Fix Meta key combinations not forwarded to terminal

M-f, M-b, M-d etc. were intercepted by Emacs global bindings
(forward-word, backward-word, kill-word) instead of being sent to the
terminal. Two fixes: bind M-<letter> keys in ghostel-mode-map via
ghostel--send-event, and add ESC+char fallback in
ghostel--raw-key-sequence for when the native encoder doesn't produce
output.

Fix #48

Author: dakra

ghostel.el

@@ -621,6 +621,12 @@ Used for prompt navigation and optional re-application after full redraws.")
                         (let ((code (- c 96)))
                           (lambda () (interactive)
                             (ghostel--send-key (string code)))))))))
+    ;; Meta keys — bind all M-<letter> so they reach the terminal
+    ;; instead of running Emacs commands like forward-word.
+    (dolist (c (number-sequence ?a ?z))
+      (let ((key-str (format "M-%c" c)))
+        (unless (member key-str ghostel-keymap-exceptions)
+          (define-key map (kbd key-str) #'ghostel--send-event))))
     ;; C-@ (NUL, same as C-SPC) — used by programs like Emacs-in-terminal
     (define-key map (kbd "C-@")
                 (lambda () (interactive) (ghostel--send-key "\x00")))
@@ -749,6 +755,11 @@ Returns the sequence string, or nil for unknown keys."
            (<= ?a (aref key-name 0)) (<= (aref key-name 0) ?z)
            (> (logand mod-num 4) 0))        ; ctrl bit
       (string (- (aref key-name 0) 96)))    ; ctrl-a=1, ctrl-z=26
+     ;; Meta + single letter → ESC + char
+     ((and (= (length key-name) 1)
+           (<= ?a (aref key-name 0)) (<= (aref key-name 0) ?z)
+           (> (logand mod-num 2) 0))        ; alt/meta bit
+      (format "\e%c" (aref key-name 0)))
      ;; Simple special keys (CSI u encoding for modified variants)
      ((string= key-name "backspace") (if (> mod-num 0) (format "\e[127;%du" (1+ mod-num)) "\x7f"))
      ((string= key-name "return")    (if (> mod-num 0) (format "\e[13;%du" (1+ mod-num)) "\r"))

test/ghostel-test.el

@@ -1430,6 +1430,19 @@ cell, so the visual line width must equal the terminal column count."
   ;; C-@ should also be bound (sends NUL)
   (should (lookup-key ghostel-mode-map (kbd "C-@"))))
 
+(ert-deftest ghostel-test-meta-key-bindings ()
+  "All non-exception M-<letter> keys should be bound in ghostel-mode-map."
+  (dolist (c (number-sequence ?a ?z))
+    (let* ((key-str (format "M-%c" c))
+           (key-vec (kbd key-str))
+           (binding (lookup-key ghostel-mode-map key-vec)))
+      (unless (eq c ?y)  ; M-y is ghostel-yank-pop
+        (if (member key-str ghostel-keymap-exceptions)
+            (should-not (eq binding #'ghostel--send-event))
+          (should (eq binding #'ghostel--send-event))))))
+  ;; M-y should be bound to ghostel-yank-pop, not send-event
+  (should (eq (lookup-key ghostel-mode-map (kbd "M-y")) #'ghostel-yank-pop)))
+
 (defconst ghostel-test--elisp-tests
   '(ghostel-test-raw-key-sequences
     ghostel-test-modifier-number
@@ -1458,7 +1471,8 @@ cell, so the visual line width must equal the terminal column count."
     ghostel-test-input-flush-sends-buffered
     ghostel-test-send-encoded-sets-send-time
     ghostel-test-send-encoded-no-send-time-on-fallback
-    ghostel-test-control-key-bindings)
+    ghostel-test-control-key-bindings
+    ghostel-test-meta-key-bindings)
   "Tests that require only Elisp (no native module).")
 
 (defun ghostel-test-run-elisp ()