From cea1424e92494e1933f16e3e3c266be75d188e35 Mon Sep 17 00:00:00 2001
From: Ken Olum <kdo@cosmos.phy.tufts.edu>
Date: Sat, 13 Sep 2014 12:01:56 +0300
Subject: [PATCH] Support rendering of HTML parts in Rmail (bug #4258).
lisp/mail/rmailmm.el (rmail-mime-process): Handle text/html
separately from other text/ types. Suppress tagline for
multipart body.
(rmail-mime-parse): Don't change visibility of tagline here.
(rmail-mime-set-bulk-data, rmail-mime-insert-bulk):
Handle text/html specially.
(rmail-mime-render-html-function,rmail-mime-prefer-html): New variables.
(rmail-mime-insert-html, rmail-mime-render-html-shr)
(rmail-mime-render-html-lynx): New functions.
(rmail-mime-fix-inserted-faces): New function.
(rmail-mime-process-multipart): Find the best part to show
following rmail-mime-prefer-html if set.
(rmail-mime-searching): New variable.
(rmail-search-mime-message): Bind rmail-mime-searching to
suppress rendering while searching.
---
lisp/ChangeLog | 19 +++++++
lisp/mail/rmailmm.el | 124 ++++++++++++++++++++++++++++++++++++++-----
2 files changed, 130 insertions(+), 13 deletions(-)
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 0e8672b9daf..59edd984774 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,22 @@
+2013-12-27 Ken Olum <kdo@cosmos.phy.tufts.edu>
+
+ Support rendering of HTML parts in Rmail (bug#4258).
+ * mail/rmailmm.el (rmail-mime-process): Handle text/html
+ separately from other text/ types. Suppress tagline for
+ multipart body.
+ (rmail-mime-parse): Don't change visibility of tagline here.
+ (rmail-mime-set-bulk-data, rmail-mime-insert-bulk):
+ Handle text/html specially.
+ (rmail-mime-render-html-function,rmail-mime-prefer-html): New variables.
+ (rmail-mime-insert-html, rmail-mime-render-html-shr)
+ (rmail-mime-render-html-lynx): New functions.
+ (rmail-mime-fix-inserted-faces): New function.
+ (rmail-mime-process-multipart): Find the best part to show
+ following rmail-mime-prefer-html if set.
+ (rmail-mime-searching): New variable.
+ (rmail-search-mime-message): Bind rmail-mime-searching to
+ suppress rendering while searching.
+
2014-09-12 Sam Steingold <sds@gnu.org>
* progmodes/sql.el (sql-product-alist): Add vertica.
diff --git a/lisp/mail/rmailmm.el b/lisp/mail/rmailmm.el
index 2c625f67e38..f28089762e6 100644
--- a/lisp/mail/rmailmm.el
+++ b/lisp/mail/rmailmm.el
@@ -131,6 +131,26 @@ automatically display the image in the buffer."
:version "23.2"
:group 'rmail-mime)
+(defcustom rmail-mime-render-html-function
+ (cond ((fboundp 'libxml-parse-html-region) 'rmail-mime-render-html-shr)
+ ((executable-find "lynx") 'rmail-mime-render-html-lynx)
+ (t nil))
+ "Function to convert HTML to text. Called with buffer containing HTML
+extracted from message in a temporary buffer. Converts to text in current
+buffer. If NIL, display HTML source."
+ :group 'rmail
+ :version "24.5"
+ :type '(choice function (const nil)))
+
+(defcustom rmail-mime-prefer-html
+ ;; Default to preferring HTML parts, but only if we have a renderer
+ (if rmail-mime-render-html-function t nil)
+ "If non-nil, default to showing HTML part rather than text part
+when both are available"
+ :group 'rmail
+ :version "24.5"
+ :type 'boolean)
+
;;; End of user options.
;;; Global variables that always have let-binding when referred.
@@ -150,6 +170,10 @@ processing MIME.")
The value is usually nil, and bound to non-nil while inserting
MIME entities.")
+(defvar rmail-mime-searching nil
+ "Bound to T inside `rmail-search-mime-message' to suppress expensive
+operations such as HTML decoding")
+
;;; MIME-entity object
(defun rmail-mime-entity (type disposition transfer-encoding
@@ -631,6 +655,57 @@ HEADER is a header component of a MIME-entity object (see
(insert-image (create-image data (cdr bulk-data) t))
(insert "\n")))
+(defun rmail-mime-insert-html (entity)
+ "Decode, render, and insert html from MIME-entity ENTITY."
+ (let ((body (rmail-mime-entity-body entity))
+ (transfer-encoding (rmail-mime-entity-transfer-encoding entity))
+ (buffer (current-buffer)))
+ (with-temp-buffer
+ (set-buffer-multibyte nil)
+ (setq buffer-undo-list t)
+ (insert-buffer-substring rmail-mime-mbox-buffer
+ (aref body 0) (aref body 1))
+ (cond ((string= transfer-encoding "base64")
+ (ignore-errors (base64-decode-region (point-min) (point-max))))
+ ((string= transfer-encoding "quoted-printable")
+ (quoted-printable-decode-region (point-min) (point-max))))
+ ;; Convert html in temporary buffer to text and insert in original buffer
+ (let ((source-buffer (current-buffer)))
+ (with-current-buffer buffer
+ (let ((start (point)))
+ (if rmail-mime-render-html-function
+ (funcall rmail-mime-render-html-function source-buffer)
+ (insert-buffer-substring source-buffer))
+ (rmail-mime-fix-inserted-faces start)))))))
+
+(defun rmail-mime-render-html-shr (source-buffer)
+ (let ((dom (with-current-buffer source-buffer
+ (libxml-parse-html-region (point-min) (point-max))))
+ ;; Image retrieval happens asynchronously, but meanwhile
+ ;; `rmail-swap-buffers' may have been run, leaving
+ ;; `shr-image-fetched' trying to insert the image in the wrong buffer.
