From 5300b0b490b8db48fac30b5e32164be93dc574b7 Mon Sep 17 00:00:00 2001
From: Jakub Roztocil <jakub@roztocil.co>
Date: Thu, 17 Mar 2016 15:58:01 +0800
Subject: [PATCH] Fixed #451 - OSError: [Errno 36] File name too long

---
 CHANGELOG.rst           |  1 +
 httpie/downloads.py     | 36 ++++++++++++++++++++++++++++++++++--
 tests/test_downloads.py | 34 ++++++++++++++++++++++++++++++----
 3 files changed, 65 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ce50d302..23bda11a 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -27,6 +27,7 @@ This project adheres to `Semantic Versioning <http://semver.org/>`_.
   of light and dark terminals
 * Improved ``--debug`` output
 * Fixed ``--session`` when used with ``--download``
+* Fixed ``--download`` to trim too long filenames before saving the file
 * Fixed handling of ``Content-Type`` with multiple ``+subtype`` parts
 
 
diff --git a/httpie/downloads.py b/httpie/downloads.py
index b49e3352..972151e1 100644
--- a/httpie/downloads.py
+++ b/httpie/downloads.py
@@ -7,6 +7,7 @@ from __future__ import division
 import os
 import re
 import sys
+import errno
 import mimetypes
 import threading
 from time import sleep, time
@@ -135,12 +136,43 @@ def filename_from_url(url, content_type):
     return fn
 
 
+def trim_filename(filename, max_len):
+    if len(filename) > max_len:
+        trim_by = len(filename) - max_len
+        name, ext = os.path.splitext(filename)
+        if trim_by >= len(name):
+            filename = filename[:-trim_by]
+        else:
+            filename = name[:-trim_by] + ext
+    return filename
+
+
+def get_filename_max_length(directory):
+    try:
+        max_len = os.pathconf(directory, 'PC_NAME_MAX')
+    except OSError as e:
+        if e.errno == errno.EINVAL:
+            max_len = 255
+        else:
+            raise
+    return max_len
+
+
+def trim_filename_if_needed(filename, directory='.', extra=0):
+    max_len = get_filename_max_length(directory) - extra
+    if len(filename) > max_len:
+        filename = trim_filename(filename, max_len)
+    return filename
+
+
 def get_unique_filename(filename, exists=os.path.exists):
     attempt = 0
     while True:
         suffix = '-' + str(attempt) if attempt > 0 else ''
-        if not exists(filename + suffix):
-            return filename + suffix
+        try_filename = trim_filename_if_needed(filename, extra=len(suffix))
+        try_filename += suffix
+        if not exists(try_filename):
+            return try_filename
         attempt += 1
 
 
diff --git a/tests/test_downloads.py b/tests/test_downloads.py
index 2d973c33..e09bdde3 100644
--- a/tests/test_downloads.py
+++ b/tests/test_downloads.py
@@ -2,6 +2,7 @@ import os
 import time
 
 import pytest
+import mock
 from requests.structures import CaseInsensitiveDict
 
 from httpie.compat import urlopen
@@ -74,7 +75,31 @@ class TestDownloadUtils:
             content_type='x-foo/bar'
         )
 
-    def test_unique_filename(self):
+    @pytest.mark.parametrize(
+        'orig_name, unique_on_attempt, expected',
+        [
+            # Simple
+            ('foo.bar', 0, 'foo.bar'),
+            ('foo.bar', 1, 'foo.bar-1'),
+            ('foo.bar', 10, 'foo.bar-10'),
+            # Trim
+            ('A' * 20, 0, 'A' * 10),
+            ('A' * 20, 1, 'A' * 8 + '-1'),
+            ('A' * 20, 10, 'A' * 7 + '-10'),
+            # Trim before ext
+            ('A' * 20 + '.txt', 0, 'A' * 6 + '.txt'),
+            ('A' * 20 + '.txt', 1, 'A' * 4 + '.txt-1'),
+            # Trim at the end
+            ('foo.' + 'A' * 20, 0, 'foo.' + 'A' * 6),
+            ('foo.' + 'A' * 20, 1, 'foo.' + 'A' * 4 + '-1'),
+            ('foo.' + 'A' * 20, 10, 'foo.' + 'A' * 3 + '-10'),
+        ]
+    )
+    @mock.patch('httpie.downloads.get_filename_max_length')
+    def test_unique_filename(self, get_filename_max_length,
+                             orig_name, unique_on_attempt,
+                             expected):
+
         def attempts(unique_on_attempt=0):
             # noinspection PyUnresolvedReferences,PyUnusedLocal
             def exists(filename):
@@ -86,9 +111,10 @@ class TestDownloadUtils:
             exists.attempt = 0
             return exists
 
-        assert 'foo.bar' == get_unique_filename('foo.bar', attempts(0))
-        assert 'foo.bar-1' == get_unique_filename('foo.bar', attempts(1))
-        assert 'foo.bar-10' == get_unique_filename('foo.bar', attempts(10))
+        get_filename_max_length.return_value = 10
+
+        actual = get_unique_filename(orig_name, attempts(unique_on_attempt))
+        assert expected == actual
 
 
 class TestDownloads: