X-Git-Url: https://git.notmuchmail.org/git?a=blobdiff_plain;f=emacs%2Fnotmuch-show.el;h=fdf4ab3c289b62f7b38e1bd619a767588041326e;hb=6cae6f32b197f863c2e53a8fc28d888998a4fb7c;hp=41f31c4653e3fed5c0b6a8351c4ecfa9e93ef26c;hpb=a4617f29ce81e7ae3e0cb747fdb9070f88407a28;p=notmuch

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 41f31c46..fdf4ab3c 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -1,4 +1,4 @@
-;;; notmuch-show.el --- displaying notmuch forests.
+;;; notmuch-show.el --- displaying notmuch forests  -*- lexical-binding: t -*-
 ;;
 ;; Copyright © Carl Worth
 ;; Copyright © David Edmondson
@@ -23,10 +23,6 @@
 
 ;;; Code:
 
-(eval-when-compile
-  (require 'cl-lib)
-  (require 'pcase))
-
 (require 'mm-view)
 (require 'message)
 (require 'mm-decode)
@@ -59,6 +55,12 @@
 (declare-function notmuch-read-query "notmuch" (prompt))
 (declare-function notmuch-draft-resume "notmuch-draft" (id))
 
+(defvar shr-blocked-images)
+(defvar gnus-blocked-images)
+(defvar shr-content-function)
+
+;;; Options
+
 (defcustom notmuch-message-headers '("Subject" "To" "Cc" "Date")
   "Headers that should be shown in a message, in this order.
 
@@ -162,23 +164,19 @@ indentation."
   :type '(choice (const nil) regexp)
   :group 'notmuch-show)
 
-(defvar notmuch-show-thread-id nil)
-(make-variable-buffer-local 'notmuch-show-thread-id)
+;;; Variables
 
-(defvar notmuch-show-parent-buffer nil)
-(make-variable-buffer-local 'notmuch-show-parent-buffer)
+(defvar-local notmuch-show-thread-id nil)
 
-(defvar notmuch-show-query-context nil)
-(make-variable-buffer-local 'notmuch-show-query-context)
+(defvar-local notmuch-show-parent-buffer nil)
 
-(defvar notmuch-show-process-crypto nil)
-(make-variable-buffer-local 'notmuch-show-process-crypto)
+(defvar-local notmuch-show-query-context nil)
 
-(defvar notmuch-show-elide-non-matching-messages nil)
-(make-variable-buffer-local 'notmuch-show-elide-non-matching-messages)
+(defvar-local notmuch-show-process-crypto nil)
 
-(defvar notmuch-show-indent-content t)
-(make-variable-buffer-local 'notmuch-show-indent-content)
+(defvar-local notmuch-show-elide-non-matching-messages nil)
+
+(defvar-local notmuch-show-indent-content t)
 
 (defvar notmuch-show-attachment-debug nil
   "If t log stdout and stderr from attachment handlers.
@@ -186,8 +184,9 @@ indentation."
 When set to nil (the default) stdout and stderr from attachment
 handlers is discarded. When set to t the stdout and stderr from
 each attachment handler is logged in buffers with names beginning
-\" *notmuch-part*\". This option requires emacs version at least
-24.3 to work.")
+\" *notmuch-part*\".")
+
+;;; Options
 
 (defcustom notmuch-show-stash-mlarchive-link-alist
   '(("Gmane" . "https://mid.gmane.org/")
@@ -267,12 +266,14 @@ position of the message in the thread."
   :type 'boolean
   :group 'notmuch-show)
 
+;;; Utilities
+
 (defmacro with-current-notmuch-show-message (&rest body)
   "Evaluate body with current buffer set to the text of current message."
   `(save-excursion
      (let ((id (notmuch-show-get-message-id)))
        (let ((buf (generate-new-buffer (concat "*notmuch-msg-" id "*"))))
-         (with-current-buffer buf
+	 (with-current-buffer buf
 	   (let ((coding-system-for-read 'no-conversion))
 	     (call-process notmuch-command nil t nil "show" "--format=raw" id))
 	   ,@body)
@@ -282,6 +283,8 @@ position of the message in the thread."
   "Enable Visual Line mode."
   (visual-line-mode t))
 
+;;; Commands
+
 ;; DEPRECATED in Notmuch 0.16 since we now have convenient part
 ;; commands.  We'll keep the command around for a version or two in
 ;; case people want to bind it themselves.
@@ -297,13 +300,12 @@ position of the message in the thread."
    ;;
    ;; Any MIME part not explicitly mentioned here will be handled by an
    ;; external viewer as configured in the various mailcap files.
-   (let ((mm-inline-media-tests '(
-				  ("text/.*" ignore identity)
-				  ("application/pgp-signature" ignore identity)
-				  ("multipart/alternative" ignore identity)
-				  ("multipart/mixed" ignore identity)
-				  ("multipart/related" ignore identity)
-				 )))
+   (let ((mm-inline-media-tests
+	  '(("text/.*" ignore identity)
+	    ("application/pgp-signature" ignore identity)
+	    ("multipart/alternative" ignore identity)
+	    ("multipart/mixed" ignore identity)
+	    ("multipart/related" ignore identity))))
      (mm-display-parts (mm-dissect-buffer)))))
 
 (defun notmuch-show-save-attachments ()
@@ -320,7 +322,6 @@ position of the message in the thread."
 
 FN is called with one argument, the message properties. It should
 operation on the contents of the current buffer."
-
   ;; Remake the header to ensure that all information is available.
   (let* ((to (notmuch-show-get-to))
 	 (cc (notmuch-show-get-cc))
@@ -329,11 +330,10 @@ operation on the contents of the current buffer."
 	 (date (notmuch-show-get-date))
 	 (tags (notmuch-show-get-tags))
 	 (depth (notmuch-show-get-depth))
-
 	 (header (concat
 		  "Subject: " subject "\n"
 		  "To: " to "\n"
-		  (if (not (string= cc ""))
+		  (if (not (string-empty-p cc))
 		      (concat "Cc: " cc "\n")
 		    "")
 		  "From: " from "\n"
@@ -349,10 +349,10 @@ operation on the contents of the current buffer."
 	 (indenting notmuch-show-indent-content))
     (with-temp-buffer
       (insert all)
-      (if indenting
-	  (indent-rigidly (point-min)
-			  (point-max)
-			  (- (* notmuch-show-indent-messages-width depth))))
+      (when indenting
+	(indent-rigidly (point-min)
+			(point-max)
+			(- (* notmuch-show-indent-messages-width depth))))
       ;; Remove the original header.
       (goto-char (point-min))
       (re-search-forward "^$" (point-max) nil)
@@ -365,6 +365,8 @@ operation on the contents of the current buffer."
   (interactive)
   (notmuch-show-with-message-as-text 'notmuch-print-message))
 
