From a5a62154d4f53f42e116cc9bc722302798b1b326 Mon Sep 17 00:00:00 2001
From: Erik Montnemery <erik@montnemery.com>
Date: Mon, 19 Apr 2021 14:45:01 +0200
Subject: [PATCH] Fix deadlock when restarting scripts (#49410)

---
 homeassistant/helpers/script.py | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/homeassistant/helpers/script.py b/homeassistant/helpers/script.py
index 52be3866639..f2afe152569 100644
--- a/homeassistant/helpers/script.py
+++ b/homeassistant/helpers/script.py
@@ -1203,12 +1203,9 @@ class Script:
             self._changed()
             raise
 
-    async def _async_stop(self, update_state, spare=None):
-        aws = [
-            asyncio.create_task(run.async_stop()) for run in self._runs if run != spare
-        ]
-        if not aws:
-            return
+    async def _async_stop(
+        self, aws: list[asyncio.Task], update_state: bool, spare: _ScriptRun | None
+    ) -> None:
         await asyncio.wait(aws)
         if update_state:
             self._changed()
@@ -1217,7 +1214,15 @@ class Script:
         self, update_state: bool = True, spare: _ScriptRun | None = None
     ) -> None:
         """Stop running script."""
-        await asyncio.shield(self._async_stop(update_state, spare))
+        # Collect a a list of script runs to stop. This must be done before calling
+        # asyncio.shield as asyncio.shield yields to the event loop, which would cause
+        # us to wait for script runs added after the call to async_stop.
+        aws = [
+            asyncio.create_task(run.async_stop()) for run in self._runs if run != spare
+        ]
+        if not aws:
+            return
+        await asyncio.shield(self._async_stop(aws, update_state, spare))
 
     async def _async_get_condition(self, config):
         if isinstance(config, template.Template):