From 7d0cdfc79dfa9c2c631cc41e3ccca62e19d8041e Mon Sep 17 00:00:00 2001
From: Mark Leyva <maleyva1@users.noreply.github.com>
Date: Mon, 1 Jul 2024 02:42:11 -0700
Subject: [PATCH] fixes #5091; Ensure we don't wait on an exited process on
 Linux (#23743)

Fixes #5091.

Ensure we don't wait on an exited process on Linux

(cherry picked from commit 288d5c4ac32c27704258a15d365a56dadf38b0e9)
---
 lib/pure/osproc.nim           |  2 ++
 tests/osproc/twaitforexit.nim | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 tests/osproc/twaitforexit.nim

diff --git a/lib/pure/osproc.nim b/lib/pure/osproc.nim
index e30f1da737..503d68d06a 100644
--- a/lib/pure/osproc.nim
+++ b/lib/pure/osproc.nim
@@ -1416,6 +1416,8 @@ elif not defined(useNimRtl):
           tmspec.tv_nsec = (timeout * 1_000_000)
 
         try:
+          if not running(p):
+            return exitStatusLikeShell(p.exitStatus)
           if clock_gettime(CLOCK_REALTIME, stspec) == -1:
             raiseOSError(osLastError())
           while true:
diff --git a/tests/osproc/twaitforexit.nim b/tests/osproc/twaitforexit.nim
new file mode 100644
index 0000000000..5db8d25666
--- /dev/null
+++ b/tests/osproc/twaitforexit.nim
@@ -0,0 +1,18 @@
+import std/[osproc, os, times]
+
+block: # bug #5091
+    when defined(linux):
+        const filename = "false"
+        var p = startProcess(filename, options = {poStdErrToStdOut, poUsePath})
+        os.sleep(1000) # make sure process has exited already
+
+        let atStart = getTime()
+        const msWait = 2000
+
+        try:
+            discard waitForExit(p, msWait)
+        except OSError:
+            discard
+
+        # check that we don't have to wait msWait milliseconds
+        doAssert(getTime() <  atStart + milliseconds(msWait))
\ No newline at end of file