bug#31984: 26.1.50; IELM doesn't indent results printed with #

[Noam Postavsky]

tags 31984 + patch
quit

Noam Postavsky <npostavs@gmail.com> writes:

> With point before the (foo), Emacs 25 indent-sexp turns this
>
> (foo) (blah
> etc)
>
> into this
>
> (foo) (blah
>        etc)
>
> Emacs 26 indent-sexp doesn't do anything from that position.  It's less
> clear which is correct in that case, but restoring to the Emacs 25
> behaviour would fix the #s(...) case as well.  Alternatively, we could
> fix elisp sexp movement to handle such expressions, which we should
> probably do anyway (see also Bug#15998).

Probably Bug#15998 won't be fixed in Emacs 26, so here's a patch to make
indent-sexp indent the sexp spanning the end of line, like Emacs 25
does.

>From 3e206ed6c2c82ef3d147b3dece6dc65ffe1625a2 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Thu, 19 Jul 2018 06:40:54 -0400
Subject: [PATCH] Fix indent-sexp of #s(...) (Bug#31984)

* lisp/emacs-lisp/lisp-mode.el (indent-sexp): Look for a sexp that
ends after the current line.
* test/lisp/emacs-lisp/lisp-mode-tests.el (indent-sexp-go): New test.
---
 lisp/emacs-lisp/lisp-mode.el            | 10 ++++++++--
 test/lisp/emacs-lisp/lisp-mode-tests.el | 12 ++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index 3a03b56313..44b27236a9 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -1199,8 +1199,14 @@ indent-sexp
     (setq endpos (copy-marker
                   (if endpos endpos
                     ;; Get error now if we don't have a complete sexp
-                    ;; after point.
-                    (save-excursion (forward-sexp 1) (point)))))
+                    ;; after point.  We actually look for a sexp which
+                    ;; ends after the current line so that we properly
+                    ;; indent things like #s(...).  This might not be
+                    ;; needed if Bug#15998 is fixed.
+                    (let ((eol (line-end-position)))
+                      (save-excursion (while (and (< (point) eol) (not (eobp)))
+                                        (forward-sexp 1))
+                                      (point))))))
     (save-excursion
       (while (let ((indent (lisp-indent-calc-next parse-state))
                    (ppss (lisp-indent-state-ppss parse-state)))
diff --git a/test/lisp/emacs-lisp/lisp-mode-tests.el 
b/test/lisp/emacs-lisp/lisp-mode-tests.el
index 8598d41978..0b052e9fc3 100644
--- a/test/lisp/emacs-lisp/lisp-mode-tests.el
+++ b/test/lisp/emacs-lisp/lisp-mode-tests.el
@@ -113,6 +113,18 @@ lisp-mode-tests--correctly-indented-sexp
       ;; we're indenting ends on the previous line.
       (should (equal (buffer-string) original)))))
 
+(ert-deftest indent-sexp-go ()
+  "Make sure `indent-sexp' doesn't stop after #s."
+  ;; See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=31984.
+  (with-temp-buffer
+    (emacs-lisp-mode)
+    (insert "#s(foo\nbar)\n")
+    (goto-char (point-min))
+    (indent-sexp)
+    (should (equal (buffer-string) "\
+#s(foo
+   bar)\n"))))
+
 (ert-deftest lisp-indent-region ()
   "Test basics of `lisp-indent-region'."
   (with-temp-buffer
-- 
2.11.0