[MERGE] forward port branch 11.0 up to bb6f6c57f97

1 files changed, 27 insertions, 12 deletions

diff --git a/odoo/fields.py b/odoo/fields.py
index 39fe7825e30..d8efade6691 100644
--- a/odoo/fields.py
+++ b/odoo/fields.py
@@ -2054,6 +2054,26 @@ class Many2one(_Relational):
         return super(Many2one, self).convert_to_onchange(value, record, names)
 
 
+class _RelationalMultiUpdate(object):
+    """ A getter to update the value of an x2many field, without reading its
+        value until necessary.
+    """
+    __slots__ = ['record', 'field', 'value']
+
+    def __init__(self, record, field, value):
+        self.record = record
+        self.field = field
+        self.value = value
+
+    def __call__(self):
+        # determine the current field's value, and update it in cache only
+        record, field, value = self.record, self.field, self.value
+        cache = record.env.cache
+        cache.remove(record, field)
+        val = field.convert_to_cache(record[field.name] | value, record, validate=False)
+        cache.set(record, field, val)
+        return val
+
 
 class _RelationalMulti(_Relational):
     """ Abstract class for relational fields *2many. """
@@ -2065,21 +2085,16 @@ class _RelationalMulti(_Relational):
         """ Update the cached value of ``self`` for ``records`` with ``value``. """
         cache = records.env.cache
         for record in records:
-            if cache.contains(record, self):
+            special = cache.get_special(record, self)
+            if isinstance(special, _RelationalMultiUpdate):
+                # include 'value' in the existing _RelationalMultiUpdate; this
+                # avoids reading the field's value (which may be large)
+                special.value |= value
+            elif cache.contains(record, self):
                 val = self.convert_to_cache(record[self.name] | value, record, validate=False)
                 cache.set(record, self, val)
             else:
-                cache.set_special(record, self, self._update_getter(record, value))
-
-    def _update_getter(self, record, value):
-        def getter():
-            # determine the current field's value, and update it in cache only
-            cache = record.env.cache
-            cache.remove(record, self)
-            val = self.convert_to_cache(record[self.name] | value, record, validate=False)
-            cache.set(record, self, val)
-            return val
-        return getter
+                cache.set_special(record, self, _RelationalMultiUpdate(record, self, value))
 
     def convert_to_cache(self, value, record, validate=True):
         # cache format: tuple(ids)