+ (shr-inhibit-images t))
+ (shr-insert-document dom)))
+
+(defun rmail-mime-render-html-lynx (source-buffer)
+ (let ((destination-buffer (current-buffer)))
+ (with-current-buffer source-buffer
+ (call-process-region (point-min) (point-max)
+ "lynx" nil destination-buffer nil
+ "-stdin" "-dump" "-force_html"
+ "-dont_wrap_pre" "-width=70"))))
+
+;; Put font-lock-face properties matching face properties on text
+;; inserted, e.g., by shr, in text from START to point.
+(defun rmail-mime-fix-inserted-faces (start)
+ (while (< start (point))
+ (let ((face (get-text-property start 'face))
+ (next (next-single-property-change
+ start 'face (current-buffer) (point))))
+ (if face ; anything to do?
+ (put-text-property start next 'font-lock-face face))
+ (setq start next))))
+
(defun rmail-mime-toggle-button (button)
"Hide or show the body of the MIME-entity associated with BUTTON."
(save-excursion
@@ -675,6 +750,8 @@ directly."
(setq size (/ (* size 7) 3)))))))
(cond
+ ((string-match "text/html" content-type)
+ (setq type 'html))
((string-match "text/" content-type)
(setq type 'text))
((string-match "image/\\(.*\\)" content-type)
@@ -784,6 +861,12 @@ directly."
(if (rmail-mime-display-body new)
(cond ((eq (cdr bulk-data) 'text)
(rmail-mime-insert-decoded-text entity))
+ ((eq (cdr bulk-data) 'html)
+ ;; Render HTML if display single message, but if searching
+ ;; don't render but just search HTML itself.
+ (if rmail-mime-searching
+ (rmail-mime-insert-decoded-text entity)
+ (rmail-mime-insert-html entity)))
((cdr bulk-data)
(rmail-mime-insert-image entity))
(t
@@ -918,18 +1001,28 @@ The other arguments are the same as `rmail-mime-multipart-handler'."
(setq entities (nreverse entities))
(if (string-match "alternative" subtype)
;; Find the best entity to show, and hide all the others.
- (let (best second)
+ ;; If rmail-mime-prefer-html is set, html is best, then plain.
+ ;; If not, plain is best, then html.
+ ;; Then comes any other text part.
+ ;; If thereto of the same type, earlier entities in the message (later
+ ;; in the reverse list) are preferred.
+ (let (best best-priority)
(dolist (child entities)
(if (string= (or (car (rmail-mime-entity-disposition child))
(car content-disposition))
"inline")
- (if (string-match "text/plain"
- (car (rmail-mime-entity-type child)))
- (setq best child)
- (if (string-match "text/.*"
- (car (rmail-mime-entity-type child)))
- (setq second child)))))
- (or best (not second) (setq best second))
+ (let ((type (car (rmail-mime-entity-type child))))
+ (if (string-match "text/" type)
+ ;; Consider all inline text parts
+ (let ((priority
+ (cond ((string-match "text/html" type)
+ (if rmail-mime-prefer-html 1 2))
+ ((string-match "text/plain" type)
+ (if rmail-mime-prefer-html 2 1))
+ (t 3))))
+ (if (or (null best) (<= priority best-priority))
+ (setq best child
+ best-priority priority)))))))
(dolist (child entities)
(unless (eq best child)
(aset (rmail-mime-entity-body child) 2 nil)
@@ -1114,6 +1207,8 @@ modified."
(cond ((string-match "multipart/.*" (car content-type))
(save-restriction
(narrow-to-region (1- end) (point-max))
+ (if (zerop (length parse-tag)) ; top level of message
+ (aset new 1 (aset tagline 2 nil))) ; don't show tagline
(setq children (rmail-mime-process-multipart
content-type
content-disposition
@@ -1134,6 +1229,12 @@ modified."
(aset (rmail-mime-entity-tagline msg) 2 nil)
(setq children (list msg)
handler 'rmail-mime-insert-multipart))))
+ ((and is-inline (string-match "text/html" (car content-type)))
+ ;; Display tagline, so part can be detached
+ (aset new 1 (aset tagline 2 t))
+ (aset new 2 (aset body 2 t)) ; display body also.
+ (setq handler 'rmail-mime-insert-bulk))
+ ;; Inline non-HTML text
((and is-inline (string-match "text/" (car content-type)))
;; Don't need a tagline.
(aset new 1 (aset tagline 2 nil))
@@ -1186,10 +1287,6 @@ If an error occurs, return an error message string."
(new (aref (rmail-mime-entity-display entity) 1)))
;; Show header.
(aset new 0 (aset (rmail-mime-entity-header entity) 2 t))
- ;; Show tagline if and only if body is not shown.
- (if (aref new 2)
- (aset new 1 (aset (rmail-mime-entity-tagline entity) 2 nil))
- (aset new 1 (aset (rmail-mime-entity-tagline entity) 2 t)))
entity)))
(error (format "%s" err)))))
@@ -1390,7 +1487,8 @@ This is the usual value of `rmail-insert-mime-forwarded-message-function'."
"Function to set in `rmail-search-mime-message-function' (which see)."
(save-restriction
(narrow-to-region (rmail-msgbeg msg) (rmail-msgend msg))
- (let* ((rmail-mime-mbox-buffer (current-buffer))
+ (let* ((rmail-mime-searching t) ; mark inside search
+ (rmail-mime-mbox-buffer (current-buffer))
(rmail-mime-view-buffer rmail-view-buffer)
(header-end (save-excursion
(re-search-forward "^$" nil 'move) (point)))
--
2.39.5