patch 7.4.2301
Problem:    MS-Windows: some files remain after testing.
Solution:   Close the channel output file.  Wait for the file handle to be
            closed before deleting the file.
diff --git a/src/os_win32.c b/src/os_win32.c
index 0de3d64..0607bd2 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -5210,11 +5210,9 @@
     job->jv_job_object = jo;
     job->jv_status = JOB_STARTED;
 
-    if (!use_file_for_in)
-	CloseHandle(ifd[0]);
-    if (!use_file_for_out)
-	CloseHandle(ofd[1]);
-    if (!use_out_for_err && !use_file_for_err)
+    CloseHandle(ifd[0]);
+    CloseHandle(ofd[1]);
+    if (!use_out_for_err && !use_null_for_err)
 	CloseHandle(efd[1]);
 
     job->jv_channel = channel;