contrib: upnp: do not try to detach detached thread

This is a cherry-pick of a patch in the 1.6.x branch that has not been released
yet.

(cherry picked from commit 4a44a134ac)

Signed-off-by: Steve Lhomme <robux4@ycbcr.xyz>

contrib/src/upnp/0001-Do-not-try-to-detach-detached-thread-the-result-is-u.patch

@@ -0,0 +1,30 @@
+From de5cd603acd5c81ec947fd9664817231a3d2c418 Mon Sep 17 00:00:00 2001
+From: Jean-Francois Dockes <jf@dockes.org>
+Date: Sun, 27 Jan 2019 10:44:17 +0100
+Subject: [PATCH] Do not try to detach detached thread, the result is
+ undefined. Fixes issue #102
+
+(cherry picked from commit 386b7ed79146ecf7a3bba49f48cb8f41a9b49170)
+---
+ threadutil/src/ThreadPool.c | 5 -----
+ 1 file changed, 5 deletions(-)
+
+diff --git a/threadutil/src/ThreadPool.c b/threadutil/src/ThreadPool.c
+index fcf71087..8c6cd092 100644
+--- a/threadutil/src/ThreadPool.c
++++ b/threadutil/src/ThreadPool.c
+@@ -651,11 +651,6 @@ static int CreateWorker(
+ 	rc = ithread_create(&temp, &attr, WorkerThread, tp);
+ 	ithread_attr_destroy(&attr);
+ 	if (rc == 0) {
+-		rc = ithread_detach(temp);
+-		/* ithread_detach will return EINVAL if thread has been
+-		 successfully detached by ithread_create */
+-		if (rc == EINVAL)
+-			rc = 0;
+ 		tp->pendingWorkerThreadStart = 1;
+ 		/* wait until the new worker thread starts */
+ 		while (tp->pendingWorkerThreadStart) {
+-- 
+2.27.0.windows.1
+

contrib/src/upnp/rules.mak

@@ -28,6 +28,7 @@ endif
 
 upnp: libupnp-$(UPNP_VERSION).tar.bz2 .sum-upnp
 	$(UNPACK)
+	$(APPLY) $(SRC)/upnp/0001-Do-not-try-to-detach-detached-thread-the-result-is-u.patch
 ifdef HAVE_WIN32
 	$(APPLY) $(SRC)/upnp/libupnp-win32.patch
 	$(APPLY) $(SRC)/upnp/libupnp-win64.patch