gh-125860: Skip separate-SCM_RIGHTS socket tests on NetBSD, OpenBSD and DragonFly (GH-154239)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: serhiy-storchaka

Lib/test/test_socket.py

@@ -55,6 +55,10 @@
 VSOCKPORT = 1234
 AIX = platform.system() == "AIX"
 SOLARIS = sys.platform.startswith("sunos")
+# NetBSD, OpenBSD and DragonFly deliver the file descriptors from only one
+# SCM_RIGHTS control message when several are sent in a single sendmsg().
+BSD_COMBINES_SCM_RIGHTS = sys.platform.startswith(
+    ("netbsd", "openbsd", "dragonfly"))
 WSL = "microsoft-standard-WSL" in platform.release()
 
 try:
@@ -4178,6 +4182,7 @@ def _testFDPassCMSG_LEN(self):
     @unittest.skipIf(is_apple, "skipping, see issue #12958")
     @unittest.skipIf(SOLARIS, "skipping, see gh-91214")
     @unittest.skipIf(AIX, "skipping, see issue #22397")
+    @unittest.skipIf(BSD_COMBINES_SCM_RIGHTS, "skipping, see gh-125860")
     @requireAttrs(socket, "CMSG_SPACE")
     def testFDPassSeparate(self):
         # Pass two FDs in two separate arrays.  Arrays may be combined
@@ -4190,6 +4195,7 @@ def testFDPassSeparate(self):
     @unittest.skipIf(is_apple, "skipping, see issue #12958")
     @unittest.skipIf(SOLARIS, "skipping, see gh-91214")
     @unittest.skipIf(AIX, "skipping, see issue #22397")
+    @unittest.skipIf(BSD_COMBINES_SCM_RIGHTS, "skipping, see gh-125860")
     def _testFDPassSeparate(self):
         fd0, fd1 = self.newFDs(2)
         self.assertEqual(
@@ -4204,6 +4210,7 @@ def _testFDPassSeparate(self):
     @unittest.skipIf(is_apple, "skipping, see issue #12958")
     @unittest.skipIf(SOLARIS, "skipping, see gh-91214")
     @unittest.skipIf(AIX, "skipping, see issue #22397")
+    @unittest.skipIf(BSD_COMBINES_SCM_RIGHTS, "skipping, see gh-125860")
     @requireAttrs(socket, "CMSG_SPACE")
     def testFDPassSeparateMinSpace(self):
         # Pass two FDs in two separate arrays, receiving them into the
@@ -4219,6 +4226,7 @@ def testFDPassSeparateMinSpace(self):
     @unittest.skipIf(is_apple, "skipping, see issue #12958")
     @unittest.skipIf(SOLARIS, "skipping, see gh-91214")
     @unittest.skipIf(AIX, "skipping, see issue #22397")
+    @unittest.skipIf(BSD_COMBINES_SCM_RIGHTS, "skipping, see gh-125860")
     def _testFDPassSeparateMinSpace(self):
         fd0, fd1 = self.newFDs(2)
         self.assertEqual(