Pcbnew footprint library table fixes.

* Make footprint editor work properly with library table.
* Fix bug in Eagle plugin when comparing file timestamps.
* Fix bug in footprint viewer when error occur loading footprints from
  the selected library.
* Fix error message display by in footprint viewer on library load error.

pcbnew/eagle_plugin.cpp

@@ -93,6 +93,9 @@ typedef boost::optional<double>             opt_double;
 typedef boost::optional<bool>               opt_bool;
 
 
+const wxChar* traceEaglePlugin = wxT( "KicadEaglePlugin" );
+
+
 /// segment (element) of our XPATH into the Eagle XML document tree in PTREE form.
 struct TRIPLET
 {
@@ -2731,15 +2734,17 @@ void EAGLE_PLUGIN::cacheLib( const wxString& aLibPath )
 {
     try
     {
-        wxDateTime  modtime;
+        wxDateTime  modtime = getModificationTime( aLibPath );
 
-        if( !m_mod_time.IsValid() )
-            m_mod_time.Now();
+        // Fixes assertions in wxWidgets debug builds for the wxDateTime object.  Refresh the
+        // cache if either of the wxDateTime objects are invalid or the last file modification
+        // time differs from the current file modification time.
+        bool load = !m_mod_time.IsValid() || !modtime.IsValid() ||
+                    m_mod_time != modtime;
 
-        if( aLibPath != m_lib_path ||
-            m_mod_time != ( modtime = getModificationTime( aLibPath ) ) )
+        if( aLibPath != m_lib_path || load )
         {
-            //D(printf("Loading '%s'\n", TO_UTF8( aLibPath ) );)
+            wxLogTrace( traceEaglePlugin, wxT( "Loading '%s'" ), TO_UTF8( aLibPath ) );
 
             PTREE       doc;
             LOCALE_IO   toggle;     // toggles on, then off, the C locale.

pcbnew/librairi.cpp

@@ -825,20 +825,10 @@ void FOOTPRINT_EDIT_FRAME::Select_Active_Library()
     wxString uri = m_footprintLibTable->FindRow( dlg.GetTextSelection() )->GetFullURI();
     wxFileName fileName = FP_LIB_TABLE::ExpandSubstitutions( uri );
 
-    if( fileName.IsOk() && fileName.FileExists() )
-    {
-        setLibPath( fileName.GetFullPath() );
-    }
-    else
-    {
-        wxString msg = wxString::Format( FMT_BAD_PATHS, GetChars( dlg.GetTextSelection() ) );
-
-        DisplayError( this, msg );
-
-        setLibNickName( wxEmptyString );
-        setLibPath( wxEmptyString );
-    }
+    wxLogDebug( wxT( "Loading footprint library <%s> from <%s>." ),
+                GetChars( dlg.GetTextSelection() ), GetChars( fileName.GetFullPath() ) );
 
+    setLibPath( fileName.GetFullPath() );
     updateTitle();
 }
 

pcbnew/loadcmp.cpp

@@ -511,7 +511,21 @@ wxString PCB_BASE_FRAME::SelectFootprint( EDA_DRAW_FRAME* aWindow,
         return wxEmptyString;
     }
 
-    MList.ReadFootprintFiles( libTable );
+    if( !MList.ReadFootprintFiles( libTable ) )
+    {
+        msg.Format( _( "Error occurred attempting to load footprint library <%s>:\n\n" ),
+                    GetChars( aLibraryFullFilename ) );
+
+        if( !MList.m_filesNotFound.IsEmpty() )
+            msg += _( "Files not found:\n\n" ) + MList.m_filesNotFound;
+
+        if( !MList.m_filesInvalid.IsEmpty() )
+            msg +=  _("\n\nFile load errors:\n\n" ) + MList.m_filesInvalid;
+
+        DisplayError( this, msg );
+        return wxEmptyString;
+    }
+
 #endif
 
     if( MList.GetCount() == 0 )

pcbnew/modview_frame.cpp

@@ -429,7 +429,6 @@ void FOOTPRINT_VIEWER_FRAME::ReCreateFootprintList()
     bool           libLoaded = false;
     FOOTPRINT_LIST fp_info_list;
     wxArrayString  libsList;
-    wxBusyCursor   busyCursor;
 
 #if !defined( USE_FP_LIB_TABLE )
     libsList.Add( m_libraryName );
@@ -453,11 +452,18 @@ void FOOTPRINT_VIEWER_FRAME::ReCreateFootprintList()
 
     if( !libLoaded )
     {
+        m_libraryName = wxEmptyString;
+
         wxString msg;
-        msg.Format( _( "Error occurred attempting to load footprint library <%s>:\n\n"
-                       "Files not found:\n\n%s\n\nFile load errors:\n\n%s" ),
-                    GetChars( m_libraryName ), GetChars( fp_info_list.m_filesNotFound ),
-                    GetChars( fp_info_list.m_filesInvalid ) );
+        msg.Format( _( "Error occurred attempting to load footprint library <%s>:\n\n" ),
+                    GetChars( m_libraryName ) );
+
+        if( !fp_info_list.m_filesNotFound.IsEmpty() )
+            msg += _( "Files not found:\n\n" ) + fp_info_list.m_filesNotFound;
+
+        if( !fp_info_list.m_filesInvalid.IsEmpty() )
+            msg +=  _("\n\nFile load errors:\n\n" ) + fp_info_list.m_filesInvalid;
+
         DisplayError( this, msg );
         return;
     }
@@ -502,6 +508,9 @@ void FOOTPRINT_VIEWER_FRAME::ClickOnLibList( wxCommandEvent& event )
 
 void FOOTPRINT_VIEWER_FRAME::ClickOnFootprintList( wxCommandEvent& event )
 {
+    if( m_FootprintList->GetCount() == 0 )
+        return;
+
     int ii = m_FootprintList->GetSelection();
 
     if( ii < 0 )