FIX: Detecting and apropriately warning about unconnected duplicatlely nodes

nipype/pipeline/engine/tests/test_workflows.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
+# vi: set ft=python sts=4 ts=4 sw=4 et:
+"""Tests for the engine workflows module
+"""
+import pytest
+
+from ... import engine as pe
+from ....interfaces import utility as niu
+
+
+def test_duplicate_node_check():
+
+    wf = pe.Workflow(name="testidentity")
+
+    original_list = [0,1,2,3,4,5,6,7,8,9]
+
+    selector1 = pe.Node(niu.Select(), name="selector1")
+    selector1.inputs.index = original_list[:-1]
+    selector1.inputs.inlist = original_list
+    selector2 = pe.Node(niu.Select(), name="selector2")
+    selector2.inputs.index = original_list[:-2]
+    selector3 = pe.Node(niu.Select(), name="selector3")
+    selector3.inputs.index = original_list[:-3]
+    selector4 = pe.Node(niu.Select(), name="selector3")
+    selector4.inputs.index = original_list[:-4]
+
+    wf_connections = [
+            (selector1, selector2, [("out","inlist")]),
+            (selector2, selector3, [("out","inlist")]),
+            (selector3, selector4, [("out","inlist")]),
+            ]
+
+    with pytest.raises(IOError) as excinfo:
+        wf.connect(wf_connections)
+    assert 'Duplicate node name "selector3" found.' == str(excinfo.value)

nipype/pipeline/engine/workflows.py

@@ -700,8 +700,13 @@ def _check_nodes(self, nodes):
         for node in nodes:
             if node.name in node_names:
                 idx = node_names.index(node.name)
-                if node_lineage[idx] in [node._hierarchy, self.name]:
-                    raise IOError('Duplicate node name %s found.' % node.name)
+                try:
+                    this_node_lineage = node_lineage[idx]
+                except IndexError:
+                    raise IOError('Duplicate node name "%s" found.' % node.name)
+                else:
+                    if this_node_lineage in [node._hierarchy, self.name]:
+                        raise IOError('Duplicate node name "%s" found.' % node.name)
             else:
                 node_names.append(node.name)