[gnome-builder] prefs: fix calculation of column height

[Christian Hergert <chergert src gnome org>]

commit e193dc0364412908f7409a3fbd7cb85dbead5e92
Author: Christian Hergert <chergert redhat com>
Date:   Thu Jan 28 23:00:27 2016 +0100

    prefs: fix calculation of column height
    
    If we have a sufficiently large child, it could cause the height
    calculation to assume that everything lands in one column.
    
    To avoid this, we require that a column always places at least one child
    in the column.

 libide/preferences/ide-preferences-flow-box.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/libide/preferences/ide-preferences-flow-box.c b/libide/preferences/ide-preferences-flow-box.c
index 041f21e..a0f8f4e 100644
--- a/libide/preferences/ide-preferences-flow-box.c
+++ b/libide/preferences/ide-preferences-flow-box.c
@@ -97,13 +97,14 @@ ide_preferences_flow_box_layout (IdePreferencesFlowBox *self,
   for (column = 0, i = 0; column < n_columns; column++)
     {
       GtkAllocation alloc;
+      gint j = 0;
 
       alloc.x = border_width + (COLUMN_WIDTH * column) + (column * COLUMN_SPACING);
       alloc.y = border_width;
       alloc.width = COLUMN_WIDTH;
       alloc.height = (height != 0) ? height : total_height / n_columns;
 
-      for (; i < self->children->len; i++)
+      for (; i < self->children->len; i++, j++)
         {
           IdePreferencesFlowBoxChild *child;
 
@@ -120,7 +121,7 @@ ide_preferences_flow_box_layout (IdePreferencesFlowBox *self,
            * If the child requisition is taller than the space we have left in
            * this column, we need to spill over to the next column.
            */
-          if (child->req.height > alloc.height && column < (n_columns - 1))
+          if ((j != 0) && (child->req.height > alloc.height) && (column < (n_columns - 1)))
             break;
 
           child->alloc.x = alloc.x;
@@ -170,7 +171,8 @@ ide_preferences_flow_box_get_preferred_width (GtkWidget *widget,
 
   border_width = gtk_container_get_border_width (GTK_CONTAINER (self));
 
-  *min_width = *nat_width = COLUMN_WIDTH + (border_width * 2);
+  *nat_width = (COLUMN_WIDTH * 3) + (COLUMN_SPACING * 2) + (border_width * 2);
+  *min_width = COLUMN_WIDTH + (border_width * 2);
 }
 
 static void