Bug 1768360 [Wayland] Don't use move-to-rect with invalid/missing anchor r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D146782

widget/gtk/nsWindow.cpp

@@ -2108,7 +2108,7 @@ void nsWindow::NativeMoveResizeWaylandPopup(bool aMove, bool aResize) {
 
   bool trackedInHierarchy = WaylandPopupConfigure();
 
-  // Read popup position from layout if it was moved.
+  // Read popup position from layout if it was moved or newly created.
   // This position is used by move-to-rect method as we need anchor and other
   // info to place popup correctly.
   // We need WaylandPopupConfigure() to be called before to have all needed
@@ -2356,10 +2356,14 @@ nsWindow::WaylandPopupGetPositionFromLayout() {
   }
 
   return {
-      anchorRect, rectAnchor, menuAnchor, hints,
+      anchorRect,
+      rectAnchor,
+      menuAnchor,
+      hints,
       DevicePixelsToGdkPointRoundDown(LayoutDevicePoint::FromAppUnitsToNearest(
           popupMargin.mPopupOffset,
-          popupFrame->PresContext()->AppUnitsPerDevPixel()))};
+          popupFrame->PresContext()->AppUnitsPerDevPixel())),
+      true};
 }
 
 void nsWindow::WaylandPopupMove() {
@@ -2370,19 +2374,28 @@ void nsWindow::WaylandPopupMove() {
       GdkWindow*, const GdkRectangle*, GdkGravity, GdkGravity, GdkAnchorHints,
       gint, gint))dlsym(RTLD_DEFAULT, "gdk_window_move_to_rect");
 
-  GdkWindow* gdkWindow = gtk_widget_get_window(GTK_WIDGET(mShell));
-  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
-
   LOG("  original widget popup position [%d, %d]\n", mPopupPosition.x,
       mPopupPosition.y);
   LOG("  relative widget popup position [%d, %d]\n", mRelativePopupPosition.x,
       mRelativePopupPosition.y);
 
-  if (mPopupUseMoveToRect) {
-    mPopupUseMoveToRect = sGdkWindowMoveToRect && gdkWindow && popupFrame;
+  if (mPopupUseMoveToRect && !sGdkWindowMoveToRect) {
+    LOG("  can't use move-to-rect due missing gdk_window_move_to_rect()");
+    mPopupUseMoveToRect = false;
   }
 
-  LOG(" popup use move to rect %d\n", mPopupUseMoveToRect);
+  GdkWindow* gdkWindow = gtk_widget_get_window(GTK_WIDGET(mShell));
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  if (mPopupUseMoveToRect && !gdkWindow || !popupFrame) {
+    LOG("  can't use move-to-rect due missing gdkWindow or popupFrame");
+    mPopupUseMoveToRect = false;
+  }
+  if (mPopupUseMoveToRect && !mPopupMoveToRectParams.mAnchorSet) {
+    LOG("  can't use move-to-rect due missing anchor");
+    mPopupUseMoveToRect = false;
+  }
+
+  LOG("  popup use move to rect %d\n", mPopupUseMoveToRect);
 
   if (!mPopupUseMoveToRect) {
     if (mNeedsShow && mPopupType != ePopupTypeTooltip) {

widget/gtk/nsWindow.h

@@ -705,11 +705,12 @@ class nsWindow final : public nsBaseWidget {
   // we need to reuse last GdkWindowMoveToRect params to avoid
   // popup movement.
   struct WaylandPopupMoveToRectParams {
-    LayoutDeviceIntRect mAnchorRect;
-    GdkGravity mAnchorRectType;
-    GdkGravity mPopupAnchorType;
-    GdkAnchorHints mHints;
-    GdkPoint mOffset;
+    LayoutDeviceIntRect mAnchorRect = {0, 0, 0, 0};
+    GdkGravity mAnchorRectType = GDK_GRAVITY_NORTH_WEST;
+    GdkGravity mPopupAnchorType = GDK_GRAVITY_NORTH_WEST;
+    GdkAnchorHints mHints = GDK_ANCHOR_SLIDE;
+    GdkPoint mOffset = {0, 0};
+    bool mAnchorSet = false;
   };
 
   WaylandPopupMoveToRectParams mPopupMoveToRectParams;