Add uninstall hook to avoid garbage images hanging around after submodule is uninstalled.

base_multi_image/README.rst

@@ -57,18 +57,26 @@ To develop a module based on this one:
 
 * If the model you are extending already had an image field, and you want to
   trick Odoo to make those images to multi-image mode, you will need to make
-  use of the provided :meth:`~.hooks.pre_init_hook_for_submodules`, like
-  the ``product_multi_image`` module does::
+  use of the provided :meth:`~.hooks.pre_init_hook_for_submodules` and
+  :meth:`~.hooks.uninstall_hook_for_submodules`, like the
+  ``product_multi_image`` module does::
 
     from openerp.addons.base_multi_image.hooks import \
         pre_init_hook_for_submodules
 
 
     def pre_init_hook(cr):
+        """Transform single into multi images."""
         pre_init_hook_for_submodules(cr, "product.template", "image")
         pre_init_hook_for_submodules(cr, "product.product", "image_variant")
 
 
+    def uninstall_hook(cr, registry):
+        """Remove multi images for models that no longer use them."""
+        uninstall_hook_for_submodules(cr, registry, "product.template")
+        uninstall_hook_for_submodules(cr, registry, "product.product")
+
+
 .. image:: https://odoo-community.org/website/image/ir.attachment/5784_f2813bd/datas
    :alt: Try me on Runbot
    :target: https://runbot.odoo-community.org/runbot/149/9.0

base_multi_image/hooks.py

@@ -59,6 +59,24 @@ def pre_init_hook_for_submodules(cr, model, field):
         )
 
 
+def uninstall_hook_for_submodules(cr, registry, model):
+    """Remove multi-images for a given model.
+
+    :param openerp.sql_db.Cursor cr:
+        Database cursor.
+
+    :param openerp.modules.registry.RegistryManager registry:
+        Database registry, using v7 api.
+
+    :param str model:
+        Model technical name, like "res.partner". All multi-images for that
+        model will be deleted
+    """
+    Image = registry["base_multi_image.image"]
+    ids = Image.search(cr, SUPERUSER_ID, [("owner_model", "=", model)])
+    Image.unlink(cr, SUPERUSER_ID, ids)
+
+
 def table_has_column(cr, table, field):
     query = """
         SELECT %(field)s