Merge branch 'master' into f27

1 files changed, 400 insertions, 31 deletions

diff --git a/complete-csd-window-offset-mozilla-1457691.patch b/complete-csd-window-offset-mozilla-1457691.patch
index e37d02d..a43a518 100644
--- a/complete-csd-window-offset-mozilla-1457691.patch
+++ b/complete-csd-window-offset-mozilla-1457691.patch
@@ -1,5 +1,6 @@
 This is a composition of these patches for Firefox 60:
 
+https://bugzilla.mozilla.org/show_bug.cgi?id=1441873
 https://bugzilla.mozilla.org/show_bug.cgi?id=1441665
 https://bugzilla.mozilla.org/show_bug.cgi?id=1456898
 https://bugzilla.mozilla.org/show_bug.cgi?id=1457309
@@ -7,9 +8,377 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1457691
 
 which fix popup window placement at CSD window mode.
 
-diff -up firefox-60.0/widget/gtk/gtk3drawing.cpp.old firefox-60.0/widget/gtk/gtk3drawing.cpp
---- firefox-60.0/widget/gtk/gtk3drawing.cpp.old	2018-04-26 22:07:36.000000000 +0200
-+++ firefox-60.0/widget/gtk/gtk3drawing.cpp	2018-04-30 11:59:06.750866104 +0200
+
+diff --git a/widget/gtk/nsLookAndFeel.cpp b/widget/gtk/nsLookAndFeel.cpp
+--- a/widget/gtk/nsLookAndFeel.cpp
++++ b/widget/gtk/nsLookAndFeel.cpp
+@@ -1076,19 +1076,18 @@ nsLookAndFeel::EnsureInit()
+                          nullptr);
+ 
+     GetSystemFontInfo(gtk_widget_get_style_context(entry),
+                       &mFieldFontName, &mFieldFontStyle);
+ 
+     gtk_widget_destroy(window);
+     g_object_unref(labelWidget);
+ 
+-    // Require GTK 3.10 for GtkHeaderBar support and compatible window manager.
+-    mCSDAvailable = (gtk_check_version(3, 10, 0) == nullptr &&
+-        nsWindow::GetCSDSupportLevel() != nsWindow::CSD_SUPPORT_NONE);
++    mCSDAvailable =
++        nsWindow::GetSystemCSDSupportLevel() != nsWindow::CSD_SUPPORT_NONE;
+ 
+     mCSDCloseButton = false;
+     mCSDMinimizeButton = false;
+     mCSDMaximizeButton = false;
+ 
+     // We need to initialize whole CSD config explicitly because it's queried
+     // as -moz-gtk* media features.
+     WidgetNodeType buttonLayout[TOOLBAR_BUTTONS];
+diff --git a/widget/gtk/nsWindow.h b/widget/gtk/nsWindow.h
+--- a/widget/gtk/nsWindow.h
++++ b/widget/gtk/nsWindow.h
+@@ -395,28 +395,26 @@ public:
+     // From GDK
+     int GdkCoordToDevicePixels(gint coord);
+     LayoutDeviceIntPoint GdkPointToDevicePixels(GdkPoint point);
+     LayoutDeviceIntPoint GdkEventCoordsToDevicePixels(gdouble x, gdouble y);
+     LayoutDeviceIntRect GdkRectToDevicePixels(GdkRectangle rect);
+ 
+     virtual bool WidgetTypeSupportsAcceleration() override;
+ 
+-    bool DoDrawTitlebar() const;
+-
+     typedef enum { CSD_SUPPORT_SYSTEM,    // CSD including shadows
+                    CSD_SUPPORT_CLIENT,    // CSD without shadows
+                    CSD_SUPPORT_NONE,      // WM does not support CSD at all
+                    CSD_SUPPORT_UNKNOWN
+     } CSDSupportLevel;
+     /**
+      * Get the support of Client Side Decoration by checking
+      * the XDG_CURRENT_DESKTOP environment variable.
+      */
+-    static CSDSupportLevel GetCSDSupportLevel();
++    static CSDSupportLevel GetSystemCSDSupportLevel();
+ 
+ protected:
+     virtual ~nsWindow();
+ 
+     // event handling code
+     void DispatchActivateEvent(void);
+     void DispatchDeactivateEvent(void);
+     void DispatchResized();
+@@ -512,19 +510,21 @@ private:
+     int                 mXDepth;
+     mozilla::widget::WindowSurfaceProvider mSurfaceProvider;
+ #endif
+ 
+     // Upper bound on pending ConfigureNotify events to be dispatched to the
+     // window. See bug 1225044.
