[dia] [scan-build] Null dereference (theoretical)

[Hans Breuer <hans src gnome org>]

commit 083899ad23176c1a50834038ac13dbbe26e73a55
Author: Hans Breuer <hans breuer org>
Date:   Sun Dec 6 18:15:11 2009 +0100

    [scan-build] Null dereference (theoretical)
    
    Add g_return_val_if_fail() check to keep scan-build happy.
    At least there is no point in calling load or save without data.

 app/load_save.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/app/load_save.c b/app/load_save.c
index f545fe6..399faa5 100644
--- a/app/load_save.c
+++ b/app/load_save.c
@@ -402,6 +402,7 @@ diagram_data_load(const char *filename, DiagramData *data, void* user_data)
   Layer *active_layer = NULL;
   GHashTable* unknown_objects_hash = g_hash_table_new(g_str_hash, g_str_equal);
 
+  g_return_val_if_fail(data!=NULL, FALSE);
 
   if (g_file_test (filename, G_FILE_TEST_IS_DIR)) {
     message_error(_("You must specify a file, not a directory.\n"));
@@ -837,6 +838,8 @@ diagram_data_write_doc(DiagramData *data, const char *filename)
   xmlNs *name_space;
   Diagram *diagram = DIA_IS_DIAGRAM (data) ? DIA_DIAGRAM (data) : NULL;
 
+  g_return_val_if_fail(data!=NULL, NULL);
+
   doc = xmlNewDoc((const xmlChar *)"1.0");
   doc->encoding = xmlStrdup((const xmlChar *)"UTF-8");
   doc->xmlRootNode = xmlNewDocNode(doc, NULL, (const xmlChar *)"diagram", NULL);