Merge

diff --cc Lib/unittest/main.py
index a25a2f8e92f19024664afb17866c6c6a98358409,d09bccdf2c22c53d14a5485ab13ae91c3a7dabdb..061916c052b7f039f605f3fb312aaaf3169a750a
--- 1/Lib/unittest/main.py
--- 2/Lib/unittest/main.py
+++ b/Lib/unittest/main.py
@@@ -174,7 -197,13 +174,8 @@@ class TestProgram(object)
              self.test = self.testLoader.loadTestsFromNames(self.testNames,
                                                             self.module)
  
 -    def _do_discovery(self, argv, Loader=None):
 -        if Loader is None:
 -            Loader = self.testLoader
 -
 -        # handle command line args for test discovery
 -        self.progName = '%s discover' % self.progName
 +    def _getOptParser(self):
+         import optparse
          parser = optparse.OptionParser()
          parser.prog = self.progName
          parser.add_option('-v', '--verbose', dest='verbose', default=False,
@@@ -219,12 -227,6 +220,15 @@@
          parser.add_option('-t', '--top-level-directory', dest='top', default=None,
                            help='Top level directory of project (defaults to start directory)')
  
-     def _do_discovery(self, argv, Loader=loader.TestLoader):
++    def _do_discovery(self, argv, Loader=None):
++        if Loader is None:
++            Loader = self.testLoader
++
 +        # handle command line args for test discovery
 +        self.progName = '%s discover' % self.progName
 +        parser = self._getOptParser()
 +        self._addDiscoveryOptions(parser)
 +
          options, args = parser.parse_args(argv)
          if len(args) > 3:
              self.usageExit()

diff --cc Misc/NEWS
index a56a1b3c5366b4db87d2ad32687391eb21221880,d6ac0e7d610d3b5aef071fd5fb29bca72315537e..0534ef1b075d9207995714c925798863d846c1e4
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -175,8 -221,8 +175,10 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #17502: unittest discovery should use self.testLoader.
+ 
 +- Issue #4591: Uid and gid values larger than 2**31 are supported now.
 +
  - Issue #17141: random.vonmisesvariate() no more hangs for large kappas.
  
  - Issue #17149: Fix random.vonmisesvariate to always return results in