Add test for Issue #758

Issue #758 occurs when no actions are available for a single token
doc after merging.

spacy/tests/regression/test_issue758.py

@@ -0,0 +1,17 @@
+from ... import load as load_spacy
+from ...attrs import LEMMA
+from ...matcher import merge_phrase
+
+import pytest
+
+
+
+
+@pytest.mark.models
+def test_issue758():
+    '''Test parser transition bug after label added.'''
+    nlp = load_spacy('en')
+    nlp.matcher.add('splash', 'my_entity', {},
+                    [[{LEMMA: 'splash'}, {LEMMA: 'on'}]],
+                    on_match=merge_phrase)
+    doc = nlp('splash On')