+;;; Headers
+
 (defun notmuch-show-fontify-header ()
   (let ((face (cond
 	       ((looking-at "[Tt]o:")
@@ -375,7 +377,6 @@ operation on the contents of the current buffer."
 		'message-header-subject)
 	       (t
 		'message-header-other))))
-
     (overlay-put (make-overlay (point) (re-search-forward ":"))
 		 'face 'message-header-name)
     (overlay-put (make-overlay (point) (re-search-forward ".*$"))
@@ -396,70 +397,62 @@ operation on the contents of the current buffer."
   "Update the displayed tags of the current message."
   (save-excursion
     (goto-char (notmuch-show-message-top))
-    (if (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
-	(let ((inhibit-read-only t))
-	  (replace-match (concat "("
-				 (notmuch-tag-format-tags
-				  tags
-				  (notmuch-show-get-prop :orig-tags))
-				 ")"))))))
+    (when (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
+      (let ((inhibit-read-only t))
+	(replace-match (concat "("
+			       (notmuch-tag-format-tags
+				tags
+				(notmuch-show-get-prop :orig-tags))
+			       ")"))))))
 
 (defun notmuch-clean-address (address)
   "Try to clean a single email ADDRESS for display. Return a cons
 cell of (AUTHOR_EMAIL AUTHOR_NAME). Return (ADDRESS nil) if
 parsing fails."
   (condition-case nil
-    (let (p-name p-address)
-      ;; It would be convenient to use `mail-header-parse-address',
-      ;; but that expects un-decoded mailbox parts, whereas our
-      ;; mailbox parts are already decoded (and hence may contain
-      ;; UTF-8). Given that notmuch should handle most of the awkward
-      ;; cases, some simple string deconstruction should be sufficient
-      ;; here.
-      (cond
-       ;; "User <user@dom.ain>" style.
-       ((string-match "\\(.*\\) <\\(.*\\)>" address)
-	(setq p-name (match-string 1 address)
-	      p-address (match-string 2 address)))
-
-       ;; "<user@dom.ain>" style.
-       ((string-match "<\\(.*\\)>" address)
-	(setq p-address (match-string 1 address)))
-
-       ;; Everything else.
-       (t
-	(setq p-address address)))
-
-      (when p-name
-	;; Remove elements of the mailbox part that are not relevant for
-	;; display, even if they are required during transport:
-	;;
-	;; Backslashes.
-	(setq p-name (replace-regexp-in-string "\\\\" "" p-name))
-
-	;; Outer single and double quotes, which might be nested.
-	(cl-loop with start-of-loop
-		 do (setq start-of-loop p-name)
-
-		 when (string-match "^\"\\(.*\\)\"$" p-name)
-		 do (setq p-name (match-string 1 p-name))
-
-		 when (string-match "^'\\(.*\\)'$" p-name)
-		 do (setq p-name (match-string 1 p-name))
-
-		 until (string= start-of-loop p-name)))
-
-      ;; If the address is 'foo@bar.com <foo@bar.com>' then show just
-      ;; 'foo@bar.com'.
-      (when (string= p-name p-address)
-	(setq p-name nil))
-
-      (cons p-address p-name))
+      (let (p-name p-address)
+	;; It would be convenient to use `mail-header-parse-address',
+	;; but that expects un-decoded mailbox parts, whereas our
+	;; mailbox parts are already decoded (and hence may contain
+	;; UTF-8). Given that notmuch should handle most of the awkward
+	;; cases, some simple string deconstruction should be sufficient
+	;; here.
+	(cond
+	 ;; "User <user@dom.ain>" style.
+	 ((string-match "\\(.*\\) <\\(.*\\)>" address)
+	  (setq p-name (match-string 1 address))
+	  (setq p-address (match-string 2 address)))
+
+	 ;; "<user@dom.ain>" style.
+	 ((string-match "<\\(.*\\)>" address)
+	  (setq p-address (match-string 1 address)))
+	 ;; Everything else.
+	 (t
+	  (setq p-address address)))
+	(when p-name
+	  ;; Remove elements of the mailbox part that are not relevant for
+	  ;; display, even if they are required during transport:
+	  ;;
+	  ;; Backslashes.
+	  (setq p-name (replace-regexp-in-string "\\\\" "" p-name))
+	  ;; Outer single and double quotes, which might be nested.
+	  (cl-loop with start-of-loop
+		   do   (setq start-of-loop p-name)
+		   when (string-match "^\"\\(.*\\)\"$" p-name)
+		   do   (setq p-name (match-string 1 p-name))
+		   when (string-match "^'\\(.*\\)'$" p-name)
+		   do   (setq p-name (match-string 1 p-name))
+		   until (string= start-of-loop p-name)))
+	;; If the address is 'foo@bar.com <foo@bar.com>' then show just
+	;; 'foo@bar.com'.
+	(when (string= p-name p-address)
+	  (setq p-name nil))
+	(cons p-address p-name))
     (error (cons address nil))))
 
 (defun notmuch-show-clean-address (address)
-  "Try to clean a single email ADDRESS for display.  Return
-unchanged ADDRESS if parsing fails."
+  "Try to clean a single email ADDRESS for display.
+Return unchanged ADDRESS if parsing fails."
   (let* ((clean-address (notmuch-clean-address address))
 	 (p-address (car clean-address))
 	 (p-name (cdr clean-address)))
@@ -480,7 +473,10 @@ message at DEPTH in the current thread."
       ;; invisible U+200E LEFT-TO-RIGHT MARK character which forces
       ;; the header paragraph as left-to-right text.
       (insert (propertize (string ?\x200e) 'invisible t)))
-    (insert (notmuch-show-spaces-n (* notmuch-show-indent-messages-width depth))
+    (insert (if notmuch-show-indent-content
+		(notmuch-show-spaces-n (* notmuch-show-indent-messages-width
+					  depth))
+	      "")
 	    from
 	    " ("
 	    date
@@ -500,39 +496,36 @@ 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
-		       (not (string-equal "" header-value)))
-		  (notmuch-show-insert-header header header-value))))
+	      (when (and header-value
+			 (not (string-equal "" header-value)))
+		(notmuch-show-insert-header header header-value))))
 	  notmuch-message-headers)
     (save-excursion
       (save-restriction
 	(narrow-to-region start (point-max))
 	(run-hooks 'notmuch-show-markup-headers-hook)))))
 
+;;; Parts
+
 (define-button-type 'notmuch-show-part-button-type
   'action 'notmuch-show-part-button-default
   'follow-link t
   'face 'message-mml
   :supertype 'notmuch-button-type)
 
