fix issue240: allow to specify empty argument list without it being

rewritten to ".".  Thanks Daniel Hahler.

3 files changed, 16 insertions, 3 deletions

diff --git a/CHANGELOG b/CHANGELOG
index b3e9f7e..29008b0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -29,6 +29,9 @@
 
 - tox has now somewhat pep8 clean code, thanks to Volodymyr Vitvitski.
 
+- fix issue240: allow to specify empty argument list without it being
+  rewritten to ".".  Thanks Daniel Hahler.
+
 
 1.9.2
 -----------
diff --git a/tests/test_config.py b/tests/test_config.py
index 0f271d7..79c98bd 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -863,6 +863,15 @@ class TestConfigTestEnv:
         assert argv[0] == ["cmd1", "[hello]", "world"]
         assert argv[1] == ["cmd1", "brave", "new", "world"]
 
+    def test_substitution_noargs_issue240(self, newconfig):
+        inisource = """
+            [testenv]
+            commands = echo {posargs:foo}
+        """
+        conf = newconfig([""], inisource).envconfigs['python']
+        argv = conf.commands
+        assert argv[0] == ["echo"]
+
     def test_posargs_backslashed_or_quoted(self, tmpdir, newconfig):
         inisource = """
             [testenv:py24]
diff --git a/tox/_config.py b/tox/_config.py
index afd2c55..4468d86 100644
--- a/tox/_config.py
+++ b/tox/_config.py
@@ -373,9 +373,10 @@ class parseini:
             if vc.args_are_paths:
                 args = []
                 for arg in config.option.args:
-                    origpath = config.invocationcwd.join(arg, abs=True)
-                    if origpath.check():
-                        arg = vc.changedir.bestrelpath(origpath)
+                    if arg:
+                        origpath = config.invocationcwd.join(arg, abs=True)
+                        if origpath.check():
+                            arg = vc.changedir.bestrelpath(origpath)
                     args.append(arg)
             reader.addsubstitutions(args)
         setenv = {}