From e3e76b426bb17428fe8e3d1bbce4fdaa4d79a9ee Mon Sep 17 00:00:00 2001
From: Tobias Werth <twerth@google.com>
Date: Tue, 24 Jan 2023 16:14:30 +0100
Subject: [PATCH] Handle SIGWINCH in bazel run correctly.

Previously, after two window resize events we would stop waiting for the
child process - this makes sense for other signals but not for SIGWINCH.

Fixes https://github.com/bazelbuild/bazel/issues/17215
---
 tools/test/test-setup.sh | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/tools/test/test-setup.sh b/tools/test/test-setup.sh
index 8529a88535ea61..7ddbd10ad79a58 100755
--- a/tools/test/test-setup.sh
+++ b/tools/test/test-setup.sh
@@ -356,9 +356,25 @@ wait $childPid
 # If interrupted by a signal, use the signal as the exit code. But allow
 # the child to actually finish from the signal we sent _it_ via signal_child.
 # (Waiting on a stopped process is a no-op).
-# Only once - if we receive multiple signals (of any sort), give up.
+# Only once - if we receive multiple signals (except SIGWINCH), give up.
+# SIGWINCH is special since it is sent for every window resize event.
 exitCode=$?
-wait $childPid
+
+# This exitcode indicates that the child received a SIGWINCH (likely forwarded
+# by us).
+sigwinch_exit=$((128+$(kill -l SIGWINCH)))
+only_sigwinch_exit=0
+if [ $exitCode == $sigwinch_exit ]; then
+  only_sigwinch_exit=1
+fi
+while true; do
+  wait $childPid
+  curExitCode=$?
+  if [ $only_sigwinch_exit != 1 ] || [ $curExitCode != $sigwinch_exit ]; then
+    break
+  fi
+done
+
 
 # By this point, we have everything we're willing to wait for. Tidy up our own
 # processes and move on.