-(defun notmuch-show-insert-part-header (nth content-type declared-type
+(defun notmuch-show-insert-part-header (_nth content-type declared-type
 					    &optional name comment)
-  (let ((button)
-	(base-label (concat (when name (concat name ": "))
+  (let ((base-label (concat (and name (concat name ": "))
 			    declared-type
-			    (unless (string-equal declared-type content-type)
-			      (concat " (as " content-type ")"))
+			    (and (not (string-equal declared-type content-type))
+				 (concat " (as " content-type ")"))
 			    comment)))
-
-    (setq button
-	  (insert-button
-	   (concat "[ " base-label " ]")
-	   :base-label base-label
-	   :type 'notmuch-show-part-button-type
-	   :notmuch-part-hidden nil))
-    (insert "\n")
-    ;; return button
-    button))
+    (prog1 (insert-button
+	    (concat "[ " base-label " ]")
+	    :base-label base-label
+	    :type 'notmuch-show-part-button-type
+	    :notmuch-part-hidden nil)
+      (insert "\n"))))
 
 (defun notmuch-show-toggle-part-invisibility (&optional button)
   (interactive)
@@ -569,7 +562,7 @@ message at DEPTH in the current thread."
 	      (overlay-put overlay 'invisible (not show))
 	      t)))))))
 
-;; Part content ID handling
+;;; Part content ID handling
 
 (defvar notmuch-show--cids nil
   "Alist from raw content ID to (MSG PART).")
@@ -588,12 +581,13 @@ message at DEPTH in the current thread."
       ;; alternative (even if we can't render it).
       (push (list content-id msg part) notmuch-show--cids)))
   ;; Recurse on sub-parts
-  (let ((ctype (notmuch-split-content-type
-		(downcase (plist-get part :content-type)))))
-    (cond ((equal (car ctype) "multipart")
+  (pcase-let ((`(,content ,type)
+	       (split-string (downcase (plist-get part :content-type)) "/")))
+    (cond ((equal content "multipart")
 	   (mapc (apply-partially #'notmuch-show--register-cids msg)
 		 (plist-get part :content)))
-	  ((equal ctype '("message" "rfc822"))
+	  ((and (equal content "message")
+		(equal type "rfc822"))
 	   (notmuch-show--register-cids
 	    msg
 	    (car (plist-get (car (plist-get part :content)) :body)))))))
@@ -619,14 +613,14 @@ 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)
-      (push (cons 'notmuch-show-mode #'notmuch-show--cid-w3m-retrieve)
-	    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))
   (setq mm-html-inhibit-images nil))
 
 (defvar w3m-current-buffer) ;; From `w3m.el'.
-(defun notmuch-show--cid-w3m-retrieve (url &rest args)
+(defun notmuch-show--cid-w3m-retrieve (url &rest _args)
   ;; url includes the cid: prefix and is URL encoded (see RFC 2392).
   (let* ((cid (url-unhex-string (substring url 4)))
 	 (content-and-type
@@ -642,7 +636,7 @@ will return nil if the CID is unknown or cannot be retrieved."
   (mapcar (lambda (inner-part) (plist-get inner-part :content-type))
 	  (plist-get part :content)))
 
-(defun notmuch-show-insert-part-multipart/alternative (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-multipart/alternative (msg part _content-type _nth depth _button)
   (let ((chosen-type (car (notmuch-multipart/alternative-choose
 			   msg (notmuch-show-multipart/*-to-list part))))
 	(inner-parts (plist-get part :content))
@@ -652,8 +646,8 @@ will return nil if the CID is unknown or cannot be retrieved."
     ;; should be chosen if there are more than one that match?
     (mapc (lambda (inner-part)
 	    (let* ((inner-type (plist-get inner-part :content-type))
-		  (hide (not (or notmuch-show-all-multipart/alternative-parts
-			   (string= chosen-type inner-type)))))
+		   (hide (not (or notmuch-show-all-multipart/alternative-parts
+				  (string= chosen-type inner-type)))))
 	      (notmuch-show-insert-bodypart msg inner-part depth hide)))
 	  inner-parts)
 
@@ -661,99 +655,85 @@ will return nil if the CID is unknown or cannot be retrieved."
       (indent-rigidly start (point) 1)))
   t)
 
-(defun notmuch-show-insert-part-multipart/related (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-multipart/related (msg part _content-type _nth depth _button)
   (let ((inner-parts (plist-get part :content))
 	(start (point)))
-
     ;; Render the primary part.  FIXME: Support RFC 2387 Start header.
     (notmuch-show-insert-bodypart msg (car inner-parts) depth)
     ;; Add hidden buttons for the rest
     (mapc (lambda (inner-part)
 	    (notmuch-show-insert-bodypart msg inner-part depth t))
 	  (cdr inner-parts))
-
     (when notmuch-show-indent-multipart
       (indent-rigidly start (point) 1)))
   t)
 
-(defun notmuch-show-insert-part-multipart/signed (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-multipart/signed (msg part _content-type _nth depth button)
   (when button
     (button-put button 'face 'notmuch-crypto-part-header))
-
   ;; Insert a button detailing the signature status.
   (notmuch-crypto-insert-sigstatus-button (car (plist-get part :sigstatus))
 					  (notmuch-show-get-header :From msg))
-
   (let ((inner-parts (plist-get part :content))
 	(start (point)))
     ;; Show all of the parts.
     (mapc (lambda (inner-part)
 	    (notmuch-show-insert-bodypart msg inner-part depth))
 	  inner-parts)
-
     (when notmuch-show-indent-multipart
       (indent-rigidly start (point) 1)))
   t)
 
-(defun notmuch-show-insert-part-multipart/encrypted (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-multipart/encrypted (msg part _content-type _nth depth button)
   (when button
     (button-put button 'face 'notmuch-crypto-part-header))
-
   ;; Insert a button detailing the encryption status.
   (notmuch-crypto-insert-encstatus-button (car (plist-get part :encstatus)))
-
   ;; Insert a button detailing the signature status.
   (notmuch-crypto-insert-sigstatus-button (car (plist-get part :sigstatus))
 					  (notmuch-show-get-header :From msg))
-
   (let ((inner-parts (plist-get part :content))
 	(start (point)))
     ;; Show all of the parts.
     (mapc (lambda (inner-part)
 	    (notmuch-show-insert-bodypart msg inner-part depth))
 	  inner-parts)
-
     (when notmuch-show-indent-multipart
       (indent-rigidly start (point) 1)))
   t)
 
-(defun notmuch-show-insert-part-application/pgp-encrypted (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-application/pgp-encrypted (_msg _part _content-type _nth _depth _button)
   t)
 
-(defun notmuch-show-insert-part-multipart/* (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-multipart/* (msg part _content-type _nth depth _button)
   (let ((inner-parts (plist-get part :content))
 	(start (point)))
     ;; Show all of the parts.
     (mapc (lambda (inner-part)
 	    (notmuch-show-insert-bodypart msg inner-part depth))
 	  inner-parts)
-
     (when notmuch-show-indent-multipart
       (indent-rigidly start (point) 1)))
   t)
 
-(defun notmuch-show-insert-part-message/rfc822 (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-message/rfc822 (msg part _content-type _nth depth _button)
   (let* ((message (car (plist-get part :content)))
 	 (body (car (plist-get message :body)))
 	 (start (point)))
-
     ;; Override `notmuch-message-headers' to force `From' to be
     ;; displayed.
     (let ((notmuch-message-headers '("From" "Subject" "To" "Cc" "Date")))
       (notmuch-show-insert-headers (plist-get message :headers)))
-
     ;; Blank line after headers to be compatible with the normal
     ;; message display.
     (insert "\n")
-
     ;; Show the body
     (notmuch-show-insert-bodypart msg body depth)
-
     (when notmuch-show-indent-multipart
       (indent-rigidly start (point) 1)))
   t)
 
-(defun notmuch-show-insert-part-text/plain (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-text/plain (msg part _content-type _nth depth button)
   ;; For backward compatibility we want to apply the text/plain hook
   ;; to the whole of the part including the part button if there is
   ;; one.
@@ -767,7 +747,7 @@ will return nil if the CID is unknown or cannot be retrieved."
 	(run-hook-with-args 'notmuch-show-insert-text/plain-hook msg depth))))
   t)
 
-(defun notmuch-show-insert-part-text/calendar (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-text/calendar (msg part _content-type _nth _depth _button)
   (insert (with-temp-buffer
 	    (insert (notmuch-get-bodypart-text msg part notmuch-show-process-crypto))
 	    ;; notmuch-get-bodypart-text does no newline conversion.
@@ -791,48 +771,44 @@ will return nil if the CID is unknown or cannot be retrieved."
   t)
 
 ;; For backwards compatibility.
-(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")
-    ;; https://bugs.gnu.org/28350
-    ;;
-    ;; For newer emacs, we fall back to notmuch-show-insert-part-*/*
-    ;; (see notmuch-show-handlers-for)
-    (defun notmuch-show-insert-part-text/enriched
-	(msg part content-type nth depth button)
-      ;; By requiring enriched below, we ensure that the function
-      ;; enriched-decode-display-prop is defined before it will be
-      ;; shadowed by the letf below. Otherwise the version in
-      ;; enriched.el may be loaded a bit later and used instead (for
-      ;; the first time).
-      (require 'enriched)
-      (cl-letf (((symbol-function 'enriched-decode-display-prop)
-		 (lambda (start end &optional param) (list start end))))
-	(notmuch-show-insert-part-*/* msg part content-type nth depth button))))
+(defun notmuch-show-insert-part-text/x-vcalendar (msg part _content-type _nth depth _button)
+  (notmuch-show-insert-part-text/calendar msg part nil nil depth nil))
+
+(when (version< emacs-version "25.3")
+  ;; https://bugs.gnu.org/28350
+  ;;
+  ;; For newer emacs, we fall back to notmuch-show-insert-part-*/*
+  ;; (see notmuch-show-handlers-for)
+  (defun notmuch-show-insert-part-text/enriched
+      (msg part content-type nth depth button)
+    ;; By requiring enriched below, we ensure that the function
+    ;; enriched-decode-display-prop is defined before it will be
+    ;; shadowed by the letf below. Otherwise the version in
+    ;; enriched.el may be loaded a bit later and used instead (for
+    ;; the first time).
+    (require 'enriched)
+    (cl-letf (((symbol-function 'enriched-decode-display-prop)
+	       (lambda (start end &optional _param) (list start end))))
+      (notmuch-show-insert-part-*/* msg part content-type nth depth button))))
 
 (defun notmuch-show-get-mime-type-of-application/octet-stream (part)
   ;; If we can deduce a MIME type from the filename of the attachment,
   ;; we return that.
-  (if (plist-get part :filename)
-      (let ((extension (file-name-extension (plist-get part :filename)))
-	    mime-type)
-	(if extension
-	    (progn
-	      (mailcap-parse-mimetypes)
-	      (setq mime-type (mailcap-extension-to-mime extension))
-	      (if (and mime-type
-		       (not (string-equal mime-type "application/octet-stream")))
-		  mime-type
-		nil))
-	  nil))))
+  (and (plist-get part :filename)
+       (let ((extension (file-name-extension (plist-get part :filename))))
+	 (and extension
+	      (progn
+		(mailcap-parse-mimetypes)
+		(let ((mime-type (mailcap-extension-to-mime extension)))
+		  (and mime-type
+		       (not (string-equal mime-type "application/octet-stream"))
+		       mime-type)))))))
 
 (defun notmuch-show-insert-part-text/html (msg part content-type nth depth button)
   (if (eq mm-text-html-renderer 'shr)
       ;; It's easier to drive shr ourselves than to work around the
       ;; goofy things `mm-shr' does (like irreversibly taking over
       ;; content ID handling).
-
       ;; FIXME: If we block an image, offer a button to load external
       ;; images.
       (let ((shr-blocked-images notmuch-show-text/html-blocked-images))
@@ -849,7 +825,8 @@ will return nil if the CID is unknown or cannot be retrieved."
 	  (gnus-blocked-images notmuch-show-text/html-blocked-images))
       (notmuch-show-insert-part-*/* msg part content-type nth depth button))))
 
-;; These functions are used by notmuch-show--insert-part-text/html-shr
+;;; Functions used by notmuch-show--insert-part-text/html-shr
+
 (declare-function libxml-parse-html-region "xml.c")
 (declare-function shr-insert-document "shr")
 
@@ -869,29 +846,28 @@ will return nil if the CID is unknown or cannot be retrieved."
     (shr-insert-document dom)
     t))
 
-(defun notmuch-show-insert-part-*/* (msg part content-type nth depth button)
+(defun notmuch-show-insert-part-*/* (msg part content-type _nth _depth _button)
   ;; This handler _must_ succeed - it is the handler of last resort.
   (notmuch-mm-display-part-inline msg part content-type notmuch-show-process-crypto)
   t)
 
-;; Functions for determining how to handle MIME parts.
+;;; Functions for determining how to handle MIME parts.
 
 (defun notmuch-show-handlers-for (content-type)
   "Return a list of content handlers for a part of type CONTENT-TYPE."
   (let (result)
     (mapc (lambda (func)
-	    (if (functionp func)
-		(push func result)))
+	    (when (functionp func)
+	      (push func result)))
 	  ;; Reverse order of prefrence.
 	  (list (intern (concat "notmuch-show-insert-part-*/*"))
-		(intern (concat
-			 "notmuch-show-insert-part-"
-			 (car (notmuch-split-content-type content-type))
-			 "/*"))
+		(intern (concat "notmuch-show-insert-part-"
+				(car (split-string content-type "/"))
+				"/*"))
 		(intern (concat "notmuch-show-insert-part-" content-type))))
     result))
 
-;; 
+;;; Parts
 
 (defun notmuch-show-insert-bodypart-internal (msg part content-type nth depth button)
   ;; Run the handlers until one of them succeeds.
@@ -908,7 +884,6 @@ will return nil if the CID is unknown or cannot be retrieved."
 
