Optimized ExclusionConstraint.validate() a bit.

References to excluded fields are omitted in the replacement_map, so
there is no need to replace references before checking for exclusions.

1 files changed, 7 insertions, 8 deletions

diff --git a/django/contrib/postgres/constraints.py b/django/contrib/postgres/constraints.py
index f71a587430..c67292f9f0 100644
--- a/django/contrib/postgres/constraints.py
+++ b/django/contrib/postgres/constraints.py
@@ -202,16 +202,15 @@ class ExclusionConstraint(BaseConstraint):
         for idx, (expression, operator) in enumerate(self.expressions):
             if isinstance(expression, str):
                 expression = F(expression)
-            if isinstance(expression, F):
-                if exclude and expression.name in exclude:
-                    return
-                rhs_expression = expression.replace_references(replacement_map)
-            else:
-                rhs_expression = expression.replace_references(replacement_map)
-                if exclude:
-                    for expr in rhs_expression.flatten():
+            if exclude:
+                if isinstance(expression, F):
+                    if expression.name in exclude:
+                        return
+                else:
+                    for expr in expression.flatten():
                         if isinstance(expr, F) and expr.name in exclude:
                             return
+            rhs_expression = expression.replace_references(replacement_map)
             # Remove OpClass because it only has sense during the constraint
             # creation.
             if isinstance(expression, OpClass):