Handle directory entries in Archive Project

ZIP archives may have entries that are only directories.  We should not
try to extract this entries (they have no length); instead, we merely
create the path and continue

common/project/project_archiver.cpp

@@ -139,6 +139,10 @@ bool PROJECT_ARCHIVER::Unarchive( const wxString& aSrcFile, const wxString& aDes
             }
         }
 
+        // Directory entries need only be created, not extracted (0 size)
+        if( entry->IsDir() )
+            continue;
+
         wxTempFileOutputStream outputFileStream( fullname );
 
         if( CopyStreamData( *archiveStream, outputFileStream, entry->GetSize() ) )