Fixes piskvorky#2069: wrong malletmodel2ldamodel

`malletmodel2ldamodel` sets up expElogbeta attribute
but LdaModel.show_topics uses inner not dirichleted state instead.
And moreover LdaState and LdaModel were not synced.

gensim/models/wrappers/ldamallet.py

@@ -588,9 +588,11 @@ def malletmodel2ldamodel(mallet_model, gamma_threshold=0.001, iterations=50):
     """
     model_gensim = LdaModel(
         id2word=mallet_model.id2word, num_topics=mallet_model.num_topics,
-        alpha=mallet_model.alpha, iterations=iterations,
+        alpha=mallet_model.alpha, eta=0,
+        iterations=iterations,
         gamma_threshold=gamma_threshold,
         dtype=numpy.float64  # don't loose precision when converting from MALLET
     )
-    model_gensim.expElogbeta[:] = mallet_model.wordtopics
+    model_gensim.state.sstats[...] = mallet_model.wordtopics
+    model_gensim.sync_state()
     return model_gensim

gensim/test/test_ldamallet_wrapper.py

@@ -90,6 +90,10 @@ def testMallet2Model(self):
 
         tm1 = ldamallet.LdaMallet(self.mallet_path, corpus=corpus, num_topics=2, id2word=dictionary)
         tm2 = ldamallet.malletmodel2ldamodel(tm1)
+
+        # set num_topics=-1 to exclude random influence
+        self.assertEqual(tm1.show_topics(-1, 10), tm2.show_topics(-1, 10))
+
         for document in corpus:
             element1_1, element1_2 = tm1[document][0]
             element2_1, element2_2 = tm2[document][0]
@@ -101,7 +105,7 @@ def testMallet2Model(self):
             self.assertAlmostEqual(element1_2, element2_2, 1)
             logging.debug('%d %d', element1_1, element2_1)
             logging.debug('%d %d', element1_2, element2_2)
-            logging.debug('%d %d', tm1[document][1], tm2[document][1])
+            logging.debug('%s %s', tm1[document][1], tm2[document][1])
 
     def testPersistence(self):
         if not self.mallet_path: