From 4c6c5a2eedba9b1a9ec64be87284ec18d35cb7bf Mon Sep 17 00:00:00 2001
From: samyak jain <mnsn1970@gmail.com>
Date: Fri, 16 Feb 2018 15:14:08 +0530
Subject: [PATCH] Fixes #1869 , Mmcorpus file-like object behaviour fixed

---
 gensim/matutils.py          | 51 ++++++++++++++++++++++++-------------
 gensim/test/test_corpora.py |  8 ++++++
 2 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/gensim/matutils.py b/gensim/matutils.py
index 3b4dce9c4a..bd5c8a34d5 100644
--- a/gensim/matutils.py
+++ b/gensim/matutils.py
@@ -1272,25 +1272,40 @@ def __init__(self, input, transposed=True):
         """
         logger.info("initializing corpus reader from %s", input)
         self.input, self.transposed = input, transposed
-        with utils.file_or_filename(self.input) as lines:
+
+        # 'with' statement behaviour without closing the file object
+        mgr = (utils.file_or_filename(self.input))
+        exit = type(mgr).__exit__
+        value = type(mgr).__enter__(mgr)
+        exc = True
+        try:
             try:
-                header = utils.to_unicode(next(lines)).strip()
-                if not header.lower().startswith('%%matrixmarket matrix coordinate real general'):
-                    raise ValueError(
-                        "File %s not in Matrix Market format with coordinate real general; instead found: \n%s" %
-                        (self.input, header)
-                    )
-            except StopIteration:
-                pass
-
-            self.num_docs = self.num_terms = self.num_nnz = 0
-            for lineno, line in enumerate(lines):
-                line = utils.to_unicode(line)
-                if not line.startswith('%'):
-                    self.num_docs, self.num_terms, self.num_nnz = (int(x) for x in line.split())
-                    if not self.transposed:
-                        self.num_docs, self.num_terms = self.num_terms, self.num_docs
-                    break
+                lines = value
+                try:
+                    header = utils.to_unicode(next(lines)).strip()
+                    if not header.lower().startswith('%%matrixmarket matrix coordinate real general'):
+                        raise ValueError(
+                            "File %s not in Matrix Market format with coordinate real general; instead found: \n%s" %
+                            (self.input, header)
+                        )
+                except StopIteration:
+                    pass
+
+                self.num_docs = self.num_terms = self.num_nnz = 0
+                for lineno, line in enumerate(lines):
+                    line = utils.to_unicode(line)
+                    if not line.startswith('%'):
+                        self.num_docs, self.num_terms, self.num_nnz = (int(x) for x in line.split())
+                        if not self.transposed:
+                            self.num_docs, self.num_terms = self.num_terms, self.num_docs
+                        break
+            except:
+                exc = False
+                if not exit(mgr, *sys.exc_info()):
+                    raise
+        finally:
+            if isinstance(self.input, string_types):
+                exit(mgr, None, None, None)
 
         logger.info(
             "accepted corpus with %i documents, %i features, %i non-zero entries",
diff --git a/gensim/test/test_corpora.py b/gensim/test/test_corpora.py
index f330dbd271..79a7b2c93f 100644
--- a/gensim/test/test_corpora.py
+++ b/gensim/test/test_corpora.py
@@ -224,6 +224,14 @@ def setUp(self):
     def test_serialize_compressed(self):
         # MmCorpus needs file write with seek => doesn't support compressed output (only input)
         pass
+    
+    def test_closed_file_object(self):
+        file_obj = open(datapath('testcorpus.mm'))
+        f = file_obj.closed
+        corpus = mmcorpus.MmCorpus(file_obj)
+        s = file_obj.closed
+        self.assertEqual(f, 0)
+        self.assertEqual(s, 0)
 
     def test_load(self):
         self.assertEqual(self.corpus.num_docs, 9)