1 files changed, 122 insertions, 0 deletions
diff --git a/mozilla-1493081.patch b/mozilla-1493081.patch
new file mode 100644
index 0000000..a3ab9ef
--- /dev/null
+++ b/mozilla-1493081.patch
@@ -0,0 +1,122 @@
+diff --git a/view/nsView.cpp b/view/nsView.cpp
+--- a/view/nsView.cpp
++++ b/view/nsView.cpp
+@@ -320,7 +320,6 @@
+   // Stash a copy of these and use them so we can handle this being deleted (say
+   // from sync painting/flushing from Show/Move/Resize on the widget).
+   LayoutDeviceIntRect newBounds;
+-  RefPtr<nsDeviceContext> dx = mViewManager->GetDeviceContext();
+ 
+   nsWindowType type = widget->WindowType();
+ 
+@@ -360,7 +359,8 @@
+   // because of the potential for device-pixel coordinate spaces for mixed
+   // hidpi/lodpi screens to overlap each other and result in bad placement
+   // (bug 814434).
+-  DesktopToLayoutDeviceScale scale = dx->GetDesktopToDeviceScale();
++
++  DesktopToLayoutDeviceScale scale = widget->GetDesktopToDeviceScaleByScreen();
+ 
+   DesktopRect deskRect = newBounds / scale;
+   if (changedPos) {
+diff --git a/widget/gtk/nsWindow.h b/widget/gtk/nsWindow.h
+--- a/widget/gtk/nsWindow.h
++++ b/widget/gtk/nsWindow.h
+@@ -125,6 +125,7 @@
+     virtual float      GetDPI() override;
+     virtual double     GetDefaultScaleInternal() override;
+     mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScale() override;
++    mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScaleByScreen() override;
+     virtual void       SetParent(nsIWidget* aNewParent) override;
+     virtual void       SetModal(bool aModal) override;
+     virtual bool       IsVisible() const override;
+diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
+--- a/widget/gtk/nsWindow.cpp
++++ b/widget/gtk/nsWindow.cpp
+@@ -57,6 +57,7 @@
+ 
+ #if defined(MOZ_WAYLAND)
+ #include <gdk/gdkwayland.h>
++#include "nsView.h"
+ #endif
+ 
+ #include "nsGkAtoms.h"
+@@ -841,6 +842,37 @@
+     return DesktopToLayoutDeviceScale(1.0);
+ }
+ 
++DesktopToLayoutDeviceScale
++nsWindow::GetDesktopToDeviceScaleByScreen()
++{
++#ifdef MOZ_WAYLAND
++    GdkDisplay* gdkDisplay = gdk_display_get_default();
++    // In Wayland there's no way to get absolute position of the window and use it to
++    // determine the screen factor of the monitor on which the window is placed.
++    // The window is notified of the current scale factor but not at this point,
++    // so the GdkScaleFactor can return wrong value which can lead to wrong popup
++    // placement.
++    // We need to use parent's window scale factor for the new one.
++    if (GDK_IS_WAYLAND_DISPLAY(gdkDisplay)) {
++        nsView* view = nsView::GetViewFor(this);
++        if (view) {
++            nsView* parentView = view->GetParent();
++            if (parentView) {
++                nsIWidget* parentWidget = parentView->GetNearestWidget(nullptr);
++                if (parentWidget) {
++                    return DesktopToLayoutDeviceScale(parentWidget->RoundsWidgetCoordinatesTo());
++                } else {
++                    NS_WARNING("Widget has no parent");
++                }
++            }
++        } else {
++            NS_WARNING("Cannot find widget view");
++        }
++    }
++#endif
++    return nsBaseWidget::GetDesktopToDeviceScale();
++}
++
+ void
+ nsWindow::SetParent(nsIWidget *aNewParent)
+ {
+diff --git a/widget/nsBaseWidget.h b/widget/nsBaseWidget.h
+--- a/widget/nsBaseWidget.h
++++ b/widget/nsBaseWidget.h
+@@ -24,6 +24,8 @@
+ #include "nsIWidgetListener.h"
+ #include "nsPIDOMWindow.h"
+ #include "nsWeakReference.h"
++#include "nsView.h"
++#include "nsViewManager.h"
+ #include <algorithm>
+ 
+ #if defined(XP_WIN)
+@@ -238,6 +240,10 @@
+   mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScale() override {
+     return mozilla::DesktopToLayoutDeviceScale(1.0);
+   }
++  mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScaleByScreen() override {
++    return (nsView::GetViewFor(this)->GetViewManager()->GetDeviceContext())->GetDesktopToDeviceScale();
++  }
++
+   virtual void            ConstrainPosition(bool aAllowSlop,
+                                             int32_t *aX,
+                                             int32_t *aY) override {}
+diff --git a/widget/nsIWidget.h b/widget/nsIWidget.h
+--- a/widget/nsIWidget.h
++++ b/widget/nsIWidget.h
+@@ -578,6 +578,13 @@
+     virtual mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScale() = 0;
+ 
+     /**
++     * Return the scaling factor between device pixels and the platform-
++     * dependent "desktop pixels" by looking up the screen by the position
++     * of the widget.
++     */
++    virtual mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScaleByScreen() = 0;
++
++    /**
+      * Return the default scale factor for the window. This is the
+      * default number of device pixels per CSS pixel to use. This should
+      * depend on OS/platform settings such as the Mac's "UI scale factor"
+