+     unsigned int mPendingConfigures;
+ 
+-    bool               mIsCSDAvailable;
++    // Window titlebar rendering mode, CSD_SUPPORT_NONE if it's disabled
++    // for this window.
++    CSDSupportLevel    mCSDSupportLevel;
+     // If true, draw our own window titlebar.
+-    bool               mIsCSDEnabled;
++    bool               mDrawInTitlebar;
+     // Draggable titlebar region maintained by UpdateWindowDraggingRegion
+     LayoutDeviceIntRegion mDraggableRegion;
+ 
+ #ifdef ACCESSIBILITY
+     RefPtr<mozilla::a11y::Accessible> mRootAccessible;
+ 
+     /**
+      * Request to create the accessible for this window if it is top level.
+
+diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
+--- a/widget/gtk/nsWindow.cpp
++++ b/widget/gtk/nsWindow.cpp
+@@ -474,18 +474,18 @@ nsWindow::nsWindow()
+ 
+     mTransparencyBitmapWidth  = 0;
+     mTransparencyBitmapHeight = 0;
+ 
+ #if GTK_CHECK_VERSION(3,4,0)
+     mLastScrollEventTime = GDK_CURRENT_TIME;
+ #endif
+     mPendingConfigures = 0;
+-    mIsCSDAvailable = false;
+-    mIsCSDEnabled = false;
++    mCSDSupportLevel = CSD_SUPPORT_NONE;
++    mDrawInTitlebar = false;
+ }
+ 
+ nsWindow::~nsWindow()
+ {
+     LOG(("nsWindow::~nsWindow() [%p]\n", (void *)this));
+ 
+     delete[] mTransparencyBitmap;
+     mTransparencyBitmap = nullptr;
+@@ -2814,17 +2814,17 @@ nsWindow::OnButtonReleaseEvent(GdkEventB
+     LayoutDeviceIntPoint pos = event.mRefPoint;
+ 
+     nsEventStatus eventStatus = DispatchInputEvent(&event);
+ 
+     bool defaultPrevented = (eventStatus == nsEventStatus_eConsumeNoDefault);
+     // Check if mouse position in titlebar and doubleclick happened to
+     // trigger restore/maximize.
+     if (!defaultPrevented
+-             && mIsCSDEnabled
++             && mDrawInTitlebar
+              && event.button == WidgetMouseEvent::eLeftButton
+              && event.mClickCount == 2
+              && mDraggableRegion.Contains(pos.x, pos.y)) {
+ 
+         if (mSizeState == nsSizeMode_Maximized) {
+             SetSizeMode(nsSizeMode_Normal);
+         } else {
+             SetSizeMode(nsSizeMode_Maximized);
+@@ -3758,22 +3758,18 @@ nsWindow::Create(nsIWidget* aParent,
+             gtk_window_set_wmclass(GTK_WINDOW(mShell), "Toplevel",
+                                    gdk_get_program_class());
+ 
+             // each toplevel window gets its own window group
+             GtkWindowGroup *group = gtk_window_group_new();
+             gtk_window_group_add_window(group, GTK_WINDOW(mShell));
+             g_object_unref(group);
+ 
+-            int32_t isCSDAvailable = false;
+-            nsresult rv = LookAndFeel::GetInt(LookAndFeel::eIntID_GTKCSDAvailable,
+-                                              &isCSDAvailable);
+-            if (NS_SUCCEEDED(rv)) {
+-               mIsCSDAvailable = isCSDAvailable;
+-            }
++            // We enable titlebar rendering for toplevel windows only.
++            mCSDSupportLevel = GetSystemCSDSupportLevel();
+         }
+ 
+         // Create a container to hold child windows and child GtkWidgets.
+         GtkWidget *container = moz_container_new();
+         mContainer = MOZ_CONTAINER(container);
+ 
+         // "csd" style is set when widget is realized so we need to call
+         // it explicitly now.
+@@ -3788,17 +3784,17 @@ nsWindow::Create(nsIWidget* aParent,
+          *    are drawn by Gtk+ to mShell. Content is rendered to mContainer
+          *    and we listen to the Gtk+ events on mContainer.
