Make TAGS files more portable to MS-Windows

* etc/NEWS: Document this.
* lib-src/etags.c (readline_internal) [DOS_NT]:
Don't treat CRs differently from GNUish hosts.
* lisp/progmodes/etags.el (etags-goto-tag-location):
Adjust STARTPOS to account for the skipped CRs in dos-style files.

1 files changed, 9 insertions, 2 deletions

diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index 60ea456d57c..9ff164e15ef 100644
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -1355,9 +1355,16 @@ hits the start of file."
             pat (concat (if (eq selective-display t)
                             "\\(^\\|\^m\\)" "^")
                         (regexp-quote (car tag-info))))
-      ;; The character position in the tags table is 0-origin.
+      ;; The character position in the tags table is 0-origin and counts CRs.
       ;; Convert it to a 1-origin Emacs character position.
-      (if startpos (setq startpos (1+ startpos)))
+      (when startpos
+        (setq startpos (1+ startpos))
+        (when (and line
+                   (eq 1 (coding-system-eol-type buffer-file-coding-system)))
+          ;; Act as if CRs were elided from all preceding lines.
+          ;; Although this doesn't always give exactly the correct position,
+          ;; it does typically improve the guess.
+          (setq startpos (- startpos (1- line)))))
       ;; If no char pos was given, try the given line number.
       (or startpos
           (if line