Subject: bug#15418: 24.3.50; RCS annotate broken in vc-rcs.el r114131

From: Stefan Monnier <[email-masked]>
Date: Thu, 19 Sep 2013 17:26:06 -0400

>>>>> "Richard" == Richard Copley <[email-masked]> writes:

> For some files under RCS version control, `vc-annotate' now fails with
> error `(wrong-type-argument integer-or-marker-p nil)'.

> I think the problem is with the variable `b' whose dynamic binding
> was used by `gather' and set by `incg' (local functions in
> `vc-rcs-parse'), prior to r114131.

Indeed, it seems like there was some subtle dynamic scoping at play.
Does the patch below fix your problem?

        Stefan

=== modified file 'lisp/vc/vc-rcs.el'
--- lisp/vc/vc-rcs.el	2013-09-04 21:09:42 +0000
+++ lisp/vc/vc-rcs.el	2013-09-19 21:24:53 +0000
@@ -1234,6 +1234,8 @@
   (vc-do-command "*vc*" 0 "rcs" (vc-name file) (concat "-b" branch))
   (vc-file-setprop file 'vc-rcs-default-branch branch))
 
+(defvar vc-rcs--b)
+
 (defun vc-rcs-parse (&optional buffer)
   "Parse current buffer, presumed to be in RCS-style masterfile format.
 Optional arg BUFFER specifies another buffer to parse.  Return an alist
@@ -1314,7 +1316,7 @@
         tok
         ;; Region (begin and end buffer positions) of the printed
         ;; representation for the current tag.
-        b e
+        vc-rcs--b e
         ;; A list of buffer positions where "@@" can be found within the
         ;; printed representation region.  For each location, we push two
         ;; elements onto the list, 1+ and 2+ the location, respectively,
@@ -1330,11 +1332,11 @@
          (to-eol () (buffer-substring-no-properties
                      (point) (progn (forward-line 1)
                                     (1- (point)))))
-         (to-semi () (setq b (point)
+         (to-semi () (setq vc-rcs--b (point)
                            e (progn (search-forward ";")
                                     (1- (point)))))
          (to-one@ () (setq @-holes nil
-                           b (progn (search-forward "@") (point))
+                           vc-rcs--b (progn (search-forward "@") (point))
                            e (progn (while (and (search-forward "@")
                                                 (= ?@ (char-after))
                                                 (progn
@@ -1349,9 +1351,9 @@
                   (funcall set-b+e)
                   (cons tok (if proc
                                 (funcall proc)
-                              (buffer-substring-no-properties b e))))
+                              (buffer-substring-no-properties vc-rcs--b e))))
          (k-semi (name &optional proc) (tok+val #'to-semi name proc))
-         (gather () (let ((pairs `(,e ,@@-holes ,b))
+         (gather () (let ((pairs `(,e ,@@-holes ,vc-rcs--b))
                           acc)
                       (while pairs
                         (push (buffer-substring-no-properties
@@ -1381,7 +1383,7 @@
                                (setcdr two (cadr two))
                                two))
                            (split-string
-                            (buffer-substring-no-properties b e)))))
+                            (buffer-substring-no-properties vc-rcs--b e)))))
           (hpush 'locks))
         (push `(strict . ,(when (at 'strict)
                             (search-forward ";")
@@ -1403,7 +1405,7 @@
                              (let ((ls (mapcar 'string-to-number
                                                (split-string
                                                 (buffer-substring-no-properties
-                                                 b e)
+                                                 vc-rcs--b e)
                                                 "\\."))))
                                ;; Hack the year -- verified to be the
                                ;; same algorithm used in RCS 5.7.
@@ -1414,7 +1416,7 @@
                   ,(k-semi 'branches
                            (lambda ()
                              (split-string
-                              (buffer-substring-no-properties b e))))
+                              (buffer-substring-no-properties vc-rcs--b e))))
                   ,(k-semi 'next))
                 revs)
           (sw))
@@ -1440,8 +1442,8 @@
               ;; only the former since it behaves identically to the
               ;; latter in the absence of "@@".)
               sub)
-          (cl-flet ((incg (_beg end)
-                          (let ((e end) @-holes)
+          (cl-flet ((incg (beg end)
+                          (let ((vc-rcs--b beg) (e end) @-holes)
                             (while (and asc (< (car asc) e))
                               (push (pop asc) @-holes))
                             ;; Self-deprecate when work is done.
@@ -1471,7 +1473,7 @@
                     (setq asc (nreverse @-holes)
                           sub #'incg)
                   (setq sub #'buffer-substring-no-properties))
-                (goto-char b)
+                (goto-char vc-rcs--b)
                 (setq acc nil)
                 (while (< (point) e)
                   (forward-char 1)