+          * 3) We're running on Wayland. All gecko content is rendered
+          *    to mContainer and we listen to the Gtk+ events on mContainer.
+          */
+         GtkStyleContext* style = gtk_widget_get_style_context(mShell);
+         drawToContainer =
+             !mIsX11Display ||
+-            (mIsCSDAvailable && GetCSDSupportLevel() == CSD_SUPPORT_CLIENT) ||
++            (mCSDSupportLevel == CSD_SUPPORT_CLIENT) ||
+             gtk_style_context_has_class(style, "csd");
+         eventWidget = (drawToContainer) ? container : mShell;
+ 
+         gtk_widget_add_events(eventWidget, kEvents);
+         if (drawToContainer)
+             gtk_widget_add_events(mShell, GDK_PROPERTY_CHANGE_MASK);
+ 
+         // Prevent GtkWindow from painting a background to avoid flickering.
+@@ -6581,90 +6577,91 @@ nsWindow::ClearCachedResources()
+             window->ClearCachedResources();
+         }
+     }
+ }
+ 
+ nsresult
+ nsWindow::SetNonClientMargins(LayoutDeviceIntMargin &aMargins)
+ {
+-  SetDrawsInTitlebar(aMargins.top == 0);
+-  return NS_OK;
++    SetDrawsInTitlebar(aMargins.top == 0);
++    return NS_OK;
+ }
+ 
+ void
+ nsWindow::SetDrawsInTitlebar(bool aState)
+ {
+-  if (!mIsCSDAvailable || aState == mIsCSDEnabled)
+-      return;
+-
+-  if (mShell) {
+-      if (GetCSDSupportLevel() == CSD_SUPPORT_SYSTEM) {
+-          SetWindowDecoration(aState ? eBorderStyle_border : mBorderStyle);
+-      }
+-      else {
+-          /* Window manager does not support GDK_DECOR_BORDER,
+-           * emulate it by CSD.
+-           *
+-           * gtk_window_set_titlebar() works on unrealized widgets only,
+-           * we need to handle mShell carefully here.
+-           * When CSD is enabled mGdkWindow is owned by mContainer which is good
+-           * as we can't delete our mGdkWindow. To make mShell unrealized while
+-           * mContainer is preserved we temporary reparent mContainer to an
+-           * invisible GtkWindow.
+-           */
+-          NativeShow(false);
+-
+-          // Using GTK_WINDOW_POPUP rather than
+-          // GTK_WINDOW_TOPLEVEL in the hope that POPUP results in less
+-          // initialization and window manager interaction.
+-          GtkWidget* tmpWindow = gtk_window_new(GTK_WINDOW_POPUP);
+-          gtk_widget_realize(tmpWindow);
+-
+-          gtk_widget_reparent(GTK_WIDGET(mContainer), tmpWindow);
+-          gtk_widget_unrealize(GTK_WIDGET(mShell));
+-
+-          // Available as of GTK 3.10+
+-          static auto sGtkWindowSetTitlebar = (void (*)(GtkWindow*, GtkWidget*))
+-              dlsym(RTLD_DEFAULT, "gtk_window_set_titlebar");
+-          MOZ_ASSERT(sGtkWindowSetTitlebar,
+-              "Missing gtk_window_set_titlebar(), old Gtk+ library?");
+-
+-          if (aState) {
+-              // Add a hidden titlebar widget to trigger CSD, but disable the default
+-              // titlebar.  GtkFixed is a somewhat random choice for a simple unused
+-              // widget. gtk_window_set_titlebar() takes ownership of the titlebar
+-              // widget.
+-              sGtkWindowSetTitlebar(GTK_WINDOW(mShell), gtk_fixed_new());
+-          } else {
+-              sGtkWindowSetTitlebar(GTK_WINDOW(mShell), nullptr);
+-          }
+-
+-          /* A workaround for https://bugzilla.gnome.org/show_bug.cgi?id=791081
+-           * gtk_widget_realize() throws:
+-           * "In pixman_region32_init_rect: Invalid rectangle passed"
+-           * when mShell has default 1x1 size.
