42:09 -0400
Subject: [PATCH 2/2] Change request.

---
 .../phtucker-focus_fix_2019-04-29-19-41.json          | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 common/changes/office-ui-fabric-react/phtucker-focus_fix_2019-04-29-19-41.json

diff --git a/common/changes/office-ui-fabric-react/phtucker-focus_fix_2019-04-29-19-41.json b/common/changes/office-ui-fabric-react/phtucker-focus_fix_2019-04-29-19-41.json
new file mode 100644
index 0000000000000..f0d18fb3e65a1
--- /dev/null
+++ b/common/changes/office-ui-fabric-react/phtucker-focus_fix_2019-04-29-19-41.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "Remove out-of-date IE focus handling work-around. Pass forceFocusInsideTrap={false} to DatePicker FocusTrapZone. Adjust FocusTrapZone return focus handling.",
+      "type": "patch"
+    }
+  ],
+  "packageName": "office-ui-fabric-react",
+  "email": "phtucker@microsoft.com"
+}
\ No newline at end of file