Prefer `write-region' to `save-file'

* lisp/ob-haskell.el (org-babel-haskell-export-to-lhs): Use
non-interactive `insert-file-contents' + `write-region' to avoid
triggering various interactive hooks.  Ensure that temp files are
always deleted.
* lisp/org-agenda.el (org-agenda-write):
* lisp/org-table.el: Simplify code using `write-region'.
* lisp/ox-odt.el (org-odt-template): Use `insert-file-contents' +
`write-region' instead of `find-file-noselect' that may trigger
various hooks.  The new approach makes `revert-buffer' not
necessary (and do not trigger `revert-buffer' hooks).  Also, the
problem with backups will no longer exists.

Original idea: https://list.orgmode.org/orgmode/20221002035931.12191-1-dafydd.lukes@gmail.com/

lisp/ob-haskell.el

@@ -255,26 +255,27 @@ constructs (header arguments, no-web syntax etc...) are ignored."
                        t t)
         (indent-code-rigidly (match-beginning 0) (match-end 0) indentation)))
     (save-excursion
-      ;; export to latex w/org and save as .lhs
+      (unwind-protect
+          (with-temp-buffer
+            ;; Export to latex w/org and save as .lhs
             (require 'ox-latex)
-      (find-file tmp-org-file)
+            (insert-file-contents tmp-org-file)
             ;; Ensure we do not clutter kill ring with incomplete results.
             (let (org-export-copy-to-kill-ring)
-	(org-export-to-file 'latex tmp-tex-file))
+	      (org-export-to-file 'latex tmp-tex-file)))
-      (kill-buffer nil)
+        (delete-file tmp-org-file))
-      (delete-file tmp-org-file)
+      (unwind-protect
-      (find-file tmp-tex-file)
+          (with-temp-buffer
+            (insert-file-contents tmp-tex-file)
             (goto-char (point-min)) (forward-line 2)
             (insert "%include polycode.fmt\n")
             ;; ensure all \begin/end{code} statements start at the first column
             (while (re-search-forward "^[ \t]+\\\\begin{code}[^\000]+\\\\end{code}" nil t)
               (replace-match (save-match-data (org-remove-indentation (match-string 0)))
                              t t))
-      (setq contents (buffer-string))
-      (save-buffer) (kill-buffer nil))
-    (delete-file tmp-tex-file)
             ;; save org exported latex to a .lhs file
-    (with-temp-file lhs-file (insert contents))
+            (write-region nil nil lhs-file))
+        (delete-file tmp-tex-file)))
     (if (not arg)
         (find-file lhs-file)
       ;; process .lhs file with lhs2tex

lisp/org-agenda.el

@@ -3667,13 +3667,8 @@ the agenda to write."
 	                        "ox-icalendar" (file))
 	      (org-icalendar-export-current-agenda (expand-file-name file)))
 	     (t
-	      (let ((bs (buffer-string)))
+              (write-region nil nil file)
-		(find-file file)
+              (message "Plain text written to %s" file)))))))
-		(erase-buffer)
-		(insert bs)
-		(save-buffer 0)
-		(kill-buffer (current-buffer))
-		(message "Plain text written to %s" file))))))))
     (set-buffer (or agenda-bufname
 		    ;; FIXME: I'm pretty sure called-interactively-p
                     ;; doesn't do what we want here!

lisp/org-table.el

@@ -4332,14 +4332,8 @@ extension of the given file name, and finally on the variable
 		(table (org-table-to-lisp)))
 	    (unless (fboundp transform)
 	      (user-error "No such transformation function %s" transform))
-	    (let (buf)
+            (with-temp-file file
-	      (with-current-buffer (find-file-noselect file)
+              (insert (funcall transform table params) "\n"))
-		(setq buf (current-buffer))
-		(erase-buffer)
-		(fundamental-mode)
-		(insert (funcall transform table params) "\n")
-		(save-buffer))
-	      (kill-buffer buf))
 	    (message "Export done."))
 	(user-error "TABLE_EXPORT_FORMAT invalid")))))
 

lisp/ox-odt.el

@@ -1365,10 +1365,10 @@ original parsed data.  INFO is a plist holding export options."
     ;; Ensure we have write permissions to this file.
     (set-file-modes (concat org-odt-zip-dir "styles.xml") #o600)
 
-    ;; FIXME: Who is opening an empty styles.xml before this point?
+    (let ((styles-xml (concat org-odt-zip-dir "styles.xml")))
-    (with-current-buffer
+      (with-temp-buffer
-	(find-file-noselect (concat org-odt-zip-dir "styles.xml") t)
+        (when (file-exists-p styles-xml)
-      (revert-buffer t t)
+          (insert-file-contents styles-xml))
         
         ;; Write custom styles for source blocks
         ;; Save STYLES used for colorizing of source blocks.
@@ -1383,32 +1383,22 @@ original parsed data.  INFO is a plist holding export options."
 	      (insert "\n<!-- Org Htmlfontify Styles -->\n" styles "\n"))))
 
         ;; Update styles.xml - take care of outline numbering
-
-      ;; Don't make automatic backup of styles.xml file. This setting
-      ;; prevents the backed-up styles.xml file from being zipped in to
-      ;; odt file. This is more of a hackish fix. Better alternative
-      ;; would be to fix the zip command so that the output odt file
-      ;; includes only the needed files and excludes any auto-generated
-      ;; extra files like backups and auto-saves etc etc. Note that
-      ;; currently the zip command zips up the entire temp directory so
-      ;; that any auto-generated files created under the hood ends up in
-      ;; the resulting odt file.
-      (setq-local backup-inhibited t)
-
         ;; Outline numbering is retained only up to LEVEL.
         ;; To disable outline numbering pass a LEVEL of 0.
 
-      (goto-char (point-min))
         (let ((regex
 	       "<text:outline-level-style\\([^>]*\\)text:level=\"\\([^\"]*\\)\"\\([^>]*\\)>")
 	      (replacement
 	       "<text:outline-level-style\\1text:level=\"\\2\" style:num-format=\"\">"))
+          (goto-char (point-min))
           (while (re-search-forward regex nil t)
 	    (unless (let ((sec-num (plist-get info :section-numbers))
 		          (level (string-to-number (match-string 2))))
 		      (if (wholenump sec-num) (<= level sec-num) sec-num))
 	      (replace-match replacement t nil))))
-      (save-buffer 0)))
+        
+        ;; Write back the new contents.
+        (write-region nil nil styles-xml))))
   ;; Update content.xml.
 
   (let* ( ;; `org-display-custom-times' should be accessed right