ensure correlate_except is checked for empty tuple

Fixed issue where :meth:`_sql.Select.correlate_except` method, when passed
either the ``None`` value or no arguments, would not correlate any elements
when used in an ORM context (that is, passing ORM entities as FROM
clauses), rather than causing all FROM elements to be considered as
"correlated" in the same way which occurs when using Core-only constructs.

Fixes: #7514
Change-Id: Ic4a5252c8f3c1140aba6c308264948f3a91f33f5
(cherry picked from commit 709239f4a61e88c2051dce87eb4058efd653697e)

1 files changed, 8 insertions, 0 deletions

diff --git a/test/sql/test_compiler.py b/test/sql/test_compiler.py
index eeb102162..50fd582b7 100644
--- a/test/sql/test_compiler.py
+++ b/test/sql/test_compiler.py
@@ -5902,6 +5902,14 @@ class CorrelateTest(fixtures.TestBase, AssertsCompiledSQL):
             )
         )
 
+    def test_correlate_except_empty(self):
+        t1, t2, s1 = self._fixture()
+        self._assert_where_all_correlated(
+            select(t1, t2).where(
+                t2.c.a == s1.correlate_except().scalar_subquery()
+            )
+        )
+
     def test_correlate_except_having(self):
         t1, t2, s1 = self._fixture()
         self._assert_having_correlated(