 (defun notmuch-show-create-part-overlays (button beg end)
   "Add an overlay to the part between BEG and END."
-
   ;; If there is no button (i.e., the part is text/plain and the first
   ;; part) or if the part has no content then we don't make the part
   ;; toggleable.
@@ -919,7 +894,6 @@ will return nil if the CID is unknown or cannot be retrieved."
 
 (defun notmuch-show-record-part-information (part beg end)
   "Store PART as a text property from BEG to END."
-
   ;; Record part information.  Since we already inserted subparts,
   ;; don't override existing :notmuch-part properties.
   (notmuch-map-text-property beg end :notmuch-part
@@ -992,13 +966,13 @@ The function should take two parameters, PART and HIDE, and
 should return non-NIL if a header button should be inserted for
 this part.")
 
-(defun notmuch-show-insert-header-p (part hide)
+(defun notmuch-show-insert-header-p (part _hide)
   ;; Show all part buttons except for the first part if it is text/plain.
   (let ((mime-type (notmuch-show-mime-type part)))
     (not (and (string= mime-type "text/plain")
 	      (<= (plist-get part :id) 1)))))
 
-(defun notmuch-show-reply-insert-header-p-never (part hide)
+(defun notmuch-show-reply-insert-header-p-never (_part _hide)
   nil)
 
 (defun notmuch-show-reply-insert-header-p-trimmed (part hide)
@@ -1017,7 +991,6 @@ this part.")
 HIDE determines whether to show or hide the part and the button
 as follows: If HIDE is nil, show the part and the button. If HIDE
 is t, hide the part initially and show the button."
-
   (let* ((content-type (downcase (plist-get part :content-type)))
 	 (mime-type (notmuch-show-mime-type part))
 	 (nth (plist-get part :id))
@@ -1028,24 +1001,22 @@ is t, hide the part initially and show the button."
 	 (beg (point))
 	 ;; This default header-p function omits the part button for
 	 ;; the first (or only) part if this is text/plain.
-	 (button (when (funcall notmuch-show-insert-header-p-function part hide)
-		   (notmuch-show-insert-part-header nth mime-type content-type
-						    (plist-get part :filename))))
+	 (button (and (funcall notmuch-show-insert-header-p-function part hide)
+		      (notmuch-show-insert-part-header
+		       nth mime-type content-type
+		       (plist-get part :filename))))
 	 ;; Hide the part initially if HIDE is t, or if it is too long
 	 ;; and we have a button to allow toggling.
 	 (show-part (not (or (equal hide t)
 			     (and long button))))
 	 (content-beg (point)))
-
     ;; Store the computed mime-type for later use (e.g. by attachment handlers).
     (plist-put part :computed-type mime-type)
-
     (if show-part
-        (notmuch-show-insert-bodypart-internal msg part mime-type nth depth button)
+	(notmuch-show-insert-bodypart-internal msg part mime-type nth depth button)
       (when button
 	(button-put button :notmuch-lazy-part
 		    (list msg part mime-type nth depth button))))
-
     ;; Some of the body part handlers leave point somewhere up in the
     ;; part, so we make sure that we're down at the end.
     (goto-char (point-max))
@@ -1062,12 +1033,10 @@ is t, hide the part initially and show the button."
 
 (defun notmuch-show-insert-body (msg body depth)
   "Insert the body BODY at depth DEPTH in the current thread."
-
   ;; Register all content IDs for this message.  According to RFC
   ;; 2392, content IDs are *global*, but it's okay if an MUA treats
   ;; them as only global within a message.
   (notmuch-show--register-cids msg (car body))
-
   (mapc (lambda (part) (notmuch-show-insert-bodypart msg part depth)) body))
 
 (defun notmuch-show-make-symbol (type)
@@ -1088,18 +1057,13 @@ is t, hide the part initially and show the button."
 	 content-start content-end
 	 headers-start headers-end
 	 (bare-subject (notmuch-show-strip-re (plist-get headers :Subject))))
-
     (setq message-start (point-marker))
-
     (notmuch-show-insert-headerline headers
-				    (or (if notmuch-show-relative-dates
-					    (plist-get msg :date_relative)
-					  nil)
+				    (or (and notmuch-show-relative-dates
+					     (plist-get msg :date_relative))
 					(plist-get headers :Date))
 				    (plist-get msg :tags) depth)
-
     (setq content-start (point-marker))
-
     ;; Set `headers-start' to point after the 'Subject:' header to be
     ;; compatible with the existing implementation. This just sets it
     ;; to after the first header.
@@ -1109,14 +1073,11 @@ is t, hide the part initially and show the button."
       ;; If the subject of this message is the same as that of the
       ;; previous message, don't display it when this message is
       ;; collapsed.
-      (when (not (string= notmuch-show-previous-subject
-			  bare-subject))
+      (unless (string= notmuch-show-previous-subject bare-subject)
 	(forward-line 1))
       (setq headers-start (point-marker)))
     (setq headers-end (point-marker))
-
     (setq notmuch-show-previous-subject bare-subject)
-
     ;; A blank line between the headers and the body.
     (insert "\n")
     (notmuch-show-insert-body msg (plist-get msg :body)
@@ -1125,41 +1086,35 @@ is t, hide the part initially and show the button."
     (unless (bolp)
       (insert "\n"))
     (setq content-end (point-marker))
-
     ;; Indent according to the depth in the thread.
-    (if notmuch-show-indent-content
-	(indent-rigidly content-start
-			content-end
-			(* notmuch-show-indent-messages-width depth)))
-
+    (when notmuch-show-indent-content
+      (indent-rigidly content-start
+		      content-end
+		      (* notmuch-show-indent-messages-width depth)))
     (setq message-end (point-max-marker))
-
     ;; Save the extents of this message over the whole text of the
     ;; message.
     (put-text-property message-start message-end
 		       :notmuch-message-extent
 		       (cons message-start message-end))
-
     ;; Create overlays used to control visibility
     (plist-put msg :headers-overlay (make-overlay headers-start headers-end))
     (plist-put msg :message-overlay (make-overlay headers-start content-end))
-
     (plist-put msg :depth depth)
-
     ;; Save the properties for this message. Currently this saves the
     ;; entire message (augmented it with other stuff), which seems
     ;; like overkill. We might save a reduced subset (for example, not
     ;; the content).
     (notmuch-show-set-message-properties msg)
-
     ;; Set header visibility.
     (notmuch-show-headers-visible msg notmuch-message-headers-visible)
-
     ;; Message visibility depends on whether it matched the search
     ;; criteria.
     (notmuch-show-message-visible msg (and (plist-get msg :match)
 					   (not (plist-get msg :excluded))))))
 
