(comint-next-prompt): Don't loop infinitely if

{next,previous}-single-char-property-change returns its input position
when the search fails.

diff --git a/lisp/comint.el b/lisp/comint.el
index 3b0ccfc..29897a9 100644 (file)
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -2140,14 +2140,21 @@ occurance of text matching `comint-prompt-regexp'."
        (comint-skip-prompt))
     ;; Use input fields
     (let ((pos (point))
-         (input-pos nil))
+         (input-pos nil)
+         prev-pos)
       (while (/= n 0)
+       (setq prev-pos pos)
        (setq pos
              (if (> n 0)
                  (next-single-char-property-change pos 'field)
                (previous-single-char-property-change pos 'field)))
-       (cond ((null pos)
+       (cond ((or (null pos) (= pos prev-pos))
               ;; Ran off the end of the buffer.
+              (when (> n 0)
+                ;; There's always an input field at the end of the
+                ;; buffer, but it has a `field' property of nil.
+                (setq input-pos (point-max)))
+              ;; stop iterating
               (setq n 0))
              ((eq (get-char-property pos 'field) 'input)
               (setq n (if (< n 0) (1+ n) (1- n)))