From 7a6dfaaded267553995f1310ef31fc660094e0ec Mon Sep 17 00:00:00 2001 From: Prithviraj Chaudhuri Date: Sun, 28 Dec 2025 11:57:44 -0500 Subject: [PATCH] gh-142195: Fixed Popen.communicate indefinite loops (GH-143203) Changed condition to evaluate if timeout is less than or equals to 0. This is needed for simulated time environments such as Shadow where the time will match exactly on the boundary. --------- (cherry picked from commit fa9a4254e81c0abcc3345021c45aaf5f788f9ea9) Co-authored-by: Prithviraj Chaudhuri Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com> --- Lib/subprocess.py | 2 +- .../next/Library/2025-12-27-00-14-56.gh-issue-142195.UgBEo5.rst | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2025-12-27-00-14-56.gh-issue-142195.UgBEo5.rst diff --git a/Lib/subprocess.py b/Lib/subprocess.py index 6911cd8e85973d..578d7b95d05d7b 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -2141,7 +2141,7 @@ def _communicate(self, input, endtime, orig_timeout): while selector.get_map(): timeout = self._remaining_time(endtime) - if timeout is not None and timeout < 0: + if timeout is not None and timeout <= 0: self._check_timeout(endtime, orig_timeout, stdout, stderr, skip_check_and_raise=True) diff --git a/Misc/NEWS.d/next/Library/2025-12-27-00-14-56.gh-issue-142195.UgBEo5.rst b/Misc/NEWS.d/next/Library/2025-12-27-00-14-56.gh-issue-142195.UgBEo5.rst new file mode 100644 index 00000000000000..b2b1ffe7225bd7 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2025-12-27-00-14-56.gh-issue-142195.UgBEo5.rst @@ -0,0 +1 @@ +Updated timeout evaluation logic in :mod:`subprocess` to be compatible with deterministic environments like Shadow where time moves exactly as requested.