checkdoc: Delete redundant check for wide docstrings

With Emacs 28.1, wide docstrings are now flagged by the byte-compiler.
The logic in the byte-compiler for catching these issues is complex
and continuously evolving, particularly to avoid incorrectly flagging
`substitute-command-keys` substitutions.  Unfortunately, the checkdoc
implementation incorrectly flags correct docstrings as overly wide.

Rather than duplicating the byte-compiler logic in checkdoc, which
would introduce unnecessary maintenance overhead, we acknowledge that
this check is now redundant and remove it.  Users utilizing the
byte-compiler, whether manually or through `flymake`, will continue to
be warned about this issue.

* lisp/emacs-lisp/checkdoc.el (checkdoc-this-string-valid-engine):
Remove check for overly wide docstrings; duplicates byte-compiler
logic.

2 files changed, 5 insertions, 29 deletions

diff --git a/etc/NEWS b/etc/NEWS
index c8797cf74ec..d90836b8c6d 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1025,6 +1025,11 @@ This change affects both 'M-x checkdoc' and the corresponding flymake
 backend.
 
 ---
+*** Checkdoc no longer warns about wide docstrings.
+The Checkdoc warning for wide docstrings duplicates the byte-compiler
+warning added in Emacs 28.1.  This redundancy is now removed.
+
+---
 *** New user option 'checkdoc-arguments-missing-flag'.
 Set this to nil to disable warnings for function arguments that are not
 documented in docstrings.
diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
index c5f1e9a6ed5..355a0c5e98a 100644
--- a/lisp/emacs-lisp/checkdoc.el
+++ b/lisp/emacs-lisp/checkdoc.el
@@ -1694,35 +1694,6 @@ function,command,variable,option or symbol." ms1))))))
          (if ret
              (checkdoc-create-error ret mb me)
            nil)))
-     ;; * Format the documentation string so that it fits in an
-     ;;   Emacs window on an 80-column screen.  It is a good idea
-     ;;   for most lines to be no wider than 60 characters.  The
-     ;;   first line can be wider if necessary to fit the
-     ;;   information that ought to be there.
-     (save-excursion
-       (let* ((start (point))
-              (eol nil)
-              ;; Respect this file local variable.
-              (max-column (max 80 byte-compile-docstring-max-column))
-              ;; Allow the first line to be three characters longer, to
-              ;; fit the leading ` "' while still having a docstring
-              ;; shorter than e.g. 80 characters.
-              (first t)
-              (get-max-column (lambda () (+ max-column (if first 3 0)))))
-         (while (and (< (point) e)
-                     (or (progn (end-of-line) (setq eol (point))
-                                (< (current-column) (funcall get-max-column)))
-                         (progn (beginning-of-line)
-                                (re-search-forward "\\\\\\\\[[<{]"
-                                                   eol t))
-                         (checkdoc-in-sample-code-p start e)))
-           (setq first nil)
-           (forward-line 1))
-         (end-of-line)
-         (if (and (< (point) e) (> (current-column) (funcall get-max-column)))
-             (checkdoc-create-error
-              (format "Some lines are over %d columns wide" max-column)
-              s (save-excursion (goto-char s) (line-end-position))))))
      ;; Here we deviate to tests based on a variable or function.
      ;; We must do this before checking for symbols in quotes because there
      ;; is a chance that just such a symbol might really be an argument.