From f8e6ad6ac11a5f22c3819cc2064b8b17abf97a9d Mon Sep 17 00:00:00 2001
From: Pieter Marsman <pietermarsman@gmail.com>
Date: Sun, 25 Oct 2020 14:37:12 +0100
Subject: [PATCH] Remove supoprt for non standard output streams that are not
 binary by removing the try-except check that writes a unicode character to
 the stream (#523)

Closes #191

* Remove supoprt for non standard output streams that are not binary by removing the try-except check that writes a unicode character to the stream

* Add docstring

* Fix flake8
---
 CHANGELOG.md            |  1 +
 pdfminer/converter.py   | 35 +++++++++++++++++------------------
 tests/test_converter.py | 26 ++++++++++++++++++++++++--
 3 files changed, 42 insertions(+), 20 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9a02a4..9428db9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## Removed
 - Support for Python 3.4 and 3.5 ([#522](https://github.com/pdfminer/pdfminer.six/pull/522))
 - Unused dependency on `sortedcontainers` package ([#525](https://github.com/pdfminer/pdfminer.six/pull/525))
+- Support for non-standard output streams that are not binary ([#523](https://github.com/pdfminer/pdfminer.six/pull/523))
 
 ## [20201018]
 
diff --git a/pdfminer/converter.py b/pdfminer/converter.py
index dcdb055..0c5742c 100644
--- a/pdfminer/converter.py
+++ b/pdfminer/converter.py
@@ -1,3 +1,4 @@
+import io
 import logging
 import re
 import sys
@@ -167,24 +168,22 @@ class PDFConverter(PDFLayoutAnalyzer):
                                    laparams=laparams)
         self.outfp = outfp
         self.codec = codec
-        if hasattr(self.outfp, 'mode'):
-            if 'b' in self.outfp.mode:
-                self.outfp_binary = True
-            else:
-                self.outfp_binary = False
-        else:
-            import io
-            if isinstance(self.outfp, io.BytesIO):
-                self.outfp_binary = True
-            elif isinstance(self.outfp, io.StringIO):
-                self.outfp_binary = False
-            else:
-                try:
-                    self.outfp.write("é")
-                    self.outfp_binary = False
-                except TypeError:
-                    self.outfp_binary = True
-        return
+        self.outfp_binary = self._is_binary_stream(self.outfp)
+
+    @staticmethod
+    def _is_binary_stream(outfp):
+        """Test if an stream is binary or not"""
+        if 'b' in getattr(outfp, 'mode', ''):
+            return True
+        elif hasattr(outfp, 'mode'):
+            # output stream has a mode, but it does not contain 'b'
+            return False
+        elif isinstance(outfp, io.BytesIO):
+            return True
+        elif isinstance(outfp, io.StringIO):
+            return False
+
+        return True
 
 
 class TextConverter(PDFConverter):
diff --git a/tests/test_converter.py b/tests/test_converter.py
index c36a572..cfd1f2a 100644
--- a/tests/test_converter.py
+++ b/tests/test_converter.py
@@ -1,6 +1,9 @@
-from nose.tools import assert_equal
+import io
+from tempfile import TemporaryFile
 
-from pdfminer.converter import PDFLayoutAnalyzer
+from nose.tools import assert_equal, assert_false, assert_true
+
+from pdfminer.converter import PDFLayoutAnalyzer, PDFConverter
 from pdfminer.layout import LTContainer, LTRect, LTCurve
 from pdfminer.pdfinterp import PDFGraphicState
 
@@ -99,3 +102,22 @@ class TestPaintPath():
         analyzer = PDFLayoutAnalyzer(None)
         analyzer.set_ctm([1, 0, 0, 1, 0, 0])
         return analyzer
+
+
+class TestBinaryDetector():
+    def test_stringio(self):
+        assert_false(PDFConverter._is_binary_stream(io.StringIO()))
+
+    def test_bytesio(self):
+        assert_true(PDFConverter._is_binary_stream(io.BytesIO()))
+
+    def test_tmpfile(self):
+        with TemporaryFile(mode='w') as f:
+            assert_false(PDFConverter._is_binary_stream(f))
+
+    def test_binary_tmpfile(self):
+        with TemporaryFile(mode='wb') as f:
+            assert_true(PDFConverter._is_binary_stream(f))
+
+    def test_non_file_like_object_defaults_to_binary(self):
+        assert_true(PDFConverter._is_binary_stream(object()))