emacs: Use 'when' instead of 'if' when there is no ELSE part

emacs/notmuch-address.el

@@ -171,7 +171,7 @@ toggles the setting in this buffer."
   (if (local-variable-p 'notmuch-address-command)
       (kill-local-variable 'notmuch-address-command)
     (notmuch-setq-local notmuch-address-command 'internal))
-  (if (boundp 'company-idle-delay)
+  (when (boundp 'company-idle-delay)
     (if (local-variable-p 'company-idle-delay)
 	(kill-local-variable 'company-idle-delay)
       (notmuch-setq-local company-idle-delay nil))))

emacs/notmuch-compat.el

@@ -68,7 +68,7 @@ inlined."
 		   ;; This is an inlined copy of help-form-show as that
 		   ;; was introduced in emacs 24 too.
 		   (let ((msg (eval help-form)))
-		     (if (stringp msg)
+		     (when (stringp msg)
 		       (with-output-to-temp-buffer " *Char Help*"
 			 (princ msg))))))
 	     ((memq char chars)

emacs/notmuch-hello.el

@@ -589,7 +589,7 @@ with `notmuch-hello-query-counts'."
     (mapc (lambda (elem)
 	    ;; (not elem) indicates an empty slot in the matrix.
 	    (when elem
-	      (if (> column-indent 0)
+	      (when (> column-indent 0)
 		(widget-insert (make-string column-indent ? )))
 	      (let* ((name (plist-get elem :name))
 		     (query (plist-get elem :query))
@@ -890,7 +890,7 @@ Supports the following entries in OPTIONS as a plist:
    the same values as :filter. If :filter and :filter-count are specified, this
    will be used instead of :filter, not in conjunction with it."
   (widget-insert title ": ")
-  (if (and notmuch-hello-first-run (plist-get options :initially-hidden))
+  (when (and notmuch-hello-first-run (plist-get options :initially-hidden))
     (add-to-list 'notmuch-hello-hidden-sections title))
   (let ((is-hidden (member title notmuch-hello-hidden-sections))
 	(start (point)))

emacs/notmuch-jump.el

@@ -169,7 +169,7 @@ buffer."
   (let ((map (make-sparse-keymap)))
     (set-keymap-parent map notmuch-jump-minibuffer-map)
     (pcase-dolist (`(,key ,name ,fn) action-map)
-      (if (= (length key) 1)
+      (when (= (length key) 1)
 	(define-key map key
 	  `(lambda () (interactive)
 	     (setq notmuch-jump--action ',fn)
@@ -178,7 +178,7 @@ buffer."
     ;; binding) we avoid problems if the user specifies a binding which
     ;; is a prefix of another binding.
     (pcase-dolist (`(,key ,name ,fn) action-map)
-      (if (> (length key) 1)
+      (when (> (length key) 1)
 	(let* ((key (elt key 0))
 	       (keystr (string key))
 	       (new-prompt (concat prompt (format-kbd-macro keystr) " "))

emacs/notmuch-lib.el

@@ -664,7 +664,7 @@ MSG (if it isn't already)."
 ;; first loading gnus-art, which defines it, resulting in a
 ;; void-variable error.  Hence, we advise `mm-shr' to ensure gnus-art
 ;; is loaded.
-(if (>= emacs-major-version 24)
+(when (>= emacs-major-version 24)
   (defadvice mm-shr (before load-gnus-arts activate)
     (require 'gnus-art nil t)
     (ad-disable-advice 'mm-shr 'before 'load-gnus-arts)

