[gnome-system-monitor] Do not set gnome_version if one of the version numbers can not be read.

[Chris KÃhl <chriskuehl src gnome org>]

commit 9b3e48f0ef1131dfc827fb17d6cccb26ebde75c0
Author: Robert Roth <robert roth off gmail com>
Date:   Tue Nov 15 06:57:35 2011 +0200

    Do not set gnome_version if one of the version numbers can not be read.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=576863

 src/sysinfo.cpp |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/sysinfo.cpp b/src/sysinfo.cpp
index 0286752..f1cb7d6 100644
--- a/src/sysinfo.cpp
+++ b/src/sysinfo.cpp
@@ -201,8 +201,8 @@ namespace {
 
             xmlXPathFreeContext(context);
             xmlFreeDoc(document);
-
-            this->gnome_version = values[0] + '.' + values[1] + '.' + values[2];
+            if (!values[0].empty() && !values[1].empty() && !values[2].empty())
+                this->gnome_version = values[0] + '.' + values[1] + '.' + values[2];
         }
     };