Port over changes from #1389

spacy/lemmatizer.py

@@ -94,15 +94,16 @@ def lemmatize(string, index, exceptions, rules):
     #    forms.append(string)
     forms.extend(exceptions.get(string, []))
     oov_forms = []
-    for old, new in rules:
-        if string.endswith(old):
-            form = string[:len(string) - len(old)] + new
-            if not form:
-                pass
-            elif form in index or not form.isalpha():
-                forms.append(form)
-            else:
-                oov_forms.append(form)
+    if not forms:
+        for old, new in rules:
+            if string.endswith(old):
+                form = string[:len(string) - len(old)] + new
+                if not form:
+                    pass
+                elif form in index or not form.isalpha():
+                    forms.append(form)
+                else:
+                    oov_forms.append(form)
     if not forms:
         forms.extend(oov_forms)
     if not forms:

spacy/tests/regression/test_issue1387.py

@@ -0,0 +1,22 @@
+# coding: utf-8
+from __future__ import unicode_literals
+
+from ...symbols import POS, VERB, VerbForm_part
+from ...vocab import Vocab
+from ...lemmatizer import Lemmatizer
+from ..util import get_doc
+
+import pytest
+
+
+def test_issue1387():
+    tag_map = {'VBG': {POS: VERB, VerbForm_part: True}}
+    index = {"verb": ("cope","cop")}
+    exc = {"verb": {"coping": ("cope",)}}
+    rules = {"verb": [["ing", ""]]}
+    lemmatizer = Lemmatizer(index, exc, rules)
+    vocab = Vocab(lemmatizer=lemmatizer, tag_map=tag_map)
+    doc = get_doc(vocab, ["coping"])
+    doc[0].tag_ = 'VBG'
+    assert doc[0].text == "coping"
+    assert doc[0].lemma_ == "cope"