From: Daniele Varrazzo <daniele.varrazzo@gmail.com>
Date: Wed, 10 Feb 2021 02:04:00 +0000 (+0100)
Subject: Close correctly named cursors in corner cases
X-Git-Tag: 3.0.dev0~115^2~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8e4eb2a240612d36f85e322fa6fec2660aa1dd9;p=thirdparty%2Fpsycopg.git

Close correctly named cursors in corner cases
---

diff --git a/psycopg3/psycopg3/named_cursor.py b/psycopg3/psycopg3/named_cursor.py
index 434901f9b..6e6ec71ee 100644
--- a/psycopg3/psycopg3/named_cursor.py
+++ b/psycopg3/psycopg3/named_cursor.py
@@ -60,6 +60,16 @@ class NamedCursorHelper(Generic[ConnectionType]):
         self.described = True
 
     def _close_gen(self, cur: BaseCursor[ConnectionType]) -> PQGen[None]:
+        # if we didn't declare the cursor ourselves we still have to close it
+        # but we must make sure it exists.
+        if not self.described:
+            query = sql.SQL(
+                "select 1 from pg_catalog.pg_cursors where name = {}"
+            ).format(sql.Literal(self.name))
+            res = yield from cur._conn._exec_command(query)
+            if res.ntuples == 0:
+                return
+
         query = sql.SQL("close {}").format(sql.Identifier(self.name))
         yield from cur._conn._exec_command(query)
 
diff --git a/tests/test_named_cursor.py b/tests/test_named_cursor.py
index 4b142dd95..e3bbca10a 100644
--- a/tests/test_named_cursor.py
+++ b/tests/test_named_cursor.py
@@ -31,6 +31,12 @@ def test_close(conn, recwarn):
     assert not recwarn
 
 
+def test_close_noop(conn, recwarn):
+    cur = conn.cursor("foo")
+    cur.close()
+    assert not recwarn
+
+
 def test_context(conn, recwarn):
     with conn.cursor("foo") as cur:
         cur.execute("select generate_series(1, 10) as bar")
@@ -170,12 +176,21 @@ def test_non_scrollable(conn):
 
 def test_steal_cursor(conn):
     cur1 = conn.cursor()
-    cur1.execute(
-        "declare test cursor without hold for select generate_series(1, 6)"
-    )
+    cur1.execute("declare test cursor for select generate_series(1, 6)")
 
     cur2 = conn.cursor("test")
     # can call fetch without execute
     assert cur2.fetchone() == (1,)
     assert cur2.fetchmany(3) == [(2,), (3,), (4,)]
     assert cur2.fetchall() == [(5,), (6,)]
+
+
+def test_stolen_cursor_close(conn):
+    cur1 = conn.cursor()
+    cur1.execute("declare test cursor for select generate_series(1, 6)")
+    cur2 = conn.cursor("test")
+    cur2.close()
+
+    cur1.execute("declare test cursor for select generate_series(1, 6)")
+    cur2 = conn.cursor("test")
+    cur2.close()
diff --git a/tests/test_named_cursor_async.py b/tests/test_named_cursor_async.py
index 3a2a07843..0ae150229 100644
--- a/tests/test_named_cursor_async.py
+++ b/tests/test_named_cursor_async.py
@@ -33,6 +33,12 @@ async def test_close(aconn, recwarn):
     assert not recwarn
 
 
+async def test_close_noop(aconn, recwarn):
+    cur = await aconn.cursor("foo")
+    await cur.close()
+    assert not recwarn
+
+
 async def test_context(aconn, recwarn):
     async with await aconn.cursor("foo") as cur:
         await cur.execute("select generate_series(1, 10) as bar")