[gnumeric] avoid null pointer on incomplete ODF file

[Andreas J. Guelzow <guelzow src gnome org>]

commit c65d21af39684bfdafbedf3a8828ca1c2ddfac1a
Author: Andreas J Guelzow <aguelzow pyrshep ca>
Date:   Sat Sep 18 10:08:13 2010 -0600

    avoid null pointer on incomplete ODF file
    
    2010-09-18  Andreas J. Guelzow <aguelzow pyrshep ca>
    
    	* openoffice-read.c (odf_created_by_gnumeric): avoid null pointer
    	  on incomplete ODF file.

 plugins/openoffice/ChangeLog         |    5 +++++
 plugins/openoffice/openoffice-read.c |    9 ++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)
---
diff --git a/plugins/openoffice/ChangeLog b/plugins/openoffice/ChangeLog
index 91be555..7108e5a 100644
--- a/plugins/openoffice/ChangeLog
+++ b/plugins/openoffice/ChangeLog
@@ -1,5 +1,10 @@
 2010-09-18  Andreas J. Guelzow <aguelzow pyrshep ca>
 
+	* openoffice-read.c (odf_created_by_gnumeric): avoid null pointer
+	  on incomplete ODF file.
+
+2010-09-18  Andreas J. Guelzow <aguelzow pyrshep ca>
+
 	* openoffice-read.c (odf_created_by_gnumeric): new
 	(openoffice_file_open): set saveinfo
 
diff --git a/plugins/openoffice/openoffice-read.c b/plugins/openoffice/openoffice-read.c
index 1f1e30a..5e44a95 100644
--- a/plugins/openoffice/openoffice-read.c
+++ b/plugins/openoffice/openoffice-read.c
@@ -6868,9 +6868,12 @@ odf_created_by_gnumeric (OOParseState *state)
 	GsfDocMetaData *meta_data = go_doc_get_meta_data (GO_DOC (state->pos.wb));
 	GsfDocProp *prop = gsf_doc_meta_data_lookup  (meta_data,
 						      "meta:generator");
-	char const *str = g_value_get_string (gsf_doc_prop_get_val (prop));
-	gboolean res = g_str_has_prefix (str, "gnumeric");
-	return res;
+	char const *str;
+
+	return (prop != NULL && 
+		(NULL != (str = g_value_get_string 
+			  (gsf_doc_prop_get_val (prop)))) &&
+		g_str_has_prefix (str, "gnumeric"));
 }
 
 static gboolean