+-           */
+-          GtkAllocation allocation = {0, 0, 0, 0};
+-          gtk_widget_get_preferred_width(GTK_WIDGET(mShell), nullptr,
+-                                         &allocation.width);
+-          gtk_widget_get_preferred_height(GTK_WIDGET(mShell), nullptr,
+-                                          &allocation.height);
+-          gtk_widget_size_allocate(GTK_WIDGET(mShell), &allocation);
+-
+-          gtk_widget_realize(GTK_WIDGET(mShell));
+-          gtk_widget_reparent(GTK_WIDGET(mContainer), GTK_WIDGET(mShell));
+-          mNeedsShow = true;
+-          NativeResize();
+-
+-          gtk_widget_destroy(tmpWindow);
+-      }
+-  }
+-
+-  mIsCSDEnabled = aState;
++    if (!mShell ||
++        mCSDSupportLevel == CSD_SUPPORT_NONE ||
++        aState == mDrawInTitlebar) {
++        return;
++    }
++
++    if (mCSDSupportLevel == CSD_SUPPORT_SYSTEM) {
++        SetWindowDecoration(aState ? eBorderStyle_border : mBorderStyle);
++    }
++    else if (mCSDSupportLevel == CSD_SUPPORT_CLIENT) {
++        /* Window manager does not support GDK_DECOR_BORDER,
++         * emulate it by CSD.
++         *
++         * gtk_window_set_titlebar() works on unrealized widgets only,
++         * we need to handle mShell carefully here.
++         * When CSD is enabled mGdkWindow is owned by mContainer which is good
++         * as we can't delete our mGdkWindow. To make mShell unrealized while
++         * mContainer is preserved we temporary reparent mContainer to an
++         * invisible GtkWindow.
++         */
++        NativeShow(false);
++
++        // Using GTK_WINDOW_POPUP rather than
++        // GTK_WINDOW_TOPLEVEL in the hope that POPUP results in less
++        // initialization and window manager interaction.
++        GtkWidget* tmpWindow = gtk_window_new(GTK_WINDOW_POPUP);
++        gtk_widget_realize(tmpWindow);
++
++        gtk_widget_reparent(GTK_WIDGET(mContainer), tmpWindow);
++        gtk_widget_unrealize(GTK_WIDGET(mShell));
++
++        // Available as of GTK 3.10+
++        static auto sGtkWindowSetTitlebar = (void (*)(GtkWindow*, GtkWidget*))
++            dlsym(RTLD_DEFAULT, "gtk_window_set_titlebar");
++        MOZ_ASSERT(sGtkWindowSetTitlebar,
++            "Missing gtk_window_set_titlebar(), old Gtk+ library?");
++
++        if (aState) {
++            // Add a hidden titlebar widget to trigger CSD, but disable the default
++            // titlebar.  GtkFixed is a somewhat random choice for a simple unused
++            // widget. gtk_window_set_titlebar() takes ownership of the titlebar
++            // widget.
++            sGtkWindowSetTitlebar(GTK_WINDOW(mShell), gtk_fixed_new());
++        } else {
++            sGtkWindowSetTitlebar(GTK_WINDOW(mShell), nullptr);
++        }
++
++        /* A workaround for https://bugzilla.gnome.org/show_bug.cgi?id=791081
++         * gtk_widget_realize() throws:
++         * "In pixman_region32_init_rect: Invalid rectangle passed"
++         * when mShell has default 1x1 size.
++         */
++        GtkAllocation allocation = {0, 0, 0, 0};
++        gtk_widget_get_preferred_width(GTK_WIDGET(mShell), nullptr,
++                                       &allocation.width);
++        gtk_widget_get_preferred_height(GTK_WIDGET(mShell), nullptr,
++                                        &allocation.height);
++        gtk_widget_size_allocate(GTK_WIDGET(mShell), &allocation);
++
++        gtk_widget_realize(GTK_WIDGET(mShell));
++        gtk_widget_reparent(GTK_WIDGET(mContainer), GTK_WIDGET(mShell));
++        mNeedsShow = true;
++        NativeResize();
++
++        gtk_widget_destroy(tmpWindow);
++    }
++
++    mDrawInTitlebar = aState;
+ }
+ 
+ gint
+ nsWindow::GdkScaleFactor()
+ {
+ #if (MOZ_WIDGET_GTK >= 3)
+     // Available as of GTK 3.10+
+     static auto sGdkWindowGetScaleFactorPtr = (gint (*)(GdkWindow*))
+@@ -6923,28 +6920,28 @@ nsWindow::SynthesizeNativeTouchPoint(uin
+   event.touch.y = DevicePixelsToGdkCoordRoundDown(pointInWindow.y);
+ 
+   gdk_event_put(&event);
+ 
+   return NS_OK;
+ }
+ #endif
+ 
+-bool
+-nsWindow::DoDrawTitlebar() const
+-{
+-    return mIsCSDEnabled && mSizeState == nsSizeMode_Normal;
+-}
+-
+ nsWindow::CSDSupportLevel
+-nsWindow::GetCSDSupportLevel() {
++nsWindow::GetSystemCSDSupportLevel() {
+     if (sCSDSupportLevel != CSD_SUPPORT_UNKNOWN) {
+         return sCSDSupportLevel;
+     }
+ 
++    // Require GTK 3.10 for GtkHeaderBar support and compatible window manager.
