[4.0.x] Fixed #33335 -- Made model validation ignore functional unique constraints.

Regression in 3aa545281e0c0f9fac93753e3769df9e0334dbaa.

Thanks Hervé Le Roy for the report.

Backport of 1eaf38fa87384fe26d1abf6e389d6df1600d4d8c from main

1 files changed, 6 insertions, 4 deletions

diff --git a/docs/ref/models/constraints.txt b/docs/ref/models/constraints.txt
index c675903db6..dd49b1cafc 100644
--- a/docs/ref/models/constraints.txt
+++ b/docs/ref/models/constraints.txt
@@ -35,10 +35,12 @@ option.
     not raise ``ValidationError``\s. Rather you'll get a database integrity
     error on ``save()``. ``UniqueConstraint``\s without a
     :attr:`~UniqueConstraint.condition` (i.e. non-partial unique constraints)
-    are different in this regard, in that they leverage the existing
-    ``validate_unique()`` logic, and thus enable two-stage validation. In
-    addition to ``IntegrityError`` on ``save()``, ``ValidationError`` is also
-    raised during model validation when the ``UniqueConstraint`` is violated.
+    and :attr:`~UniqueConstraint.expressions` (i.e. non-functional unique
+    constraints) are different in this regard, in that they leverage the
+    existing ``validate_unique()`` logic, and thus enable two-stage validation.
+    In addition to ``IntegrityError`` on ``save()``, ``ValidationError`` is
+    also raised during model validation when the ``UniqueConstraint`` is
+    violated.
 
 ``CheckConstraint``
 ===================