Subject: bug#51892: 29.0.50; [PATCH] Don't ignore restriction in indent-region-line-by-line

From: [email-masked]
Date: Tue, 16 Nov 2021 13:57:59 +0100

Emacs convention is that low-level functions should respect restriction
so that their callers can set restriction according to their needs. For
example, 'c-indent-region' is a lower-level function which respects the
current restriction and 'indent-region' is a higher-level user command
which sets the restriction for lower-level functions, it calls
"(widen)".

'indent-region-line-by-line' is a low-level function on a similar level
as 'c-indent-region'. This patch makes it respect the current
restriction instead of having it call "(widen)".

From bb388580fa7fa15be8aeabb9b80526fefbfac3aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miha=20Rihtar=C5=A1i=C4=8D?= <[email-masked]>
Date: Mon, 15 Nov 2021 17:57:36 +0100
Subject: [PATCH 1/6] Don't ignore restriction in indent-region-line-by-line

* lisp/indent.el (indent-according-to-mode): Don't widen if the new
optional argument is non-nil.
(indent-region): Explicitly widen before calling
indent-region-line-by-line.
(indent-region-line-by-line): Don't widen.
---
 lisp/indent.el | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/lisp/indent.el b/lisp/indent.el
index aa6b8d17c4..0a906fb526 100644
--- a/lisp/indent.el
+++ b/lisp/indent.el
@@ -88,16 +88,20 @@ indent-line-ignored-functions
                                         indent-relative-first-indent-point)
   "Values that are ignored by `indent-according-to-mode'.")
 
-(defun indent-according-to-mode ()
+(defun indent-according-to-mode (&optional dont-widen)
   "Indent line in proper way for current major mode.
 Normally, this is done by calling the function specified by the
 variable `indent-line-function'.  However, if the value of that
 variable is present in the `indent-line-ignored-functions' variable,
 handle it specially (since those functions are used for tabbing);
-in that case, indent by aligning to the previous non-blank line."
+in that case, indent by aligning to the previous non-blank line.
+
+Ignore restriction, unless the optional argument DONT-WIDEN is
+non-nil."
   (interactive)
   (save-restriction
-    (widen)
+    (unless dont-widen
+      (widen))
   (syntax-propertize (line-end-position))
   (if (memq indent-line-function indent-line-ignored-functions)
       ;; These functions are used for tabbing, but can't be used for
@@ -601,7 +605,10 @@ indent-region
       (funcall indent-region-function start end)))
    ;; Else, use a default implementation that calls indent-line-function on
    ;; each line.
-   (t (indent-region-line-by-line start end)))
+   (t
+    (save-restriction
+      (widen)
+      (indent-region-line-by-line start end))))
   ;; In most cases, reindenting modifies the buffer, but it may also
   ;; leave it unmodified, in which case we have to deactivate the mark
   ;; by hand.
@@ -615,7 +622,7 @@ indent-region-line-by-line
                 (make-progress-reporter "Indenting region..." (point) end))))
       (while (< (point) end)
         (or (and (bolp) (eolp))
-            (indent-according-to-mode))
+            (indent-according-to-mode t))
         (forward-line 1)
         (and pr (progress-reporter-update pr (point))))
       (and pr (progress-reporter-done pr))
-- 
2.33.1