[gthumb] image selector: fixed errors when not using the original image

[Paolo Bacchilega <paobac src gnome org>]

commit 1ed860d3b61362d4ddc189e851e8a88ebbed64bf
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sun Sep 22 10:36:41 2013 +0200

    image selector: fixed errors when not using the original image

 gthumb/gth-image-selector.c |   26 +++++++++++++++++++++++---
 1 files changed, 23 insertions(+), 3 deletions(-)
---
diff --git a/gthumb/gth-image-selector.c b/gthumb/gth-image-selector.c
index b012f00..53f1873 100644
--- a/gthumb/gth-image-selector.c
+++ b/gthumb/gth-image-selector.c
@@ -1535,6 +1535,20 @@ gth_image_selector_motion_notify (GthImageViewerTool *base,
 }
 
 
+static gboolean
+selection_is_valid (GthImageSelector *self)
+{
+       cairo_region_t *surface_region;
+       gboolean        valid;
+
+       surface_region = cairo_region_create_rectangle (&self->priv->surface_area);
+       valid = cairo_region_contains_rectangle (surface_region, &self->priv->selection_area) == 
CAIRO_REGION_OVERLAP_IN;
+       cairo_region_destroy (surface_region);
+
+       return valid;
+}
+
+
 static void
 gth_image_selector_image_changed (GthImageViewerTool *base)
 {
@@ -1550,10 +1564,16 @@ gth_image_selector_image_changed (GthImageViewerTool *base)
        }
 
        self->priv->surface = cairo_surface_reference (self->priv->surface);
-       self->priv->surface_area.width = cairo_image_surface_get_width (self->priv->surface);
-       self->priv->surface_area.height = cairo_image_surface_get_height (self->priv->surface);
+       if (! _cairo_image_surface_get_original_size (self->priv->surface,
+                                                     &self->priv->surface_area.width,
+                                                     &self->priv->surface_area.height))
+       {
+               self->priv->surface_area.width = cairo_image_surface_get_width (self->priv->surface);
+               self->priv->surface_area.height = cairo_image_surface_get_height (self->priv->surface);
+       }
 
-       init_selection (self);
+       if (! selection_is_valid (self))
+               init_selection (self);
 }