More potential crash fixes.

src/backend/metadata.cpp

@@ -148,7 +148,12 @@ namespace boss {
                 const std::string& condition) : _type(type), _content(content), ConditionStruct(condition) {}
 
     bool Message::operator < (const Message& rhs) const {
-        return boost::ilexicographical_compare(_content.front().Str(), rhs.Content().front().Str());
+        if (!_content.empty() && !rhs.Content().empty())
+            return boost::ilexicographical_compare(_content.front().Str(), rhs.Content().front().Str());
+        else if (_content.empty())
+            return true;
+        else
+            return false;
     }
 
     bool Message::operator == (const Message& rhs) const {
@@ -392,8 +397,7 @@ namespace boss {
     }
 
     Plugin Plugin::DiffMetadata(const Plugin& plugin) const {
-        Plugin p(name);
-        p.Priority(priority);
+        Plugin p(*this);
 
         //Compare this plugin against the given plugin.
         set<File> files = plugin.LoadAfter();

src/gui/main.cpp

@@ -668,12 +668,16 @@ void Launcher::OnSortPlugins(wxCommandEvent& event) {
             BOOST_LOG_TRIVIAL(trace) << "Building list of edited plugins.";
             for (list<boss::Plugin>::iterator it=newPluginsList.begin(),endit=newPluginsList.end(); it != endit; ++it) {
                 list<boss::Plugin>::const_iterator jt = find(plugins.begin(), plugins.end(), *it);
+
+                if (jt == plugins.end())
+                    continue;
+
                 boss::Plugin diff = it->DiffMetadata(*jt);
 
                 if (!diff.HasNameOnly())
                     editedPlugins.push_back(diff);
             }
-            plugins = newPluginsList;
+            plugins.swap(newPluginsList);
 
             if (!editedPlugins.empty()) {
 
@@ -1109,6 +1113,9 @@ std::list<boss::Plugin> LoadOrderPreview::GetLoadOrder() const {
 
         list<boss::Plugin>::const_iterator it = find(_plugins.begin(), _plugins.end(), boss::Plugin(name));
 
+        if (it == _plugins.end())
+            continue;
+
         plugins.push_back(*it);
 
         if (wasMovedUp) {