bug#73771: 30.0.91; etags generates broken TAGS file for multi-line regex match

["Francesco Potortì" <pot@gnu.org>]

>This is because etags always records one extra character with the
>regexp match, which is harmless, unless that extra character is a
>newline.  The patch below fixes it:
>
>diff --git a/lib-src/etags.c b/lib-src/etags.c
>index a822a82..848d8ea 100644
>--- a/lib-src/etags.c
>+++ b/lib-src/etags.c
>@@ -7420,7 +7420,7 @@ regex_tag_multiline (void)
> 
> 	      /* Force explicit tag name, if a name is there. */
> 	      pfnote (name, true, buffer + linecharno,
>-		      charno - linecharno + 1, lineno, linecharno);
>+		      charno - linecharno, lineno, linecharno);
> 
> 	      if (debug)
> 		fprintf (stderr, "%s on %s:%"PRIdMAX": %s\n",
>
>Francesco, why does the code add one more character there?

While I can't remember the reason, I am sure it was not done by chance.

Sure, I may have been wrong at that time, or maybe that reason is now obsolete.  To check, one should run the etags regression test and check the results.

Off the top of my head, it may have to do with implicitly named tags that are initial substring of a different tag, but this may be a fake reconstruction of my mind,