Fix column double counting in term.el (Bug#31662)

* lisp/term.el (term-emulate-terminal): Invalidate
`term-current-column' after deleting overwritten text.

lisp/term.el

@@ -2904,7 +2904,8 @@ See `term-prompt-regexp'."
                   (when (not (or (eobp) term-insert-mode))
                     (let ((pos (point)))
                       (term-move-columns columns)
-                      (delete-region pos (point))))
+                      (delete-region pos (point))
+                      (setq term-current-column nil)))
                   ;; In insert mode if the current line
                   ;; has become too long it needs to be
                   ;; chopped off.

test/lisp/term-tests.el

@@ -89,6 +89,13 @@ first line\r_next line\r\n"))
                                               "\e[2;1Hc"
                                               "\e[1;2Hb"
                                               "\e[1;1Ha") "" t))))
+  (should (equal "abcde    j"
+                 (term-test-screen-from-input
+                  10 12 '("abcdefghij"
+                          "\e[H"  ;move back to point-min
+                          "abcde"
+                          "    j"))))
+
   ;; Relative positioning.
   (should (equal "ab\ncd"
                  (term-test-screen-from-input