[gthumb] fixed drag and drop with the middle mouse button

[Paolo Bacchilega <paobac src gnome org>]

commit 507b7174efebb25f305b4bddaaa27815bf8edaa7
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Tue Feb 7 20:07:09 2012 +0100

    fixed drag and drop with the middle mouse button

 gthumb/gth-browser.c   |    4 ++--
 gthumb/gth-grid-view.c |   13 +++++++++----
 2 files changed, 11 insertions(+), 6 deletions(-)
---
diff --git a/gthumb/gth-browser.c b/gthumb/gth-browser.c
index fff9633..2d1636e 100644
--- a/gthumb/gth-browser.c
+++ b/gthumb/gth-browser.c
@@ -3380,7 +3380,7 @@ gth_file_list_button_press_cb  (GtkWidget      *widget,
 		}
 		gth_file_list_popup_menu (browser, event);
 
-		return TRUE;
+		return FALSE;
 	}
 	else if ((event->type == GDK_BUTTON_PRESS) && (event->button == 2)) {
 		GtkWidget *file_view;
@@ -3393,7 +3393,7 @@ gth_file_list_button_press_cb  (GtkWidget      *widget,
 			gth_file_selection_select (GTH_FILE_SELECTION (file_view), pos);
 			gth_file_view_set_cursor (GTH_FILE_VIEW (file_view), pos);
 		}
-		return TRUE;
+		return FALSE;
 	}
 	else if ((event->type == GDK_2BUTTON_PRESS) && (event->button == 2)) {
 		gth_browser_fullscreen (browser);
diff --git a/gthumb/gth-grid-view.c b/gthumb/gth-grid-view.c
index ecec1a4..31a5a8a 100644
--- a/gthumb/gth-grid-view.c
+++ b/gthumb/gth-grid-view.c
@@ -2695,10 +2695,15 @@ gth_grid_view_button_press (GtkWidget      *widget,
 	else if ((pos != -1) && (event->button == 1) && (event->type == GDK_BUTTON_PRESS)) {
 		/* This can be the start of a dragging action. */
 
-		self->priv->dragging = TRUE;
-		self->priv->drag_button = 1;
-		self->priv->drag_start_x = event->x;
-		self->priv->drag_start_y = event->y;
+		if (! (event->state & GDK_CONTROL_MASK)
+		    && ! (event->state & GDK_SHIFT_MASK)
+		    && self->priv->drag_source_enabled)
+		{
+			self->priv->dragging = TRUE;
+			self->priv->drag_button = 1;
+			self->priv->drag_start_x = event->x;
+			self->priv->drag_start_y = event->y;
+		}
 
 		if (self->priv->selection_mode != GTK_SELECTION_NONE) {
 			GthGridViewItem *item;