Revert detached check

Author: kleisauke

system/lib/libc/musl/src/thread/pthread_join.c

@@ -10,10 +10,14 @@ weak_alias(dummy1, __tl_sync);
 static int __pthread_timedjoin_np(pthread_t t, void **res, const struct timespec *at)
 {
 #ifdef __EMSCRIPTEN__
-	// XXX Emscripten: Add check for invalid (already joined) thread.
+	// Attempt to join a thread which does not point to a valid thread, or
+	// does not exist anymore.
 	if (!_emscripten_thread_is_valid(t)) return ESRCH;
-	// Thread is attempting to join to itself.
-	if (__pthread_self() == t) return EDEADLK;
+	// Thread is attempting to join to itself.  Already detached threads are
+	// handled below by returning EINVAL instead.
+	// TODO: The detached check here is just to satisfy the
+	// `other.test_{proxy,main}_pthread_join_detach` tests.
+	if (t->detach_state != DT_DETACHED && __pthread_self() == t) return EDEADLK;
 #endif
 	int state, cs, r = 0;
 	__pthread_testcancel();

test/other/test_pthread_self_join_detach.c

@@ -21,11 +21,17 @@ int main() {
   pthread_t self = pthread_self();
 
   /*
-   * Attempts to join the current thread will generate EDEADLK.
+   * Attempts to join the current thread will either generate
+   * EDEADLK or EINVAL depending on whether it has already been
+   * detached
    */
   int ret = pthread_join(self, NULL);
   printf("pthread_join -> %s\n", strerror(ret));
-  assert(ret == EDEADLK);
+  if (is_detached) {
+    assert(ret == EINVAL);
+  } else {
+    assert(ret == EDEADLK);
+  }
 
   /*
    * Attempts to detach the main thread will either succeed
@@ -39,6 +45,10 @@ int main() {
     assert(ret == 0);
   }
 
+  ret = pthread_join(self, NULL);
+  printf("pthread_join -> %s\n", strerror(ret));
+  assert(ret == EINVAL);
+
   puts("passed");
 
   return 0;