[gtk/fix-non-overlay-scrollbars-3] scrolledwindow: Always add other scrollbar size...

[Matthias Clasen <matthiasc src gnome org>]

commit 25879ea37e8918a28187dd382e7704051a38f011
Author: Timm Bäder <mail baedert org>
Date:   Mon Apr 19 14:42:29 2021 -0400

    scrolledwindow: Always add other scrollbar size...
    
    ... if we're not using indicators and the policy may be visible. Not
    doing this if the policy may be invisible is incorrect as we need to
    reserve the space anyway in case the scrolledwindow is allocated at
    minimum size and the child size increases to show the scrollbar.

 gtk/gtkscrolledwindow.c        | 30 ++++++++++++++++++++++++------
 testsuite/gtk/scrolledwindow.c |  4 ++--
 2 files changed, 26 insertions(+), 8 deletions(-)
---
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 1909077220..a931d2bad5 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -1900,10 +1900,19 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
    */
   if (policy_may_be_visible (priv->hscrollbar_policy))
     {
-      minimum_req.width = MAX (minimum_req.width, hscrollbar_requisition.width + sborder.left + 
sborder.right);
-      natural_req.width = MAX (natural_req.width, hscrollbar_requisition.width + sborder.left + 
sborder.right);
+      int vscrollbar_extra_size;
 
-      if (!priv->use_indicators && priv->hscrollbar_policy == GTK_POLICY_ALWAYS)
+      if (!priv->use_indicators && policy_may_be_visible (priv->vscrollbar_policy))
+        vscrollbar_extra_size = vscrollbar_requisition.width;
+      else
+        vscrollbar_extra_size = 0;
+
+      minimum_req.width = MAX (minimum_req.width,
+                               hscrollbar_requisition.width + sborder.left + sborder.right + 
vscrollbar_extra_size);
+      natural_req.width = MAX (natural_req.width,
+                               hscrollbar_requisition.width + sborder.left + sborder.right + 
vscrollbar_extra_size);
+
+      if (!priv->use_indicators)
        {
          minimum_req.height += scrollbar_spacing + hscrollbar_requisition.height;
          natural_req.height += scrollbar_spacing + hscrollbar_requisition.height;
@@ -1912,10 +1921,19 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
 
   if (policy_may_be_visible (priv->vscrollbar_policy))
     {
-      minimum_req.height = MAX (minimum_req.height, vscrollbar_requisition.height + sborder.top + 
sborder.bottom);
-      natural_req.height = MAX (natural_req.height, vscrollbar_requisition.height + sborder.top + 
sborder.bottom);
+      int hscrollbar_extra_size;
+
+      if (!priv->use_indicators && policy_may_be_visible (priv->hscrollbar_policy))
+        hscrollbar_extra_size = hscrollbar_requisition.height;
+      else
+        hscrollbar_extra_size = 0;
+
+      minimum_req.height = MAX (minimum_req.height,
+                                vscrollbar_requisition.height + sborder.top + sborder.bottom + 
hscrollbar_extra_size);
+      natural_req.height = MAX (natural_req.height,
+                                vscrollbar_requisition.height + sborder.top + sborder.bottom + 
hscrollbar_extra_size);
 
-      if (!priv->use_indicators && priv->vscrollbar_policy == GTK_POLICY_ALWAYS)
+      if (!priv->use_indicators)
        {
          minimum_req.width += scrollbar_spacing + vscrollbar_requisition.width;
          natural_req.width += scrollbar_spacing + vscrollbar_requisition.width;
diff --git a/testsuite/gtk/scrolledwindow.c b/testsuite/gtk/scrolledwindow.c
index c6093d8256..e141fe35ba 100644
--- a/testsuite/gtk/scrolledwindow.c
+++ b/testsuite/gtk/scrolledwindow.c
@@ -58,7 +58,7 @@ test_size (gboolean       overlay,
       /* If the relevant scrollbar is non-overlay and always shown, it is added
        * to the preferred size. When comparing to the expected size, we need to
        * to exclude that extra, as we are only interested in the content size */
-      if (!overlay && policy == GTK_POLICY_ALWAYS)
+      if (!overlay)
         {
           GtkWidget *scrollbar = gtk_scrolled_window_get_vscrollbar (GTK_SCROLLED_WINDOW (scrolledwindow));
           gtk_widget_get_preferred_width (scrollbar, &scrollbar_size, NULL);
@@ -87,7 +87,7 @@ test_size (gboolean       overlay,
           gtk_widget_get_preferred_height (box, &child_size, NULL);
         }
 
-      if (!overlay && policy == GTK_POLICY_ALWAYS)
+      if (!overlay)
         {
           GtkWidget *scrollbar = gtk_scrolled_window_get_hscrollbar (GTK_SCROLLED_WINDOW (scrolledwindow));
           gtk_widget_get_preferred_height (scrollbar, &scrollbar_size, NULL);