eo_facture: do not depend upon self.contrat for filename (#65103)

self.client is required but not self.contrat.

eo_gestion/eo_facture/models.py

@@ -29,7 +29,6 @@ from django.db.models import F, Q, Sum
 from django.db.models.query import QuerySet
 from django.db.models.signals import post_delete, post_save
 from django.template.loader import get_template
-from django.utils.encoding import force_text
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
 from weasyprint import HTML
@@ -381,7 +380,7 @@ class Facture(models.Model):
         pdf = html.write_pdf()
 
         if hasattr(settings, 'FACTURE_DIR'):
-            filename = os.path.join(settings.FACTURE_DIR, self.filename(add_client_name=True))
+            filename = os.path.join(settings.FACTURE_DIR, self.filename_with_client())
             with open(filename, 'wb') as fd:
                 fd.write(pdf)
         return pdf
@@ -435,12 +434,15 @@ class Facture(models.Model):
             payment.save()
         return facture_avoir
 
-    def filename(self, add_client_name=False):
-        return '%s%s%s.pdf' % (
-            self.code(),
-            '-%s' % force_text(self.contrat.client.nom) if add_client_name else '',
-            '-AVOIR' if self.annulation else '',
-        )
+    def filename(self):
+        avoir = '-AVOIR' if self.annulation else ''
+        filename = f'{self.code()}{avoir}.pdf'
+        return filename
+
+    def filename_with_client(self):
+        avoir = '-AVOIR' if self.annulation else ''
+        filename = f'{self.code()}-{self.client.nom}{avoir}.pdf'
+        return filename
 
     class Meta:
         ordering = ("-id",)