+;;; Toggle commands
+
 (defun notmuch-show-toggle-process-crypto ()
   "Toggle the processing of cryptographic MIME parts."
   (interactive)
@@ -1188,6 +1143,8 @@ is t, hide the part initially and show the button."
 	     "Content is not indented."))
   (notmuch-show-refresh-view))
 
+;;; Main insert functions
+
 (defun notmuch-show-insert-tree (tree depth)
   "Insert the message tree TREE at depth DEPTH in the current thread."
   (let ((msg (car tree))
@@ -1205,6 +1162,8 @@ is t, hide the part initially and show the button."
   "Insert the forest of threads FOREST."
   (mapc (lambda (thread) (notmuch-show-insert-thread thread 0)) forest))
 
+;;; Link buttons
+
 (defvar notmuch-id-regexp
   (concat
    ;; Match the id: prefix only if it begins a word (to disallow, for
@@ -1265,6 +1224,8 @@ buttons for a corresponding notmuch search."
 			  'help-echo "Mouse-1, RET: search for this message"
 			  'face goto-address-mail-face)))))
 
+;;; Show command
+
 ;;;###autoload
 (defun notmuch-show (thread-id &optional elide-toggle parent-buffer query-context buffer-name)
   "Run \"notmuch show\" with the given thread ID and display results.
@@ -1299,38 +1260,33 @@ matched."
 		    (eval (car (get 'mm-inline-override-types 'standard-value))))
 	     (cons "application/*" mm-inline-override-types)
 	   mm-inline-override-types)))
-    (switch-to-buffer (get-buffer-create buffer-name))
+    (pop-to-buffer-same-window (get-buffer-create buffer-name))
     ;; No need to track undo information for this buffer.
     (setq buffer-undo-list t)
-
     (notmuch-show-mode)
-
     ;; Set various buffer local variables to their appropriate initial
     ;; state. Do this after enabling `notmuch-show-mode' so that they
     ;; aren't wiped out.
-    (setq notmuch-show-thread-id thread-id
-	  notmuch-show-parent-buffer parent-buffer
-	  notmuch-show-query-context (if (or (string= query-context "")
-					     (string= query-context "*"))
-					 nil query-context)
-
-	  notmuch-show-process-crypto notmuch-crypto-process-mime
-	  ;; If `elide-toggle', invert the default value.
-	  notmuch-show-elide-non-matching-messages
+    (setq notmuch-show-thread-id thread-id)
+    (setq notmuch-show-parent-buffer parent-buffer)
+    (setq notmuch-show-query-context
+	  (if (or (string= query-context "")
+		  (string= query-context "*"))
+	      nil
+	    query-context))
+    (setq notmuch-show-process-crypto notmuch-crypto-process-mime)
+    ;; If `elide-toggle', invert the default value.
+    (setq notmuch-show-elide-non-matching-messages
 	  (if elide-toggle
 	      (not notmuch-show-only-matching-messages)
 	    notmuch-show-only-matching-messages))
-
     (add-hook 'post-command-hook #'notmuch-show-command-hook nil t)
     (jit-lock-register #'notmuch-show-buttonise-links)
-
     (notmuch-tag-clear-cache)
-
     (let ((inhibit-read-only t))
       (if (notmuch-show--build-buffer)
 	  ;; Messages were inserted into the buffer.
 	  (current-buffer)
-
 	;; No messages were inserted - presumably none matched the
 	;; query.
 	(kill-buffer (current-buffer))
@@ -1347,7 +1303,8 @@ 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)
@@ -1358,8 +1315,8 @@ first relevant message.
 
 If no messages match the query return NIL."
   (let* ((cli-args (cons "--exclude=false"
-			 (when notmuch-show-elide-non-matching-messages
-			   (list "--entire-thread=false"))))
+			 (and notmuch-show-elide-non-matching-messages
+			      (list "--entire-thread=false"))))
 	 (queries (notmuch-show--build-queries
 		   notmuch-show-thread-id notmuch-show-query-context))
 	 (forest nil)
@@ -1373,29 +1330,26 @@ If no messages match the query return NIL."
       (setq queries (cdr queries)))
     (when forest
       (notmuch-show-insert-forest forest)
-
       ;; Store the original tags for each message so that we can
       ;; display changes.
       (notmuch-show-mapc
        (lambda () (notmuch-show-set-prop :orig-tags (notmuch-show-get-tags))))
-
       ;; Set the header line to the subject of the first message.
       (setq header-line-format
 	    (replace-regexp-in-string "%" "%%"
 				      (notmuch-sanitize
 				       (notmuch-show-strip-re
 					(notmuch-show-get-subject)))))
-
       (run-hooks 'notmuch-show-hook)
-
       (if state
 	  (notmuch-show-apply-state state)
 	;; With no state to apply, just go to the first message.
 	(notmuch-show-goto-first-wanted-message)))
-
     ;; Report back to the caller whether any messages matched.
     forest))
 
+;;; Refresh command
+
 (defun notmuch-show-capture-state ()
   "Capture the state of the current buffer.
 
@@ -1437,14 +1391,12 @@ This includes:
  - moving to the correct current message in every displayed window."
   (let ((win-msg-alist (car state))
 	(open (cadr state)))
-
     ;; Open those that were open.
     (goto-char (point-min))
     (cl-loop do (notmuch-show-message-visible
 		 (notmuch-show-get-message-properties)
 		 (member (notmuch-show-get-message-id) open))
 	     until (not (notmuch-show-goto-message-next)))
-
     (dolist (win-msg-pair win-msg-alist)
       (with-selected-window (car win-msg-pair)
 	;; Go to the previously open message in this window
@@ -1466,13 +1418,14 @@ reset based on the original query."
     ;; manually.
     (remove-overlays)
     (erase-buffer)
-
     (unless (notmuch-show--build-buffer state)
       ;; No messages were inserted.
       (kill-buffer (current-buffer))
       (ding)
       (message "Refreshing the buffer resulted in no messages!"))))
 
