From 5a4d87dc7cf04bd567d88f0ff85f92f3a39d2d36 Mon Sep 17 00:00:00 2001
From: Easley <nevermore.wd@me.com>
Date: Wed, 13 May 2026 18:15:09 +0200
Subject: [PATCH] await output and error tasks concurrently via Task.WhenAll

---
 .../src/System/Diagnostics/Process.Multiplexing.cs             | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Multiplexing.cs b/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Multiplexing.cs
index 6223af6cae0cb6..77ad161ac1496a 100644
--- a/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Multiplexing.cs
+++ b/src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Multiplexing.cs
@@ -562,8 +562,7 @@ public async IAsyncEnumerable<ProcessOutputLine> ReadAllLinesAsync([EnumeratorCa
 
                 // Ensure both tasks complete before disposing the CancellationTokenSource.
                 // The tasks handle all exceptions internally, so they always run to completion.
-                await outputTask.ConfigureAwait(false);
-                await errorTask.ConfigureAwait(false);
+                await Task.WhenAll(outputTask, errorTask).ConfigureAwait(false);
 
                 linkedCts.Dispose();
             }