[evolution/gnome-2-28] Bug 599882 - Crash in em_folder_tree_select_prev_path() when wrapping to bottom

[Matthew Barnes <mbarnes src gnome org>]

commit 91e0696b738ecc991f8b6c33442040de4fec1873
Author: Matthew Barnes <mbarnes redhat com>
Date:   Wed Oct 28 15:28:58 2009 -0400

    Bug 599882 - Crash in em_folder_tree_select_prev_path() when wrapping to bottom
    
    Also fixes a whole bunch of memory leaks caused by unfreed strings and
    unfreed GtkTreePaths.

 mail/em-folder-tree.c |  131 ++++++++++++++++++++++++++++++------------------
 1 files changed, 82 insertions(+), 49 deletions(-)
---
diff --git a/mail/em-folder-tree.c b/mail/em-folder-tree.c
index b13a47a..3c56967 100644
--- a/mail/em-folder-tree.c
+++ b/mail/em-folder-tree.c
@@ -2421,31 +2421,55 @@ em_folder_tree_select_next_path (EMFolderTree *emft, gboolean skip_read_folders)
 	return;
 }
 
-static GtkTreeIter
-get_last_child (GtkTreeModel *model, GtkTreeIter *iter)
-{
-	GtkTreeIter *child = g_new0 (GtkTreeIter, 1);
-	gboolean has_child = gtk_tree_model_iter_has_child (model, iter);
-
-	if (gtk_tree_model_iter_next (model, iter)) {
-		return get_last_child (model, iter);
-	} else if (has_child) {
-		/* Pick the last one */
-		gint nchildren = gtk_tree_model_iter_n_children (model, iter);
-		gtk_tree_model_iter_nth_child ( model, child, iter, nchildren-1);
-		return get_last_child (model, child);
+static gboolean
+folder_tree_descend (GtkTreeModel *model,
+                     GtkTreeIter *iter,
+                     GtkTreeIter *root)
+{
+	GtkTreeIter parent;
+	gint n_children;
+
+	/* Finds the rightmost descendant of the given root. */
+
+	if (root == NULL) {
+		n_children = gtk_tree_model_iter_n_children (model, NULL);
+
+		/* This will invalidate the iterator and return FALSE. */
+		if (n_children == 0)
+			return gtk_tree_model_get_iter_first (model, iter);
+
+		gtk_tree_model_iter_nth_child (
+			model, &parent, NULL, n_children - 1);
+	} else
+		parent = *root;
+
+	n_children = gtk_tree_model_iter_n_children (model, &parent);
+
+	while (n_children > 0) {
+		GtkTreeIter child;
+
+		gtk_tree_model_iter_nth_child (
+			model, &child, &parent, n_children - 1);
+
+		parent = child;
+
+		n_children = gtk_tree_model_iter_n_children (model, &parent);
 	}
 
-	return *iter;
+	*iter = parent;
+
+	return TRUE;
 }
 
 void
-em_folder_tree_select_prev_path (EMFolderTree *emft, gboolean skip_read_folders)
+em_folder_tree_select_prev_path (EMFolderTree *folder_tree,
+                                 gboolean skip_read_folders)
 {
 	GtkTreeSelection *selection;
 	GtkTreeModel *model;
-	GtkTreeIter iter, child;
-	GtkTreePath *path = NULL, *current_path = NULL;
+	GtkTreePath *path = NULL;
+	GtkTreePath *sentinel;
+	GtkTreeIter iter;
 	guint unread = 0;
 	struct _EMFolderTreePrivate *priv = emft->priv;
 
@@ -2453,51 +2477,60 @@ em_folder_tree_select_prev_path (EMFolderTree *emft, gboolean skip_read_folders)
 
 	selection = gtk_tree_view_get_selection(emft->priv->treeview);
 
-	if (gtk_tree_selection_get_selected(selection, &model, &iter)) {
+	/* Nothing selected means nothing to do. */
+	if (!gtk_tree_selection_get_selected (selection, &model, &iter))
+		return;
+
+	/* This prevents us from looping over the model indefinitely,
+	 * looking for unread messages when there are none. */
+	sentinel = gtk_tree_model_get_path (model, &iter);
+
+	do {
+		GtkTreeIter descendant;
+
+		if (path != NULL)
+			gtk_tree_path_free (path);
 
-		current_path = gtk_tree_model_get_path (model, &iter);
-		do {
 		path = gtk_tree_model_get_path (model, &iter);
-		if (!gtk_tree_path_prev (path)) {
+
+		if (gtk_tree_path_prev (path)) {
+			gtk_tree_model_get_iter (model, &iter, path);
+			folder_tree_descend (model, &descendant, &iter);
+
+			gtk_tree_path_free (path);
+			path = gtk_tree_model_get_path (model, &descendant);
+
+		} else if (gtk_tree_path_get_depth (path) > 1) {
 			gtk_tree_path_up (path);
 
-			if (!gtk_tree_path_compare (gtk_tree_path_new_first (), path))
-			{
-				gtk_tree_model_get_iter_first (model, &iter);
-				iter = get_last_child (model,&iter);
-				path = gtk_tree_model_get_path (model, &iter);
-			}
 		} else {
-			gtk_tree_model_get_iter (model, &iter, path);
-			if (gtk_tree_model_iter_has_child (model, &iter)) {
-				gint nchildren = gtk_tree_model_iter_n_children (model, &iter);
-				gtk_tree_model_iter_nth_child ( model, &child, &iter, nchildren-1);
-				path = gtk_tree_model_get_path (model, &child);
-			}
-		}
+			folder_tree_descend (model, &descendant, NULL);
 
-		/* TODO : Flags here for better options */
-		gtk_tree_model_get_iter_from_string (model, &iter, gtk_tree_path_to_string (path) );
+			gtk_tree_path_free (path);
+			path = gtk_tree_model_get_path (model, &descendant);
+		}
 
+		gtk_tree_model_get_iter (model, &iter, path);
 		gtk_tree_model_get (model, &iter, COL_UINT_UNREAD, &unread, -1);
 
-		} while (skip_read_folders && unread <=0 && gtk_tree_path_compare (current_path, path));
-	}
+	} while (skip_read_folders && unread <= 0 &&
+		gtk_tree_path_compare (path, sentinel) != 0);
 
-	if (path) {
-		if (!gtk_tree_view_row_expanded (priv->treeview, path)) {
-			gtk_tree_view_expand_to_path (priv->treeview, path);
-		}
+	if (!gtk_tree_view_row_expanded (tree_view, path))
+		gtk_tree_view_expand_to_path (tree_view, path);
 
-		gtk_tree_selection_select_path(selection, path);
+	gtk_tree_selection_select_path (selection, path);
 
-		if (!priv->cursor_set) {
-			gtk_tree_view_set_cursor (priv->treeview, path, NULL, FALSE);
-			priv->cursor_set = TRUE;
-		}
-		gtk_tree_view_scroll_to_cell (priv->treeview, path, NULL, TRUE, 0.5f, 0.0f);
+	if (!priv->cursor_set) {
+		gtk_tree_view_set_cursor (tree_view, path, NULL, FALSE);
+		priv->cursor_set = TRUE;
 	}
-	return;
+
+	gtk_tree_view_scroll_to_cell (
+		tree_view, path, NULL, TRUE, 0.5f, 0.0f);
+
+	gtk_tree_path_free (sentinel);
+	gtk_tree_path_free (path);
 }
 
 gchar *