Fixed #37075 -- Allowed overriding the PostgreSQL pool's "check" callable.HEADmain

Setting "check" in OPTIONS["pool"] previously raised TypeError because the
PostgreSQL backend always passed check= to ConnectionPool() and unpacked
**pool_options on top, regardless of CONN_HEALTH_CHECKS. The user's callable
now takes precedence via setdefault(); pool_options is copied first to avoid
mutating the user's settings dict.

1 files changed, 5 insertions, 1 deletions

diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 42b37ab3c2..16cf7f84e6 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -216,11 +216,15 @@ class DatabaseWrapper(BaseDatabaseWrapper):
             # Ensure we run in autocommit, Django properly sets it later on.
             connect_kwargs["autocommit"] = True
             enable_checks = self.settings_dict["CONN_HEALTH_CHECKS"]
+            # Copy to avoid mutating the user's settings dict.
+            pool_options = {**pool_options}
+            pool_options.setdefault(
+                "check", ConnectionPool.check_connection if enable_checks else None
+            )
             pool = ConnectionPool(
                 kwargs=connect_kwargs,
                 open=False,  # Do not open the pool during startup.
                 configure=self._configure_connection,
-                check=ConnectionPool.check_connection if enable_checks else None,
                 **pool_options,
             )
             # setdefault() ensures that multiple threads don't set this in