From eb7d4b2178e095fd55c8604dd6e123555b1b1ca9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jelmer=20Vernoo=C4=B3?= <jelmer@jelmer.uk>
Date: Sun, 6 Jan 2019 23:49:16 +0000
Subject: [PATCH] Bazaar: Export directly from the remote branch.

This significantly improves performance, since it allows the remote
server to directly stream a tarball that just contains the requested
revision rather than the full repository contents.
---
 .travis.yml                         |  4 ++++
 news/5443.feature                   |  1 +
 src/pip/_internal/vcs/bazaar.py     | 13 +++++--------
 tests/functional/test_vcs_bazaar.py | 25 +++++++++++++++++++++++++
 4 files changed, 35 insertions(+), 8 deletions(-)
 create mode 100644 news/5443.feature
 create mode 100644 tests/functional/test_vcs_bazaar.py

diff --git a/.travis.yml b/.travis.yml
index 430dd76db..bb64a6123 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,10 @@ language: python
 cache: pip
 dist: xenial
 python: 3.6
+addons:
+  apt:
+    packages:
+    - bzr
 
 stages:
 - primary
diff --git a/news/5443.feature b/news/5443.feature
new file mode 100644
index 000000000..4e1215bef
--- /dev/null
+++ b/news/5443.feature
@@ -0,0 +1 @@
+Avoid creating an unnecessary local clone of a Bazaar branch when exporting.
diff --git a/src/pip/_internal/vcs/bazaar.py b/src/pip/_internal/vcs/bazaar.py
index 4c6ac79d1..93456d5cd 100644
--- a/src/pip/_internal/vcs/bazaar.py
+++ b/src/pip/_internal/vcs/bazaar.py
@@ -9,7 +9,6 @@ from pip._internal.download import path_to_url
 from pip._internal.utils.misc import (
     display_path, make_vcs_requirement_url, rmtree,
 )
-from pip._internal.utils.temp_dir import TempDirectory
 from pip._internal.vcs import VersionControl, vcs
 
 logger = logging.getLogger(__name__)
@@ -42,13 +41,11 @@ class Bazaar(VersionControl):
         if os.path.exists(location):
             rmtree(location)
 
-        with TempDirectory(kind="export") as temp_dir:
-            self.unpack(temp_dir.path)
-
-            self.run_command(
-                ['export', location],
-                cwd=temp_dir.path, show_stdout=False,
-            )
+        url, rev_options = self.get_url_rev_options(self.url)
+        self.run_command(
+            ['export', location, url] + rev_options.to_args(),
+            show_stdout=False,
+        )
 
     def fetch_new(self, dest, url, rev_options):
         rev_display = rev_options.to_display()
diff --git a/tests/functional/test_vcs_bazaar.py b/tests/functional/test_vcs_bazaar.py
new file mode 100644
index 000000000..8852cdc63
--- /dev/null
+++ b/tests/functional/test_vcs_bazaar.py
@@ -0,0 +1,25 @@
+"""
+Contains functional tests of the Bazaar class.
+"""
+
+import os
+
+from pip._internal.vcs.bazaar import Bazaar
+from tests.lib import _test_path_to_file_url, _vcs_add, create_file, need_bzr
+
+
+@need_bzr
+def test_export(script, tmpdir):
+    """Test that a Bazaar branch can be exported."""
+    branch_path = tmpdir / 'test-branch'
+    branch_path.mkdir()
+
+    create_file(branch_path / 'test_file', 'something')
+
+    _vcs_add(script, str(branch_path), vcs='bazaar')
+
+    bzr = Bazaar('bzr+' + _test_path_to_file_url(branch_path))
+    export_dir = str(tmpdir / 'export')
+    bzr.export(export_dir)
+
+    assert os.listdir(export_dir) == ['test_file']