[Fixed] What we copy for repeated components

When the user provides an NxM panel we get N*M copies of the
components.
We need them to allow filters and stats to differentiate them.
But we don't need to deepcopy all the references, in particular:
- Parent sheet
- Project instance map
- Library symbol drawing

Fixes #842

Author: set-soft

kibot/kicad/v6_sch.py

@@ -1134,6 +1134,20 @@ def set_footprint(self, fp):
             raise SchError('Footprint with more than one colon (`{}`)'.format(fp))
         self.set_field('Footprint', fp)
 
+    def copy(self):
+        """ Make a deep copy, but not for all """
+        # Don't copy the links to projects, parent_sheet and library symbol
+        projects = self.projects
+        parent_sheet = self.parent_sheet
+        lib_symbol = self.lib_symbol
+        self.projects = self.parent_sheet = self.lib_symbol = None
+        # All the rest is copied
+        new_c = deepcopy(self)
+        new_c.projects = self.projects = projects
+        new_c.parent_sheet = self.parent_sheet = parent_sheet
+        new_c.lib_symbol = self.lib_symbol = lib_symbol
+        return new_c
+
     @staticmethod
     def get_lib_and_name(comp, i, name):
         comp.lib_id = comp.name = _check_str(i, 1, name+' lib_id')

kibot/kiplot.py

@@ -424,7 +424,7 @@ def get_board_comps_data(comps):
             comps.append(c)
         if c.has_pcb_info:
             # We already got this reference and filled the PCB info, this is another copy
-            c = deepcopy(c)
+            c = c.copy()
             comps.append(c)
         new_value = m.GetValue()
         if new_value != c.value and '${' not in c.value: