Reduce the clauses of child-of using common roots

For the path, if the longer path contains another searched path, we can ignore
it.
For MPTT, if a range is inside a larger range, we can also ignore it.

Closes #14064

trytond/trytond/model/fields/many2one.py

@@ -5,6 +5,7 @@ import warnings
 from sql import As, Column, Expression, Literal, Null, Query, With
 from sql.aggregate import Max
 from sql.conditionals import Coalesce
+from sql.functions import CharLength
 from sql.operators import Or
 
 from trytond.config import config
@@ -134,10 +135,20 @@ class Many2One(Field):
         Target = self.get_target()
         path_column = getattr(Target, self.path).sql_column(table)
         path_column = Coalesce(path_column, '')
-        cursor.execute(*table.select(path_column, where=red_sql))
+        cursor.execute(*table.select(
+                path_column, where=red_sql,
+                order_by=[CharLength(path_column).desc, path_column.asc]))
         if operator.endswith('child_of'):
-            where = Or()
+            paths = set()
             for path, in cursor:
+                discard = set()
+                for opath in paths:
+                    if path in opath:
+                        discard.add(opath)
+                paths -= discard
+                paths.add(path)
+            where = Or()
+            for path in paths:
                 where.append(path_column.like(path + '%'))
         else:
             ids = [int(x) for path, in cursor for x in path.split('/')[:-1]]
@@ -156,9 +167,19 @@ class Many2One(Field):
         Target = self.get_target()
         left = getattr(Target, self.left).sql_column(table)
         right = getattr(Target, self.right).sql_column(table)
-        cursor.execute(*table.select(left, right, where=red_sql))
-        where = Or()
+        cursor.execute(*table.select(
+                left, right, where=red_sql,
+                order_by=[(right - left).asc, left.asc]))
+        ranges = set()
         for l, r in cursor:
+            discard = set()
+            for ol, or_ in ranges:
+                if l < ol and or_ < r:
+                    discard.add((ol, or_))
+            ranges -= discard
+            ranges.add((l, r))
+        where = Or()
+        for l, r in ranges:
             if operator.endswith('child_of'):
                 where.append((left >= l) & (right <= r))
             else:

trytond/trytond/tests/test_field_many2one.py

@@ -400,6 +400,21 @@ class FieldMany2OneTreeTestCase(TestCase):
                     self.first1, self.first2, self.first3, self.first4,
                     self.second2, self.second3, self.second4]))
 
+    @with_transaction()
+    def test_search_child_of_first1_second1(self):
+        "Test search many2one child of first1 and second1"
+        Many2One = Pool().get(self.model_name)
+        self.create_tree(Many2One)
+
+        result = Many2One.search([
+                ('many2one', 'child_of',
+                    [self.first1.id, self.second1.id]),
+                ])
+
+        self.assertListEqual(
+            sorted(result),
+            sorted([self.first1, self.second1, self.second2]))
+
     @with_transaction()
     def test_search_child_of_empty(self):
         "Test search many2one child of empty"