Merge pull request #422 from python/master

bpo-43423 Fix IndexError in subprocess _communicate function (pythonGH-24777)
sthagen · Mar 11, 2021 · 6fc610a · 6fc610a
2 parents c24a599 + b4fc44b
commit 6fc610a
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Showing 2 changed files with 4 additions and 4 deletions.
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
@@ -1535,10 +1535,8 @@ def _communicate(self, input, endtime, orig_timeout):
                 self.stderr.close()
 
             # All data exchanged.  Translate lists into strings.
-            if stdout is not None:
-                stdout = stdout[0]
-            if stderr is not None:
-                stderr = stderr[0]
+            stdout = stdout[0] if stdout else None
+            stderr = stderr[0] if stderr else None
 
             return (stdout, stderr)
 

diff --git a/Misc/NEWS.d/next/Library/2021-03-11-15-44-18.bpo-43423.rRomRD.rst b/Misc/NEWS.d/next/Library/2021-03-11-15-44-18.bpo-43423.rRomRD.rst
@@ -0,0 +1,2 @@
+:func:`subprocess.communicate` no longer raises an IndexError when there is an
+empty stdout or stderr IO buffer during a timeout on Windows.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		:func:`subprocess.communicate` no longer raises an IndexError when there is an
		empty stdout or stderr IO buffer during a timeout on Windows.