[Emacs-diffs] emacs-26 691790b: Avoid Groff hanging on MS-Windows when invoked by "M-x man"

[Eli Zaretskii]

branch: emacs-26
commit 691790b8ea5192395a2eeac0f89a2f41d74f2ddb
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Avoid Groff hanging on MS-Windows when invoked by "M-x man"
    
    * lisp/man.el (Man-build-man-command): On MS-Windows, redirect
    stdin of 'man' to the null device, to make sure Groff exits
    immediately after formatting the man page.
---
 lisp/man.el | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lisp/man.el b/lisp/man.el
index 409fadb..731d480 100644
--- a/lisp/man.el
+++ b/lisp/man.el
@@ -624,7 +624,13 @@ This is necessary if one wants to dump man.el with Emacs."
                           ;; so we don't need `2>' even with DOS shells
                           ;; which do support stderr redirection.
                           ((not (fboundp 'make-process)) " %s")
-                          ((concat " %s 2>" null-device)))))
+                          ((concat " %s 2>" null-device
+                                   ;; Some MS-Windows ports of Groff
+                                   ;; try to read stdin after exhausting
+                                   ;; the command-line arguments; make
+                                   ;; them exit if/when they do.
+                                   (if (eq system-type 'windows-nt)
+                                       (concat " <" null-device)))))))
        (flist Man-filter-list))
     (while (and flist (car flist))
       (let ((pcom (car (car flist)))