fix #1099 / windows: Process.terminate() may raise AccessDenied even …

…if the process already dided

HISTORY.rst

@@ -79,6 +79,8 @@
   on OpenProcess Windows API now check whether the PID is actually running.
 - 1098_: [Windows] Process.wait() may erroneously return sooner, when the PID
   is still alive.
+- 1099_: [Windows] Process.terminate() may raise AccessDenied even if the
+  process already died.
 
 **Porting notes**
 

psutil/_psutil_windows.c

@@ -321,6 +321,7 @@ psutil_pids(PyObject *self, PyObject *args) {
 static PyObject *
 psutil_proc_kill(PyObject *self, PyObject *args) {
     HANDLE hProcess;
+    DWORD err;
     long pid;
 
     if (! PyArg_ParseTuple(args, "l", &pid))
@@ -342,9 +343,16 @@ psutil_proc_kill(PyObject *self, PyObject *args) {
 
     // kill the process
     if (! TerminateProcess(hProcess, 0)) {
-        PyErr_SetFromWindowsErr(0);
+        err = GetLastError();
         CloseHandle(hProcess);
-        return NULL;
+        // See: https://github.com/giampaolo/psutil/issues/1099
+        if (psutil_pid_is_running(pid) == 0) {
+            Py_RETURN_NONE;
+        }
+        else {
+            PyErr_SetFromWindowsErr(err);
+            return NULL;
+        }
     }
 
     CloseHandle(hProcess);