++    if (gtk_check_version(3, 10, 0) != nullptr) {
++        sCSDSupportLevel = CSD_SUPPORT_NONE;
++        return sCSDSupportLevel;
++    }
++
+     const char* currentDesktop = getenv("XDG_CURRENT_DESKTOP");
+     if (currentDesktop) {
+         // GNOME Flashback (fallback)
+         if (strstr(currentDesktop, "GNOME-Flashback:GNOME") != nullptr) {
+             sCSDSupportLevel = CSD_SUPPORT_CLIENT;
+         // gnome-shell
+         } else if (strstr(currentDesktop, "GNOME") != nullptr) {
+             sCSDSupportLevel = CSD_SUPPORT_SYSTEM;
+diff -up firefox-60.0/widget/gtk/gtk3drawing.cpp.orig firefox-60.0/widget/gtk/gtk3drawing.cpp
+--- firefox-60.0/widget/gtk/gtk3drawing.cpp.orig	2018-04-26 22:07:36.000000000 +0200
++++ firefox-60.0/widget/gtk/gtk3drawing.cpp	2018-04-30 13:38:19.083949868 +0200
 @@ -38,6 +38,16 @@ static ToolbarGTKMetrics sToolbarMetrics
  #define GTK_STATE_FLAG_CHECKED (1 << 11)
  #endif
@@ -104,9 +473,9 @@ diff -up firefox-60.0/widget/gtk/gtk3drawing.cpp.old firefox-60.0/widget/gtk/gtk
  /* cairo_t *cr argument has to be a system-cairo. */
  gint
  moz_gtk_widget_paint(WidgetNodeType widget, cairo_t *cr,
-diff -up firefox-60.0/widget/gtk/gtkdrawing.h.old firefox-60.0/widget/gtk/gtkdrawing.h
---- firefox-60.0/widget/gtk/gtkdrawing.h.old	2018-04-26 22:07:35.000000000 +0200
-+++ firefox-60.0/widget/gtk/gtkdrawing.h	2018-04-30 11:59:06.750866104 +0200
+diff -up firefox-60.0/widget/gtk/gtkdrawing.h.orig firefox-60.0/widget/gtk/gtkdrawing.h
+--- firefox-60.0/widget/gtk/gtkdrawing.h.orig	2018-04-26 22:07:35.000000000 +0200
++++ firefox-60.0/widget/gtk/gtkdrawing.h	2018-04-30 13:38:19.083949868 +0200
 @@ -334,6 +334,10 @@ typedef enum {
     */
    MOZ_GTK_HEADER_BAR_BUTTON_MAXIMIZE_RESTORE,
@@ -136,9 +505,9 @@ diff -up firefox-60.0/widget/gtk/gtkdrawing.h.old firefox-60.0/widget/gtk/gtkdra
 +GetCSDDecorationSize(GtkWindow *aGtkWindow, GtkBorder* aDecorationSize);
 +
  #endif
-diff -up firefox-60.0/widget/gtk/nsWindow.cpp.old firefox-60.0/widget/gtk/nsWindow.cpp
---- firefox-60.0/widget/gtk/nsWindow.cpp.old	2018-04-30 12:01:38.788343254 +0200
-+++ firefox-60.0/widget/gtk/nsWindow.cpp	2018-04-30 12:00:01.012679502 +0200
+diff -up firefox-60.0/widget/gtk/nsWindow.cpp.orig firefox-60.0/widget/gtk/nsWindow.cpp
+--- firefox-60.0/widget/gtk/nsWindow.cpp.orig	2018-04-30 13:37:32.145122854 +0200
++++ firefox-60.0/widget/gtk/nsWindow.cpp	2018-04-30 13:39:12.593752681 +0200
 @@ -127,6 +127,7 @@ using namespace mozilla::widget;
  #endif
  
@@ -158,7 +527,7 @@ diff -up firefox-60.0/widget/gtk/nsWindow.cpp.old firefox-60.0/widget/gtk/nsWind
  }
  
  void
-@@ -6556,6 +6561,32 @@ nsWindow::ClearCachedResources()
+@@ -6552,6 +6557,32 @@ nsWindow::ClearCachedResources()
      }
  }
  
@@ -191,24 +560,24 @@ diff -up firefox-60.0/widget/gtk/nsWindow.cpp.old firefox-60.0/widget/gtk/nsWind
  nsresult
  nsWindow::SetNonClientMargins(LayoutDeviceIntMargin &aMargins)
  {
-@@ -6628,6 +6659,13 @@ nsWindow::SetDrawsInTitlebar(bool aState
-           mNeedsShow = true;
-           NativeResize();
- 
-+          // When we use system titlebar setup managed by Gtk+ we also get
-+          // _NET_FRAME_EXTENTS property for our toplevel window so we can't
-+          // update the client offset it here.
-+          if (aState) {
-+              UpdateClientOffsetForCSDWindow();
-+          }
-+
-           gtk_widget_destroy(tmpWindow);
-       }
-   }
-diff -up firefox-60.0/widget/gtk/nsWindow.h.old firefox-60.0/widget/gtk/nsWindow.h
---- firefox-60.0/widget/gtk/nsWindow.h.old	2018-04-26 22:07:35.000000000 +0200
-+++ firefox-60.0/widget/gtk/nsWindow.h	2018-04-30 11:57:33.656146337 +0200
-@@ -456,6 +456,8 @@ private:
+@@ -6626,6 +6657,13 @@ nsWindow::SetDrawsInTitlebar(bool aState
+         mNeedsShow = true;
+         NativeResize();
+ 
++        // When we use system titlebar setup managed by Gtk+ we also get
++        // _NET_FRAME_EXTENTS property for our toplevel window so we can't
++        // update the client offset it here.
++        if (aState) {
++            UpdateClientOffsetForCSDWindow();
++        }
++
+         gtk_widget_destroy(tmpWindow);
+     }
+ 
+diff -up firefox-60.0/widget/gtk/nsWindow.h.orig firefox-60.0/widget/gtk/nsWindow.h
+--- firefox-60.0/widget/gtk/nsWindow.h.orig	2018-04-30 13:37:32.143122861 +0200
++++ firefox-60.0/widget/gtk/nsWindow.h	2018-04-30 13:38:19.085949861 +0200
+@@ -454,6 +454,8 @@ private:
      nsIWidgetListener* GetListener();
      bool               IsComposited() const;
  
@@ -217,9 +586,9 @@ diff -up firefox-60.0/widget/gtk/nsWindow.h.old firefox-60.0/widget/gtk/nsWindow
      GtkWidget          *mShell;
      MozContainer       *mContainer;
      GdkWindow          *mGdkWindow;
-diff -up firefox-60.0/widget/gtk/WidgetStyleCache.cpp.old firefox-60.0/widget/gtk/WidgetStyleCache.cpp
---- firefox-60.0/widget/gtk/WidgetStyleCache.cpp.old	2018-04-26 22:07:35.000000000 +0200
-+++ firefox-60.0/widget/gtk/WidgetStyleCache.cpp	2018-04-30 13:07:04.170056312 +0200
+diff -up firefox-60.0/widget/gtk/WidgetStyleCache.cpp.orig firefox-60.0/widget/gtk/WidgetStyleCache.cpp
+--- firefox-60.0/widget/gtk/WidgetStyleCache.cpp.orig	2018-04-26 22:07:35.000000000 +0200
++++ firefox-60.0/widget/gtk/WidgetStyleCache.cpp	2018-04-30 13:38:19.085949861 +0200
 @@ -1285,6 +1285,22 @@ GetCssNodeStyleInternal(WidgetNodeType a
            "MOZ_GTK_HEADER_BAR_BUTTON_RESTORE is used as an icon only!");
        return nullptr;