+;;; Keymaps
+
 (defvar notmuch-show-stash-map
   (let ((map (make-sparse-keymap)))
     (define-key map "c" 'notmuch-show-stash-cc)
@@ -1552,7 +1505,8 @@ reset based on the original query."
     (define-key map "B" 'notmuch-show-browse-urls)
     map)
   "Keymap for \"notmuch show\" buffers.")
-(fset 'notmuch-show-mode-map notmuch-show-mode-map)
+
+;;; Mode
 
 (define-derived-mode notmuch-show-mode fundamental-mode "notmuch-show"
   "Major mode for viewing a thread with notmuch.
@@ -1583,12 +1537,14 @@ All currently available key bindings:
 
 \\{notmuch-show-mode-map}"
   (setq notmuch-buffer-refresh-function #'notmuch-show-refresh-view)
-  (setq buffer-read-only t
-	truncate-lines t)
+  (setq buffer-read-only t)
+  (setq truncate-lines t)
   (setq imenu-prev-index-position-function
-        #'notmuch-show-imenu-prev-index-position-function)
+	#'notmuch-show-imenu-prev-index-position-function)
   (setq imenu-extract-index-name-function
-        #'notmuch-show-imenu-extract-index-name-function))
+	#'notmuch-show-imenu-extract-index-name-function))
+
+;;; Tree commands
 
 (defun notmuch-tree-from-show-current-query ()
   "Call notmuch tree with the current query."
@@ -1604,17 +1560,14 @@ All currently available key bindings:
 		      notmuch-show-query-context
 		      (notmuch-show-get-message-id)))
 
+;;; Movement related functions.
+
 (defun notmuch-show-move-to-message-top ()
   (goto-char (notmuch-show-message-top)))
 
 (defun notmuch-show-move-to-message-bottom ()
   (goto-char (notmuch-show-message-bottom)))
 
-(defun notmuch-show-message-adjust ()
-  (recenter 0))
-
-;; Movement related functions.
-
 ;; There's some strangeness here where a text property applied to a
 ;; region a->b is not found when point is at b. We walk backwards
 ;; until finding the property.
@@ -1658,8 +1611,7 @@ effects."
     (cl-loop do (funcall function)
 	     while (notmuch-show-goto-message-next))))
 
-;; Functions relating to the visibility of messages and their
-;; components.
+;;; Functions relating to the visibility of messages and their components.
 
 (defun notmuch-show-message-visible (props visible-p)
   (overlay-put (plist-get props :message-overlay) 'invisible (not visible-p))
@@ -1669,8 +1621,7 @@ effects."
   (overlay-put (plist-get props :headers-overlay) 'invisible (not visible-p))
   (notmuch-show-set-prop :headers-visible visible-p props))
 
-;; Functions for setting and getting attributes of the current
-;; message.
+;;; Functions for setting and getting attributes of the current message.
 
 (defun notmuch-show-set-message-properties (props)
   (save-excursion
@@ -1711,13 +1662,13 @@ It gets property PROP from PROPS or, if PROPS is nil, the current
 message in either tree or show. This means that several utility
 functions in notmuch-show can be used directly by notmuch-tree as
 they just need the correct message properties."
-  (let ((props (or props
-		   (cond ((eq major-mode 'notmuch-show-mode)
-			  (notmuch-show-get-message-properties))
-			 ((eq major-mode 'notmuch-tree-mode)
-			  (notmuch-tree-get-message-properties))
-			 (t nil)))))
-    (plist-get props prop)))
+  (plist-get (or props
+		 (cond ((eq major-mode 'notmuch-show-mode)
+			(notmuch-show-get-message-properties))
+		       ((eq major-mode 'notmuch-tree-mode)
+			(notmuch-tree-get-message-properties))
+		       (t nil)))
+	     prop))
 
 (defun notmuch-show-get-message-id (&optional bare)
   "Return an id: query for the Message-Id of the current message.
@@ -1804,15 +1755,15 @@ marked as unread, i.e. the tag changes in
     (apply 'notmuch-show-tag-message
 	   (notmuch-tag-change-list notmuch-show-mark-read-tags unread))))
 
-(defun notmuch-show-seen-current-message (start end)
+(defun notmuch-show-seen-current-message (_start _end)
   "Mark the current message read if it is open.
 
 We only mark it read once: if it is changed back then that is a
 user decision and we should not override it."
   (when (and (notmuch-show-message-visible-p)
 	     (not (notmuch-show-get-prop :seen)))
-	(notmuch-show-mark-read)
-	(notmuch-show-set-prop :seen t)))
+    (notmuch-show-mark-read)
+    (notmuch-show-set-prop :seen t)))
 
 (defvar notmuch-show--seen-has-errored nil)
 (make-variable-buffer-local 'notmuch-show--seen-has-errored)
@@ -1822,11 +1773,11 @@ user decision and we should not override it."
     ;; We need to redisplay to get window-start and window-end correct.
     (redisplay)
     (save-excursion
-      (condition-case err
+      (condition-case nil
 	  (funcall notmuch-show-mark-read-function (window-start) (window-end))
 	((debug error)
 	 (unless notmuch-show--seen-has-errored
-	   (setq notmuch-show--seen-has-errored 't)
+	   (setq notmuch-show--seen-has-errored t)
 	   (setq header-line-format
 		 (concat header-line-format
 			 (propertize
@@ -1839,12 +1790,11 @@ user decision and we should not override it."
 Reshows the current thread with matches defined by the new query-string."
   (interactive (list (notmuch-read-query "Filter thread: ")))
   (let ((msg-id (notmuch-show-get-message-id)))
-    (setq notmuch-show-query-context (if (string= query "") nil query))
+    (setq notmuch-show-query-context (if (string-empty-p query) nil query))
     (notmuch-show-refresh-view t)
     (notmuch-show-goto-message msg-id)))
 
-;; Functions for getting attributes of several messages in the current
-;; thread.
+;;; Functions for getting attributes of several messages in the current thread.
 
 (defun notmuch-show-get-message-ids-for-open-messages ()
   "Return a list of all id: queries for open messages in the current thread."
@@ -1852,15 +1802,13 @@ 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)
-	    (setq message-ids
-		  (append message-ids (list (notmuch-show-get-message-id)))))
-	(setq done (not (notmuch-show-goto-message-next)))
-	)
-      message-ids
-      )))
+	(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))))
+      message-ids)))
 
-;; Commands typically bound to keys.
+;;; Commands typically bound to keys.
 