emacs/notmuch-mua.el

@@ -275,7 +275,7 @@ Typically this is added to `notmuch-mua-send-hook'."
 	(narrow-to-region (point) (point-max))
 	(goto-char (point-max))
 	(if (re-search-backward message-signature-separator nil t)
-	    (if message-signature-insert-empty-line
+	    (when message-signature-insert-empty-line
 	      (forward-line -1))
 	  (goto-char (point-max))))
       (let ((from (plist-get original-headers :From))
@@ -388,7 +388,8 @@ modified. This function is notmuch addaptation of
 	  ;; https://lists.gnu.org/archive/html/emacs-devel/2011-01/msg00337.html
 	  ;; We need to convert any string input, eg from rmail-start-mail.
 	  (dolist (h other-headers other-headers)
-	    (if (stringp (car h)) (setcar h (intern (capitalize (car h))))))))
+	    (when (stringp (car h))
+	      (setcar h (intern (capitalize (car h))))))))
 	(args (list yank-action send-actions))
 	;; Cause `message-setup-1' to do things relevant for mail,
 	;; such as observe `message-default-mail-headers'.
@@ -428,7 +429,8 @@ the From: header is already filled in by notmuch."
 ;; without some explicit initialization fill freeze the operation.
 ;; Hence, we advice `ido-completing-read' to ensure required initialization
 ;; is done.
-(if (and (= emacs-major-version 23) (< emacs-minor-version 4))
+(when (and (= emacs-major-version 23)
+	   (< emacs-minor-version 4))
   (defadvice ido-completing-read (before notmuch-ido-mode-init activate)
     (ido-init-completion-maps)
     (add-hook 'minibuffer-setup-hook 'ido-minibuffer-setup)

emacs/notmuch-query.el

@@ -30,7 +30,7 @@ A thread is a forest or list of trees. A tree is a two element
 list where the first element is a message, and the second element
 is a possibly empty forest of replies."
   (let ((args '("show" "--format=sexp" "--format-version=4")))
-    (if notmuch-show-process-crypto
+    (when notmuch-show-process-crypto
       (setq args (append args '("--decrypt=true"))))
     (setq args (append args search-terms))
     (apply #'notmuch-call-notmuch-sexp args)))

emacs/notmuch-show.el

@@ -346,7 +346,7 @@ operation on the contents of the current buffer."
 	 (indenting notmuch-show-indent-content))
     (with-temp-buffer
       (insert all)
-      (if indenting
+      (when indenting
 	(indent-rigidly (point-min)
 			(point-max)
 			(- (* notmuch-show-indent-messages-width depth))))
@@ -392,7 +392,7 @@ operation on the contents of the current buffer."
   "Update the displayed tags of the current message."
   (save-excursion
     (goto-char (notmuch-show-message-top))
-    (if (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
+    (when (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
       (let ((inhibit-read-only t))
 	(replace-match (concat "("
 			       (notmuch-tag-format-tags
@@ -488,7 +488,7 @@ message at DEPTH in the current thread."
     (mapc (lambda (header)
 	    (let* ((header-symbol (intern (concat ":" header)))
 		   (header-value (plist-get headers header-symbol)))
-	      (if (and header-value
+	      (when (and header-value
 			 (not (string-equal "" header-value)))
 		(notmuch-show-insert-header header header-value))))
 	  notmuch-message-headers)
@@ -606,10 +606,10 @@ will return nil if the CID is unknown or cannot be retrieved."
 (defun notmuch-show-setup-w3m ()
   "Instruct w3m how to retrieve content from a \"related\" part of a message."
   (interactive)
-  (if (boundp 'w3m-cid-retrieve-function-alist)
-      (unless (assq 'notmuch-show-mode w3m-cid-retrieve-function-alist)
+  (when (and (boundp 'w3m-cid-retrieve-function-alist)
+	     (not (assq 'notmuch-show-mode w3m-cid-retrieve-function-alist)))
     (push (cons 'notmuch-show-mode #'notmuch-show--cid-w3m-retrieve)
-	      w3m-cid-retrieve-function-alist)))
+	  w3m-cid-retrieve-function-alist))
   (setq mm-html-inhibit-images nil))
 
 (defvar w3m-current-buffer) ;; From `w3m.el'.
@@ -767,7 +767,7 @@ will return nil if the CID is unknown or cannot be retrieved."
 (defun notmuch-show-insert-part-text/x-vcalendar (msg part content-type nth depth button)
   (notmuch-show-insert-part-text/calendar msg part content-type nth depth button))
 
-(if (version< emacs-version "25.3")
+(when (version< emacs-version "25.3")
   ;; https://bugs.gnu.org/28350
   ;;
   ;; For newer emacs, we fall back to notmuch-show-insert-part-*/*
@@ -849,7 +849,7 @@ will return nil if the CID is unknown or cannot be retrieved."
   "Return a list of content handlers for a part of type CONTENT-TYPE."
   (let (result)
     (mapc (lambda (func)
-	    (if (functionp func)
+	    (when (functionp func)
 	      (push func result)))
 	  ;; Reverse order of prefrence.
 	  (list (intern (concat "notmuch-show-insert-part-*/*"))
@@ -1080,7 +1080,7 @@ is t, hide the part initially and show the button."
       (insert "\n"))
     (setq content-end (point-marker))
     ;; Indent according to the depth in the thread.
-    (if notmuch-show-indent-content
+    (when notmuch-show-indent-content
       (indent-rigidly content-start
 		      content-end
 		      (* notmuch-show-indent-messages-width depth)))
@@ -1288,7 +1288,8 @@ and THREAD.  The next query is THREAD alone, and serves as a
 fallback if the prior matches no messages."
   (let (queries)
     (push (list thread) queries)
-    (if context (push (list thread "and (" context ")") queries))
+    (when context
+      (push (list thread "and (" context ")") queries))
     queries))
 
 (defun notmuch-show--build-buffer (&optional state)
@@ -1785,7 +1786,7 @@ Reshows the current thread with matches defined by the new query-string."
     (let (message-ids done)
       (goto-char (point-min))
       (while (not done)
-	(if (notmuch-show-message-visible-p)
+	(when (notmuch-show-message-visible-p)
 	  (setq message-ids
 		(append message-ids (list (notmuch-show-get-message-id)))))
 	(setq done (not (notmuch-show-goto-message-next))))
@@ -1842,7 +1843,7 @@ archives the entire current thread, (apply changes in
 thread from the search from which this thread was originally
 shown."
   (interactive)
-  (if (notmuch-show-advance)
+  (when (notmuch-show-advance)
     (notmuch-show-archive-thread-then-next)))
 
 (defun notmuch-show-rewind ()

emacs/notmuch-tree.el

@@ -967,13 +967,13 @@ Complete list of currently available key bindings:
 	(never-found-target-thread nil))
     (when (memq status '(exit signal))
       (kill-buffer (process-get proc 'parse-buf))
-      (if (buffer-live-p buffer)
+      (when (buffer-live-p buffer)
 	(with-current-buffer buffer
 	  (save-excursion
 	    (let ((inhibit-read-only t)
 		  (atbob (bobp)))
 	      (goto-char (point-max))
-		(if (eq status 'signal)
+	      (when (eq status 'signal)
 		(insert "Incomplete search results (tree view process was killed).\n"))
 	      (when (eq status 'exit)
 		(insert "End of search results.")
@@ -1023,7 +1023,7 @@ the same as for the function notmuch-tree."
 			      (and query-context
 				   (concat " and (" query-context ")"))))
 	 (message-arg (if unthreaded "--unthreaded" "--entire-thread")))
-    (if (equal (car (process-lines notmuch-command "count" search-args)) "0")
+    (when (equal (car (process-lines notmuch-command "count" search-args)) "0")
       (setq search-args basic-query))
     (notmuch-tag-clear-cache)
     (let ((proc (notmuch-start-notmuch

emacs/notmuch-wash.el

@@ -216,7 +216,7 @@ that PREFIX should not include a newline."
     (goto-char (1+ end))
     (save-excursion
       (goto-char beg)
-      (if prefix
+      (when prefix
 	(insert-before-markers prefix))
       (let ((button-beg (point)))
 	(insert-before-markers (notmuch-wash-button-label overlay) "\n")
@@ -229,7 +229,7 @@ that PREFIX should not include a newline."
   "Excerpt citations and up to one signature."
   (goto-char (point-min))
   (beginning-of-line)
-  (if (and (< (point) (point-max))
+  (when (and (< (point) (point-max))
 	     (re-search-forward notmuch-wash-original-regexp nil t))
     (let* ((msg-start (match-beginning 0))
 	   (msg-end (point-max))
@@ -254,12 +254,12 @@ that PREFIX should not include a newline."
 	  (notmuch-wash-region-to-button
 	   msg hidden-start (point-marker)
 	   "citation")))))
-  (if (and (not (eobp))
+  (when (and (not (eobp))
 	     (re-search-forward notmuch-wash-signature-regexp nil t))
     (let* ((sig-start (match-beginning 0))
 	   (sig-end (match-end 0))
 	   (sig-lines (count-lines sig-start (point-max))))
-	(if (<= sig-lines notmuch-wash-signature-lines-max)
+      (when (<= sig-lines notmuch-wash-signature-lines-max)
 	(let ((sig-start-marker (make-marker))
 	      (sig-end-marker (make-marker)))
 	  (set-marker sig-start-marker sig-start)
@@ -286,11 +286,11 @@ that PREFIX should not include a newline."
     (delete-region (match-beginning 1) (match-end 1)))
   ;; Remove a leading blank line.
   (goto-char (point-min))
-  (if (looking-at "\n")
+  (when (looking-at "\n")
     (delete-region (match-beginning 0) (match-end 0)))
   ;; Remove a trailing blank line.
   (goto-char (point-max))
-  (if (looking-at "\n")
+  (when (looking-at "\n")
     (delete-region (match-beginning 0) (match-end 0))))
 
