server: Fail to set process affinity mask if the process is terminating.

dlls/kernel32/tests/loader.c

@@ -1958,7 +1958,7 @@ todo_wine
     /* Checking process state without waiting for process termination
      * leads to different results due to a race condition.
      */
-    ret = WaitForSingleObject(pi.hProcess, 100);
+    ret = WaitForSingleObject(pi.hProcess, 1000);
     ok(ret == WAIT_OBJECT_0, "WaitForSingleObject failed: %x\n", ret);
 
     memset(&pbi, 0, sizeof(pbi));
@@ -1967,7 +1967,6 @@ todo_wine
     ok(pbi.ExitStatus == 198, "expected 198, got %lu\n", pbi.ExitStatus);
     affinity = 1;
     ret = pNtSetInformationProcess(pi.hProcess, ProcessAffinityMask, &affinity, sizeof(affinity));
-todo_wine
     ok(ret == STATUS_PROCESS_IS_TERMINATING, "expected STATUS_PROCESS_IS_TERMINATING, got %#x\n", ret);
 
     SetLastError(0xdeadbeef);

server/process.c

@@ -1122,6 +1122,12 @@ static void set_process_affinity( struct process *process, affinity_t affinity )
 {
     struct thread *thread;
 
+    if (!process->running_threads)
+    {
+        set_error( STATUS_PROCESS_IS_TERMINATING );
+        return;
+    }
+
     process->affinity = affinity;
 
     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )