Fix encoding and decoding of process I/O in Eshell on Windows

* lisp/eshell/esh-proc.el (eshell-gather-process-output): Set up
encoding and decoding of text to/from the subprocess for
MS-Windows.  (Bug#58281)

1 files changed, 17 insertions, 1 deletions

diff --git a/lisp/eshell/esh-proc.el b/lisp/eshell/esh-proc.el
index 7e005a0fc1c..bb928fc5fb0 100644
--- a/lisp/eshell/esh-proc.el
+++ b/lisp/eshell/esh-proc.el
@@ -277,7 +277,23 @@ Used only on systems which do not support async subprocesses.")
               eshell-delete-exited-processes
             delete-exited-processes))
          (process-environment (eshell-environment-variables))
+         (coding-system-for-read coding-system-for-read)
+         (coding-system-for-write coding-system-for-write)
          proc stderr-proc decoding encoding changed)
+    ;; MS-Windows needs special setting of encoding/decoding, because
+    ;; (a) non-ASCII text in command-line arguments needs to be
+    ;; encoded in the system's codepage; and (b) because many Windows
+    ;; programs will always interpret any non-ASCII input as encoded
+    ;; in the system codepage.
+    (when (eq system-type 'windows-nt)
+      (or coding-system-for-read        ; Honor manual decoding settings
+          (setq coding-system-for-read
+                (coding-system-change-eol-conversion locale-coding-system
+                                                     'dos)))
+      (or coding-system-for-write       ; Honor manual encoding settings
+          (setq coding-system-for-write
+                (coding-system-change-eol-conversion locale-coding-system
+                                                     'unix))))
     (cond
      ((fboundp 'make-process)
       (unless (equal (car (aref eshell-current-handles eshell-output-handle))
@@ -325,7 +341,7 @@ Used only on systems which do not support async subprocesses.")
             (setq decoding (coding-system-change-eol-conversion decoding 'dos)
                   changed t))
         ;; Even if `make-process' left the coding system for encoding
-        ;; data sent from the process undecided, we had better use the
+        ;; data sent to the process undecided, we had better use the
         ;; same one as what we use for decoding.  But, we should
         ;; suppress EOL conversion.
         (if (and decoding (not encoding))