[FIX] survey: matrix results after row deletion

In a survey question of type `matrix`,
nothing prevents to remove a row from the matrix,
even if there are already answers for this line.

If the case happens, the row is deleted, but
not the answers. The answers are therefore orphan.
The answers should probably be deleted when the
row is removed from the survey, but this is a risky
change, and, even, users might want to keep track
of the answers given even if the line doesn't exist
anymore in the survey.

Therefore, we just handle the case when displaying
the survey results,
we ignore matrix answers for which the row no longer
exists.

opw-666393

addons/survey/survey.py

@@ -373,7 +373,7 @@ class survey_survey(osv.Model):
             for cell in product(rows.keys(), answers.keys()):
                 res[cell] = 0
             for input_line in question.user_input_line_ids:
-                if input_line.answer_type == 'suggestion' and (not(current_filters) or input_line.user_input_id.id in current_filters):
+                if input_line.answer_type == 'suggestion' and (not(current_filters) or input_line.user_input_id.id in current_filters) and input_line.value_suggested_row:
                     res[(input_line.value_suggested_row.id, input_line.value_suggested.id)] += 1
                 if input_line.answer_type == 'text' and (not(current_filters) or input_line.user_input_id.id in current_filters):
                     comments.append(input_line)