Fix loading old (2007) symbol cache library files.

(cherry picked from commit f5186da1e5)

eeschema/dialogs/dialog_symbol_remap.cpp

@@ -471,6 +471,27 @@ bool DIALOG_SYMBOL_REMAP::backupProject( REPORTER& aReporter )
             errorMsg += tmp;
         }
 
+        // Back up the old (2007) cache library.
+        srcFileName.SetPath( Prj().GetProjectPath() );
+        srcFileName.SetName( Prj().GetProjectName() + wxS( ".cache" ) );
+        srcFileName.SetExt( FILEEXT::LegacySymbolLibFileExtension );
+
+        destFileName = srcFileName;
+        destFileName.SetName( destFileName.GetName() + timeStamp );
+        destFileName.AppendDir( backupFolder );
+
+        aReporter.Report( wxString::Format( _( "Backing up file '%s' to '%s'." ),
+                                            srcFileName.GetFullPath(),
+                                            destFileName.GetFullPath() ),
+                          RPT_SEVERITY_INFO );
+
+        if( srcFileName.Exists()
+                && !wxCopyFile( srcFileName.GetFullPath(), destFileName.GetFullPath() ) )
+        {
+            errorMsg += wxString::Format( _( "Failed to back up file '%s'.\n" ),
+                                          srcFileName.GetFullPath() );
+        }
+
         // Back up the rescue symbol library if it exists.
         srcFileName.SetName( Prj().GetProjectName() + wxS( "-rescue" ) );
         destFileName.SetName( srcFileName.GetName() + timeStamp );

eeschema/symbol_library.cpp

@@ -485,13 +485,20 @@ void SYMBOL_LIBS::SetLibNamesAndPaths( PROJECT* aProject, const wxString& aPaths
 
 const wxString SYMBOL_LIBS::CacheName( const wxString& aFullProjectFilename )
 {
-    wxFileName  name = aFullProjectFilename;
+    wxFileName filename( aFullProjectFilename );
+    wxString   name = filename.GetName();
 
-    name.SetName( name.GetName() + "-cache" );
-    name.SetExt( FILEEXT::LegacySymbolLibFileExtension );
+    filename.SetName( name + "-cache" );
+    filename.SetExt( FILEEXT::LegacySymbolLibFileExtension );
 
-    if( name.FileExists() )
-        return name.GetFullPath();
+    if( filename.FileExists() )
+        return filename.GetFullPath();
+
+    // Try the old (2007) cache name
+    filename.SetName( name + ".cache" );
+
+    if( filename.FileExists() )
+        return filename.GetFullPath();
 
     return wxEmptyString;
 }