Fix bug#5620: recalculate all markers on compilation buffer

modifications, not on file modifications.
(buffer-modtime): New buffer-local variable:
the buffer modification time, for buffers not associated with files.
(compilation-mode): Create it.
(compilation-filter): Update it.
(compilation-next-error-function): Use it instead of
`visited-file-modtime' for timestamp.

2 files changed, 17 insertions, 3 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index c417eb7246e..6eb3260f445 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,14 @@
+2010-03-23  Sam Steingold  <sds@gnu.org>
+
+        Fix bug#5620: recalculate all markers on compilation buffer
+        modifications, not on file modifications.
+        * progmodes/compile.el (buffer-modtime): New buffer-local variable:
+        the buffer modification time, for buffers not associated with files.
+        (compilation-mode): Create it.
+        (compilation-filter): Update it.
+        (compilation-next-error-function): Use it instead of
+        `visited-file-modtime' for timestamp.
+
 2010-03-23  Juri Linkov  <juri@jurta.org>
 
         Implement Occur multi-line matches.
diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index 7e013b87c19..8a858d74dcd 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -733,6 +733,9 @@ Faces `compilation-error-face', `compilation-warning-face',
   "If non-nil, automatically jump to the next error encountered.")
 (make-variable-buffer-local 'compilation-auto-jump-to-next)
 
+(defvar buffer-modtime nil
+  "The buffer modification time, for buffers not associated with files.")
+(make-variable-buffer-local 'buffer-modtime)
 
 (defvar compilation-skip-to-next-location t
   "*If non-nil, skip multiple error messages for the same source location.")
@@ -1566,6 +1569,7 @@ Runs `compilation-mode-hook' with `run-mode-hooks' (which see).
         mode-name (or name-of-mode "Compilation"))
   (set (make-local-variable 'page-delimiter)
        compilation-page-delimiter)
+  (set (make-local-variable 'buffer-modtime) nil)
   (compilation-setup)
   (setq buffer-read-only t)
   (run-mode-hooks 'compilation-mode-hook))
@@ -1781,6 +1785,7 @@ and runs `compilation-filter-hook'."
               (unless comint-inhibit-carriage-motion
                 (comint-carriage-motion (process-mark proc) (point)))
               (set-marker (process-mark proc) (point))
+              (set (make-local-variable buffer-modtime) (current-time))
               (run-hooks 'compilation-filter-hook))
           (goto-char pos)
           (narrow-to-region min max)
@@ -1954,9 +1959,7 @@ This is the value of `next-error-function' in Compilation buffers."
                  ;; There may be no timestamp info if the loc is a `fake-loc',
                  ;; but we just checked that the file has been visited before!
                  (equal (nth 4 loc)
-                        (setq timestamp
-                              (with-current-buffer (marker-buffer (nth 3 loc))
-                                (visited-file-modtime)))))
+                        (setq timestamp buffer-modtime)))
       (with-current-buffer (compilation-find-file marker (caar (nth 2 loc))
                                                   (cadr (car (nth 2 loc))))
         (save-restriction