Zope2.Startup.zopectl: fork before execv when running unit tests

Avoids exiting the zopectl shell, if run from there.

doc/CHANGES.txt

@@ -26,6 +26,9 @@ Zope Changes
 
     Bugs Fixed
 
+      - Zope2.Startup.zopectl: fork before execv when running unit tests
+        (don't exit the shell, if run from there).
+
       - TAL: MassageIDs are now handled the same way as in zope.tal.
 
       - DocumentTemplate: ustr no longer mangles MassageIDs.

lib/python/Zope2/Startup/zopectl.py

@@ -259,7 +259,11 @@ class ZopeCmd(ZDCmd):
         args.insert(0, self.options.python)
 
         print 'Running tests via: %s' % ' '.join(args)
+        pid = os.fork()
+        if pid == 0:  # child
             os.execv(self.options.python, args)
+        else:
+            os.waitpid(pid, 0)
 
     def help_test(self):
         print "test [args]+ -- run unit / functional tests."