[gtk+] scrolled window: Fix scrollbar size allocation

[Matthias Clasen <matthiasc src gnome org>]

commit 5f00a9b4ec52abfa60281df1903430caaff5ac42
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Mar 11 21:40:02 2016 -0500

    scrolled window: Fix scrollbar size allocation
    
    We were not taking the scrollable borders into account when
    requesting size for the scrolled window, which could lead
    to underallocating the scrollbars at size allocation time
    when we *did* take the borders into account.
    
    This is most notable with treeviews, where we have the
    headers as borders, and was causing the treeview-crash-too-wide
    reftest to fail.

 gtk/gtkscrolledwindow.c |   27 ++++++++++++++++-----------
 1 files changed, 16 insertions(+), 11 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 3b62519..f9fa7ea 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -1715,6 +1715,7 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
   GtkRequisition minimum_req, natural_req;
   GtkWidget *child;
   gint min_child_size, nat_child_size;
+  GtkBorder border = { 0 };
 
   scrollbar_spacing = _gtk_scrolled_window_get_scrollbar_spacing (scrolled_window);
 
@@ -1731,6 +1732,10 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
                                  &vscrollbar_requisition, NULL);
 
   child = gtk_bin_get_child (bin);
+
+  if (GTK_IS_SCROLLABLE (child))
+    gtk_scrollable_get_border (GTK_SCROLLABLE (child), &border);
+
   if (child && gtk_widget_get_visible (child))
     {
       if (orientation == GTK_ORIENTATION_HORIZONTAL)
@@ -1787,19 +1792,21 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
        }
     }
 
-  if (policy_may_be_visible (priv->hscrollbar_policy) && !priv->use_indicators)
+  if (policy_may_be_visible (priv->hscrollbar_policy))
     {
-      minimum_req.width = MAX (minimum_req.width, hscrollbar_requisition.width);
-      natural_req.width = MAX (natural_req.width, hscrollbar_requisition.width);
-      if (!extra_height || priv->hscrollbar_policy == GTK_POLICY_ALWAYS)
+      minimum_req.width = MAX (minimum_req.width, hscrollbar_requisition.width + border.left + border.right);
+      natural_req.width = MAX (natural_req.width, hscrollbar_requisition.width + border.left + border.right);
+      if (!priv->use_indicators &&
+          (!extra_height || priv->hscrollbar_policy == GTK_POLICY_ALWAYS))
        extra_height = scrollbar_spacing + hscrollbar_requisition.height;
     }
 
-  if (policy_may_be_visible (priv->vscrollbar_policy) && !priv->use_indicators)
+  if (policy_may_be_visible (priv->vscrollbar_policy))
     {
-      minimum_req.height = MAX (minimum_req.height, vscrollbar_requisition.height);
-      natural_req.height = MAX (natural_req.height, vscrollbar_requisition.height);
-      if (!extra_width || priv->vscrollbar_policy == GTK_POLICY_ALWAYS)
+      minimum_req.height = MAX (minimum_req.height, vscrollbar_requisition.height + border.top + 
border.bottom);
+      natural_req.height = MAX (natural_req.height, vscrollbar_requisition.height + border.top + 
border.bottom);
+      if (!priv->use_indicators &&
+          (!extra_width || priv->vscrollbar_policy == GTK_POLICY_ALWAYS))
        extra_width = scrollbar_spacing + vscrollbar_requisition.width;
     }
 
@@ -2830,7 +2837,6 @@ gtk_scrolled_window_inner_allocation (GtkWidget     *widget,
   GtkBorder border = { 0 };
 
   gtk_scrolled_window_relative_allocation (widget, rect);
-
   child = gtk_bin_get_child (GTK_BIN (widget));
   if (GTK_IS_SCROLLABLE (child) &&
       gtk_scrollable_get_border (GTK_SCROLLABLE (child), &border))
@@ -3030,8 +3036,7 @@ gtk_scrolled_window_relative_allocation (GtkWidget     *widget,
   gtk_widget_get_preferred_height (priv->hscrollbar, &sb_height, NULL);
   gtk_widget_get_preferred_width (priv->vscrollbar, &sb_width, NULL);
 
-  gtk_css_gadget_get_content_allocation (priv->gadget, &content_allocation,
-                                         NULL);
+  gtk_css_gadget_get_content_allocation (priv->gadget, &content_allocation, NULL);
 
   allocation->x = content_allocation.x;
   allocation->y = content_allocation.y;