Make stty settings configurable in Tramp's make-process

* lisp/net/tramp-sh.el (tramp-pipe-stty-settings): New defcustom.
(tramp-sh-handle-make-process): Use it.  (Bug#62093)

1 files changed, 24 insertions, 6 deletions

diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 064045584ae..1777e2f1ed8 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -2877,7 +2877,16 @@ the result will be a local, non-Tramp, file name."
                 (tramp-run-real-handler
                  #'expand-file-name (list localname))))))))))
 
-;;; Remote commands:
+;;; Remote processes:
+
+(defcustom tramp-pipe-stty-settings "-icanon min 1 time 0"
+  "How to prevent blocking read in pipeline processes.
+This is used in `make-process' with `connection-type' `pipe'."
+  :group 'tramp
+  :version "29.3"
+  :type '(choice (const :tag "Use size limit" "-icanon min 1 time 0")
+                 (const :tag "Use timeout" "-icanon min 0 time 1")
+                 string))
 
 ;; We use BUFFER also as connection buffer during setup.  Because of
 ;; this, its original contents must be saved, and restored once
@@ -3089,12 +3098,21 @@ implementation will be used."
                               ;; otherwise strings larger than 4096
                               ;; bytes, sent by the process, could
                               ;; block, see termios(3) and Bug#61341.
+                              ;; In order to prevent blocking read
+                              ;; from pipe processes, "stty -icanon"
+                              ;; is used.  By default, it expects at
+                              ;; least one character to read.  When a
+                              ;; process does not read from stdin,
+                              ;; like magit, it should set a timeout
+                              ;; instead. See`tramp-pipe-stty-settings'.
+                              ;; (Bug#62093)
                               ;; FIXME: Shall we rather use "stty raw"?
-                              (if (tramp-check-remote-uname v "Darwin")
-                                  (tramp-send-command
-                                   v "stty -icanon min 1 time 0")
-                                (tramp-send-command
-                                 v "stty -icrnl -icanon min 1 time 0")))
+                              (tramp-send-command
+                               v (format
+                                  "stty %s %s"
+                                  (if (tramp-check-remote-uname v "Darwin")
+                                      "" "-icrnl")
+                                  tramp-pipe-stty-settings)))
                             ;; `tramp-maybe-open-connection' and
                             ;; `tramp-send-command-and-read' could
                             ;; have trashed the connection buffer.