1 files changed, 32 insertions, 1 deletions
diff --git a/otherlibs/win32unix/createprocess.c b/otherlibs/win32unix/createprocess.c
index 006dec7b7..d0e2abba9 100644
--- a/otherlibs/win32unix/createprocess.c
+++ b/otherlibs/win32unix/createprocess.c
@@ -19,12 +19,15 @@
 /* From the Caml runtime */
 extern char * searchpath(char * name);
 
+static int win_has_console(void);
+
 value win_create_process_native(value cmd, value cmdline, value env,
                                 value fd1, value fd2, value fd3)
 {
   PROCESS_INFORMATION pi;
   STARTUPINFO si;
   char * exefile, * envp;
+  int flags;
 
   exefile = searchpath(String_val(cmd));
   if (exefile == NULL) exefile = String_val(cmd);
@@ -33,16 +36,30 @@ value win_create_process_native(value cmd, value cmdline, value env,
   } else {
     envp = NULL;
   }
+  /* Prepare stdin/stdout/stderr redirection */
   GetStartupInfo(&si);
   si.dwFlags |= STARTF_USESTDHANDLES;
   si.hStdInput = Handle_val(fd1);
   si.hStdOutput = Handle_val(fd2);
   si.hStdError = Handle_val(fd3);
+  /* If we do not have a console window, then we must run
+     console mode applications as detached processes.
+     Otherwise, a new console is created and the redirections
+     are ignored.  If we're running a GUI application, the
+     detached / non-detached flag doesn't matter. */
+  if (win_has_console())
+    flags = 0;
+  else
+    flags = DETACHED_PROCESS;
+  /* Create the process */
   if (! CreateProcess(exefile, String_val(cmdline), NULL, NULL,
-                      TRUE, 0, envp, NULL, &si, &pi)) {
+                      TRUE, flags, envp, NULL, &si, &pi)) {
     _dosmaperr(GetLastError());
     uerror("create_process", cmd);
   }
+  CloseHandle(pi.hThread);
+  /* Return the process handle as pseudo-PID
+     (this is consistent with the wait() emulation in the MSVC C library */
   return Val_int(pi.hProcess);
 }
 
@@ -51,3 +68,17 @@ value win_create_process(value * argv, int argn) /* ML */
   return win_create_process_native(argv[0], argv[1], argv[2],
                                    argv[3], argv[4], argv[5]);
 }
+
+static int win_has_console(void)
+{
+  HANDLE h;
+
+  h = CreateFile("CONOUT$", GENERIC_WRITE, FILE_SHARE_WRITE, NULL,
+                 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+  if (h == INVALID_HANDLE_VALUE) {
+    return 0;
+  } else {
+    CloseHandle(h);
+    return 1;
+  }
+}