 ;;
@@ -399,7 +399,7 @@ for error."
 	  (patch-end (point-max))
 	  part)
       (goto-char patch-start)
-      (if (or
+      (when (or
 	     ;; Patch ends with signature.
 	     (re-search-forward notmuch-wash-signature-regexp nil t)
 	     ;; Patch ends with bugtraq comment.

emacs/notmuch.el

@@ -674,13 +674,13 @@ of the result."
     (when (memq status '(exit signal))
       (catch 'return
 	(kill-buffer (process-get proc 'parse-buf))
-	(if (buffer-live-p buffer)
+	(when (buffer-live-p buffer)
 	  (with-current-buffer buffer
 	    (save-excursion
 	      (let ((inhibit-read-only t)
 		    (atbob (bobp)))
 		(goto-char (point-max))
-		  (if (eq status 'signal)
+		(when (eq status 'signal)
 		  (insert "Incomplete search results (search process was killed).\n"))
 		(when (eq status 'exit)
 		  (insert "End of search results.\n")
@@ -689,7 +689,7 @@ of the result."
 		  (when (or (= exit-status 20) (= exit-status 21))
 		    (kill-buffer)
 		    (throw 'return nil))
-		    (if (and atbob
+		  (when (and atbob
 			     (not (string= notmuch-search-target-thread "found")))
 		    (set 'never-found-target-thread t)))))
 	    (when (and never-found-target-thread
@@ -760,7 +760,7 @@ non-authors is found, assume that all of the authors match."
 	   (invisible-string "")
 	   (padding ""))
       ;; Truncate the author string to fit the specification.
-      (if (> (length formatted-authors)
+      (when (> (length formatted-authors)
 	       (length formatted-sample))
 	(let ((visible-length (- (length formatted-sample)
 				 (length "... "))))
@@ -1006,7 +1006,7 @@ the configured default sort order."
     (notmuch-tag-clear-cache)
     (let ((proc (get-buffer-process (current-buffer)))
 	  (inhibit-read-only t))
-      (if proc
+      (when proc
 	(error "notmuch search process already running for query `%s'" query))
       (erase-buffer)
       (goto-char (point-min))
@@ -1156,7 +1156,7 @@ beginning of the line."
 (provide 'notmuch)
 
 ;; After provide to avoid loops if notmuch was require'd via notmuch-init-file.
-(if init-file-user ; don't load init file if the -q option was used.
+(when init-file-user ; don't load init file if the -q option was used.
   (load notmuch-init-file t t nil t))
 
 ;;; notmuch.el ends here

test/test-lib.el

@@ -36,7 +36,7 @@
 
 ;; Work around a bug in emacs 23.1 and emacs 23.2 which prevents
 ;; noninteractive (kill-emacs) from emacsclient.
-(if (and (= emacs-major-version 23) (< emacs-minor-version 3))
+(when (and (= emacs-major-version 23) (< emacs-minor-version 3))
   (defadvice kill-emacs (before disable-yes-or-no-p activate)
     "Disable yes-or-no-p before executing kill-emacs"
     (defun yes-or-no-p (prompt) t)))
@@ -46,7 +46,7 @@
 ;; seems to be present in Emacs 23.1.
 ;; Running `list-processes' after `accept-process-output' seems to work
 ;; around this problem.
-(if (and (= emacs-major-version 23) (= emacs-minor-version 1))
+(when (and (= emacs-major-version 23) (= emacs-minor-version 1))
   (defadvice accept-process-output (after run-list-processes activate)
     "run list-processes after executing accept-process-output"
     (list-processes)))