From 8233cf36884cf07074f612300c1e014bf9057df2 Mon Sep 17 00:00:00 2001
From: Carlos Garnacho <carlosg@gnome.org>
Date: Sat, 9 Dec 2017 21:13:05 +0100
Subject: [PATCH] gtkwindow: Allow edge resizing from corners if constraints
 forbid either side

The fix is twofold. First, when checking that a corner is resizable, we must
check the constraints on both edges. Second, when checking either edge we
must include both perpendicular sides in order to allow those to be
resizable when the constraint does not allow resizing the edge being
checked.
---
 gtk/gtkwindow.c | 66 ++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 54 insertions(+), 12 deletions(-)

diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 260e61bffb..d7e5613f80 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -1692,6 +1692,33 @@ device_removed_cb (GdkSeat   *seat,
     }
 }
 
+static guint
+constraints_for_edge (GdkWindowEdge edge)
+{
+  switch (edge)
+    {
+    case GDK_WINDOW_EDGE_NORTH_WEST:
+      return GDK_WINDOW_STATE_LEFT_RESIZABLE | GDK_WINDOW_STATE_TOP_RESIZABLE;
+    case GDK_WINDOW_EDGE_NORTH:
+      return GDK_WINDOW_STATE_TOP_RESIZABLE;
+    case GDK_WINDOW_EDGE_NORTH_EAST:
+      return GDK_WINDOW_STATE_RIGHT_RESIZABLE | GDK_WINDOW_STATE_TOP_RESIZABLE;
+    case GDK_WINDOW_EDGE_WEST:
+      return GDK_WINDOW_STATE_LEFT_RESIZABLE;
+    case GDK_WINDOW_EDGE_EAST:
+      return GDK_WINDOW_STATE_RIGHT_RESIZABLE;
+    case GDK_WINDOW_EDGE_SOUTH_WEST:
+      return GDK_WINDOW_STATE_LEFT_RESIZABLE | GDK_WINDOW_STATE_BOTTOM_RESIZABLE;
+    case GDK_WINDOW_EDGE_SOUTH:
+      return GDK_WINDOW_STATE_BOTTOM_RESIZABLE;
+    case GDK_WINDOW_EDGE_SOUTH_EAST:
+      return GDK_WINDOW_STATE_RIGHT_RESIZABLE | GDK_WINDOW_STATE_BOTTOM_RESIZABLE;
+    default:
+      g_warn_if_reached ();
+      return 0;
+    }
+}
+
 static gboolean
 edge_under_coordinates (GtkWindow     *window,
                         gint           x,
@@ -1704,6 +1731,7 @@ edge_under_coordinates (GtkWindow     *window,
   gint handle_v, handle_h;
   GtkBorder border;
   gboolean supports_edge_constraints;
+  guint constraints;
 
   if (priv->type != GTK_WINDOW_TOPLEVEL ||
       !priv->client_decorated ||
@@ -1713,15 +1741,13 @@ edge_under_coordinates (GtkWindow     *window,
     return FALSE;
 
   supports_edge_constraints = gdk_window_supports_edge_constraints (_gtk_widget_get_window (GTK_WIDGET (window)));
+  constraints = constraints_for_edge (edge);
 
   if (!supports_edge_constraints && priv->tiled)
     return FALSE;
 
   if (supports_edge_constraints &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_TOP_RESIZABLE) &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_RIGHT_RESIZABLE) &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_BOTTOM_RESIZABLE) &&
-      !(priv->edge_constraints & GDK_WINDOW_STATE_LEFT_RESIZABLE))
+      (priv->edge_constraints & constraints) != constraints)
     return FALSE;
 
   _gtk_widget_get_allocation (GTK_WIDGET (window), &allocation);
@@ -1755,22 +1781,30 @@ edge_under_coordinates (GtkWindow     *window,
     {
       if (edge != GDK_WINDOW_EDGE_NORTH_WEST &&
           edge != GDK_WINDOW_EDGE_WEST &&
-          edge != GDK_WINDOW_EDGE_SOUTH_WEST)
+          edge != GDK_WINDOW_EDGE_SOUTH_WEST &&
+          edge != GDK_WINDOW_EDGE_NORTH &&
+          edge != GDK_WINDOW_EDGE_SOUTH)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_LEFT_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_NORTH ||
+           edge == GDK_WINDOW_EDGE_SOUTH) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_WEST)))
         return FALSE;
     }
   else if (x >= allocation.x + allocation.width - border.right - handle_h)
     {
       if (edge != GDK_WINDOW_EDGE_NORTH_EAST &&
           edge != GDK_WINDOW_EDGE_EAST &&
-          edge != GDK_WINDOW_EDGE_SOUTH_EAST)
+          edge != GDK_WINDOW_EDGE_SOUTH_EAST &&
+          edge != GDK_WINDOW_EDGE_NORTH &&
+          edge != GDK_WINDOW_EDGE_SOUTH)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_RIGHT_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_NORTH ||
+           edge == GDK_WINDOW_EDGE_SOUTH) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_EAST)))
         return FALSE;
     }
   else if (edge != GDK_WINDOW_EDGE_NORTH &&
@@ -1782,22 +1816,30 @@ edge_under_coordinates (GtkWindow     *window,
     {
       if (edge != GDK_WINDOW_EDGE_NORTH_WEST &&
           edge != GDK_WINDOW_EDGE_NORTH &&
-          edge != GDK_WINDOW_EDGE_NORTH_EAST)
+          edge != GDK_WINDOW_EDGE_NORTH_EAST &&
+          edge != GDK_WINDOW_EDGE_EAST &&
+          edge != GDK_WINDOW_EDGE_WEST)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_TOP_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_EAST ||
+           edge == GDK_WINDOW_EDGE_WEST) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_NORTH)))
         return FALSE;
     }
   else if (y > allocation.y + allocation.height - border.bottom - handle_v)
     {
       if (edge != GDK_WINDOW_EDGE_SOUTH_WEST &&
           edge != GDK_WINDOW_EDGE_SOUTH &&
-          edge != GDK_WINDOW_EDGE_SOUTH_EAST)
+          edge != GDK_WINDOW_EDGE_SOUTH_EAST &&
+          edge != GDK_WINDOW_EDGE_EAST &&
+          edge != GDK_WINDOW_EDGE_WEST)
         return FALSE;
 
       if (supports_edge_constraints &&
-          !(priv->edge_constraints & GDK_WINDOW_STATE_BOTTOM_RESIZABLE))
+          (edge == GDK_WINDOW_EDGE_EAST ||
+           edge == GDK_WINDOW_EDGE_WEST) &&
+          (priv->edge_constraints & constraints_for_edge (GDK_WINDOW_EDGE_SOUTH)))
         return FALSE;
     }
   else if (edge != GDK_WINDOW_EDGE_WEST &&