 (defun notmuch-show-advance ()
   "Advance through thread.
@@ -1887,16 +1835,13 @@ current window), advance to the next open message."
 	   (> visible-end-of-this-message (window-end)))
       ;; The bottom of this message is not visible - scroll.
       (scroll-up nil))
-
      ((not (= end-of-this-message (point-max)))
       ;; This is not the last message - move to the next visible one.
       (notmuch-show-next-open-message))
-
      ((not (= (point) (point-max)))
       ;; This is the last message, but the cursor is not at the end of
       ;; the buffer. Move it there.
       (goto-char (point-max)))
-
      (t
       ;; This is the last message - change the return value
       (setq ret t)))
@@ -1914,8 +1859,8 @@ archives the entire current thread, (apply changes in
 thread from the search from which this thread was originally
 shown."
   (interactive)
-  (if (notmuch-show-advance)
-      (notmuch-show-archive-thread-then-next)))
+  (when (notmuch-show-advance)
+    (notmuch-show-archive-thread-then-next)))
 
 (defun notmuch-show-rewind ()
   "Backup through the thread (reverse scrolling compared to \
@@ -1934,9 +1879,9 @@ any effects from previous calls to
   (let ((start-of-message (notmuch-show-message-top))
 	(start-of-window (window-start)))
     (cond
-      ;; Either this message is properly aligned with the start of the
-      ;; window or the start of this message is not visible on the
-      ;; screen - scroll.
+     ;; Either this message is properly aligned with the start of the
+     ;; window or the start of this message is not visible on the
+     ;; screen - scroll.
      ((or (= start-of-message start-of-window)
 	  (< start-of-message start-of-window))
       (scroll-down)
@@ -1991,6 +1936,9 @@ any effects from previous calls to
     (message-resend addresses)
     (notmuch-bury-or-kill-this-buffer)))
 
+(defun notmuch-show-message-adjust ()
+  (recenter 0))
+
 (defun notmuch-show-next-message (&optional pop-at-end)
   "Show the next message.
 
@@ -2073,7 +2021,7 @@ to show, nil otherwise."
   (let* ((id (notmuch-show-get-message-id))
 	 (buf (get-buffer-create (concat "*notmuch-raw-" id "*")))
 	 (inhibit-read-only t))
-    (switch-to-buffer buf)
+    (pop-to-buffer-same-window buf)
     (erase-buffer)
     (let ((coding-system-for-read 'no-conversion))
       (call-process notmuch-command nil t nil "show" "--format=raw" id))
@@ -2132,7 +2080,7 @@ message."
 	  (set-buffer-modified-p nil)
 	  (setq buffer-read-only t)
 	  (unless (zerop exit-code)
-	    (switch-to-buffer-other-window buf)
+	    (pop-to-buffer buf)
 	    (message (format "Command '%s' exited abnormally with code %d"
 			     shell-command exit-code))))))))
 
@@ -2421,7 +2369,9 @@ the user (see `notmuch-show-stash-mlarchive-link-alist')."
   (browse-url (current-kill 0 t)))
 
 (defun notmuch-show-stash-git-helper (addresses prefix)
-  "Escape, trim, quote, and add PREFIX to each address in list of ADDRESSES, and return the result as a single string."
+  "Normalize all ADDRESSES while adding PREFIX.
+Escape, trim, quote and add PREFIX to each address in list
+of ADDRESSES, and return the result as a single string."
   (mapconcat (lambda (x)
 	       (concat prefix "\""
 		       ;; escape double-quotes
@@ -2434,10 +2384,12 @@ the user (see `notmuch-show-stash-mlarchive-link-alist')."
 	     addresses " "))
 
 (put 'notmuch-show-stash-git-send-email 'notmuch-prefix-doc
-     "Copy From/To/Cc of current message to kill-ring in a form suitable for pasting to git send-email command line.")
+     "Copy From/To/Cc of current message to kill-ring.
+Use a form suitable for pasting to git send-email command line.")
 
 (defun notmuch-show-stash-git-send-email (&optional no-in-reply-to)
-  "Copy From/To/Cc/Message-Id of current message to kill-ring in a form suitable for pasting to git send-email command line.
+  "Copy From/To/Cc/Message-Id of current message to kill-ring.
+Use a form suitable for pasting to git send-email command line.
 
 If invoked with a prefix argument (or NO-IN-REPLY-TO is non-nil),
 omit --in-reply-to=<Message-Id>."
@@ -2457,7 +2409,7 @@ omit --in-reply-to=<Message-Id>."
 			  (list (notmuch-show-get-message-id t)) "--in-reply-to="))))
 	      " ")))
 
-;; Interactive part functions and their helpers
+;;; Interactive part functions and their helpers
 
 (defun notmuch-show-generate-part-buffer (msg part)
   "Return a temporary buffer containing the specified part's content."
@@ -2480,7 +2432,7 @@ MIME-TYPE is given then set the handle's mime-type to MIME-TYPE."
 	 (buf (notmuch-show-generate-part-buffer msg part))
 	 (computed-type (or mime-type (plist-get part :computed-type)))
 	 (filename (plist-get part :filename))
-	 (disposition (if filename `(attachment (filename . ,filename)))))
+	 (disposition (and filename `(attachment (filename . ,filename)))))
     (mm-make-handle buf (list computed-type) nil nil disposition)))
 
 (defun notmuch-show-apply-to-current-part-handle (fn &optional mime-type)
@@ -2490,10 +2442,9 @@ This ensures that the temporary buffer created for the mm-handle
 is destroyed when FN returns. If MIME-TYPE is given then force
 part to be treated as if it had that mime-type."
   (let ((handle (notmuch-show-current-part-handle mime-type)))
-    ;; emacs 24.3+ puts stdout/stderr into the calling buffer so we
-    ;; call it from a temp-buffer, unless
-    ;; notmuch-show-attachment-debug is non-nil in which case we put
-    ;; it in " *notmuch-part*".
+    ;; Emacs puts stdout/stderr into the calling buffer so we call
+    ;; it from a temp-buffer, unless notmuch-show-attachment-debug
+    ;; is non-nil, in which case we put it in " *notmuch-part*".
     (unwind-protect
 	(if notmuch-show-attachment-debug
 	    (with-current-buffer (generate-new-buffer " *notmuch-part*")
@@ -2533,7 +2484,6 @@ part to be treated as if it had that mime-type."
   (interactive)
   (notmuch-show-apply-to-current-part-handle #'mm-pipe-part))
 
-
 (defun notmuch-show--mm-display-part (handle)
   "Use mm-display-part to display HANDLE in a new buffer.
 
@@ -2541,7 +2491,7 @@ If the part is displayed in an external application then close
 the new buffer."
   (let ((buf (get-buffer-create (generate-new-buffer-name
 				 (concat " *notmuch-internal-part*")))))
-    (switch-to-buffer buf)
+    (pop-to-buffer-same-window buf)
     (if (eq (mm-display-part handle) 'external)
 	(kill-buffer buf)
       (goto-char (point-min))
@@ -2581,9 +2531,9 @@ beginning of the line."
 message."
   `(save-excursion
      (save-restriction
-      (let ((extent (notmuch-show-message-extent)))
-	(narrow-to-region (car extent) (cdr extent))
-	,@body))))
+       (let ((extent (notmuch-show-message-extent)))
+	 (narrow-to-region (car extent) (cdr extent))
+	 ,@body))))
 
 (defun notmuch-show--gather-urls ()
   "Gather any URLs in the current message."
@@ -2606,6 +2556,8 @@ browsing."
 	(funcall fn (completing-read prompt urls nil nil nil nil (car urls)))
       (message "No URLs found."))))
 
+;;; _
+
 (provide 'notmuch-show)
 
 ;;; notmuch-show.el ends here