From 1c5a65723e623be32e246f58b8797a263f616295 Mon Sep 17 00:00:00 2001
From: Anthony Sottile <asottile@umich.edu>
Date: Sun, 18 Oct 2020 14:14:18 -0700
Subject: bpo-40492: Fix --outfile with relative path when the program changes
 it working dir (GH-19910)

(cherry picked from commit 3c0ac18504cfeed822439024339d5717f42bdd66)
---
 Lib/cProfile.py                                          |  5 +++++
 Lib/profile.py                                           |  5 +++++
 Lib/test/test_profile.py                                 | 16 +++++++++++++++-
 .../Library/2020-05-04-12-16-00.bpo-40492.ONk9Na.rst     |  3 +++
 4 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2020-05-04-12-16-00.bpo-40492.ONk9Na.rst

diff --git a/Lib/cProfile.py b/Lib/cProfile.py
index 369d02e..47aacf9 100755
--- a/Lib/cProfile.py
+++ b/Lib/cProfile.py
@@ -168,6 +168,11 @@ def main():
     (options, args) = parser.parse_args()
     sys.argv[:] = args
 
+    # The script that we're profiling may chdir, so capture the absolute path
+    # to the output file at startup.
+    if options.outfile is not None:
+        options.outfile = os.path.abspath(options.outfile)
+
     if len(args) > 0:
         if options.module:
             code = "run_module(modname, run_name='__main__')"
diff --git a/Lib/profile.py b/Lib/profile.py
index 1346297..9df4435 100755
--- a/Lib/profile.py
+++ b/Lib/profile.py
@@ -587,6 +587,11 @@ def main():
     (options, args) = parser.parse_args()
     sys.argv[:] = args
 
+    # The script that we're profiling may chdir, so capture the absolute path
+    # to the output file at startup.
+    if options.outfile is not None:
+        options.outfile = os.path.abspath(options.outfile)
+
     if len(args) > 0:
         if options.module:
             import runpy
diff --git a/Lib/test/test_profile.py b/Lib/test/test_profile.py
index 01a8a6e..2336498 100644
--- a/Lib/test/test_profile.py
+++ b/Lib/test/test_profile.py
@@ -6,7 +6,7 @@ import unittest
 import os
 from difflib import unified_diff
 from io import StringIO
-from test.support import TESTFN, run_unittest, unlink
+from test.support import TESTFN, run_unittest, unlink, temp_dir, change_cwd
 from contextlib import contextmanager
 
 import profile
@@ -111,6 +111,20 @@ class ProfileTest(unittest.TestCase):
         assert_python_ok('-m', self.profilermodule.__name__,
                          '-m', 'timeit', '-n', '1')
 
+    def test_output_file_when_changing_directory(self):
+        with temp_dir() as tmpdir, change_cwd(tmpdir):
+            os.mkdir('dest')
+            with open('demo.py', 'w') as f:
+                f.write('import os; os.chdir("dest")')
+
+            assert_python_ok(
+                '-m', self.profilermodule.__name__,
+                '-o', 'out.pstats',
+                'demo.py',
+            )
+
+            self.assertTrue(os.path.exists('out.pstats'))
+
 
 def regenerate_expected_output(filename, cls):
     filename = filename.rstrip('co')
diff --git a/Misc/NEWS.d/next/Library/2020-05-04-12-16-00.bpo-40492.ONk9Na.rst b/Misc/NEWS.d/next/Library/2020-05-04-12-16-00.bpo-40492.ONk9Na.rst
new file mode 100644
index 0000000..86bc08c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-05-04-12-16-00.bpo-40492.ONk9Na.rst
@@ -0,0 +1,3 @@
+Fix ``--outfile`` for :mod:`cProfile` / :mod:`profile` not writing the output
+file in the original directory when the program being profiled changes the
+working directory.  PR by Anthony Sottile.
-- 
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