Patchfile for https://openradar.appspot.com/radar?id=4992856901025792 (NSPopover bug)

repro.patch

diff --git a/Base.lproj/Main.storyboard b/Base.lproj/Main.storyboard
index 5344907..1f78691 100644
--- a/Base.lproj/Main.storyboard
+++ b/Base.lproj/Main.storyboard
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.Storyboard.XIB" version="3.0" toolsVersion="9060" systemVersion="14F1021" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" initialViewController="B8D-0N-5wS">
+<document type="com.apple.InterfaceBuilder3.Cocoa.Storyboard.XIB" version="3.0" toolsVersion="9532" systemVersion="15C50" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" initialViewController="B8D-0N-5wS">
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="9060"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="9532"/>
     </dependencies>
     <scenes>
         <!--Application-->
@@ -499,10 +499,22 @@
                                     <action selector="showPopoverAction:" target="XfG-lQ-9wD" id="go1-9h-icb"/>
                                 </connections>
                             </button>
+                            <button verticalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="GFn-3O-osL">
+                                <rect key="frame" x="17" y="40" width="73" height="32"/>
+                                <buttonCell key="cell" type="push" title="Move" bezelStyle="rounded" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="Fhz-p6-2wA">
+                                    <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
+                                    <font key="font" metaFont="system"/>
+                                </buttonCell>
+                                <connections>
+                                    <action selector="movePopoverAction:" target="XfG-lQ-9wD" id="E8k-yG-MUj"/>
+                                </connections>
+                            </button>
                         </subviews>
                     </view>
                     <connections>
                         <outlet property="animatesCheckbox" destination="jgE-QY-9B8" id="c69-wd-OLL"/>
+                        <outlet property="moveButton" destination="GFn-3O-osL" id="aMp-Hj-m1l"/>
+                        <outlet property="popoverButton" destination="268-ex-7BC" id="PM7-Ve-J88"/>
                         <outlet property="popoverPosition" destination="0T0-o6-xmB" id="r3n-7G-hnD"/>
                         <outlet property="popoverType" destination="xL6-IW-ef1" id="5vt-46-FQ9"/>
                         <outlet property="useCustomDetachedWindow" destination="lnL-Xb-cfI" id="d1Z-j6-Kqe"/>
diff --git a/MyViewController.m b/MyViewController.m
index 19c1842..6b456ed 100644
--- a/MyViewController.m
+++ b/MyViewController.m
@@ -16,6 +16,9 @@
 @property (weak) IBOutlet NSButton *animatesCheckbox;
 @property (weak) IBOutlet NSButton *useCustomDetachedWindow;
 
+@property (weak) IBOutlet NSButton *popoverButton;
+@property (weak) IBOutlet NSButton *moveButton;
+
 @property (strong) NSPopover *myPopover;
 @property (strong) MyViewController *popoverViewController;
 
@@ -70,6 +73,9 @@
     _detachedHUDWindow = [[NSPanel alloc] initWithContentRect:rect styleMask:styleMask backing:NSBackingStoreBuffered defer:YES];
     self.detachedHUDWindow.contentViewController = self.popoverViewController;
     self.detachedHUDWindow.releasedWhenClosed = NO;
+    
+    // Trigger this action on mousedown, not mouseup (necessary for repro)
+    [self.moveButton sendActionOn:NSLeftMouseDownMask];
 }
 
 // -------------------------------------------------------------------------------
@@ -101,7 +107,8 @@
         
         // AppKit will close the popover when the user interacts with a user interface element outside the popover.
         // note that interacting with menus or panels that become key only when needed will not cause a transient popover to close.
-        self.myPopover.behavior = NSPopoverBehaviorTransient;
+        self.myPopover.behavior = NSPopoverBehaviorSemitransient; // BUG
+//        self.myPopover.behavior = NSPopoverBehaviorTransient;     // no bug
         
         // so we can be notified when the popover appears or closes
         self.myPopover.delegate = self;
@@ -111,6 +118,14 @@
 // -------------------------------------------------------------------------------
 //  showPopoverAction:sender
 // -------------------------------------------------------------------------------
+- (IBAction)movePopoverAction:(id)sender
+{
+    // Move popoverButton (which the NSPopover is anchored to) to a different location in window
+    NSRect frame = self.popoverButton.frame;
+    frame.origin.x -= 20;
+    self.popoverButton.frame = frame;
+}
+
 - (IBAction)showPopoverAction:(id)sender
 {
     switch (self.popoverType.selectedRow)