emacs: Improve the acquisition of text parts.

`notmuch-get-bodypart-text' assumed that it is always possible to
acquire text/* parts via the sexp output format. This is not true if the
part in question has a content type of application/octet-stream but is
being interpreted as text/* based on the extension of the part filename.

Rework `notmuch-get-bodypart-text' to use the raw output format to
address this and make the implementation common with that of
`notmuch-get-bodypart-binary'.

diff --git a/emacs/notmuch-lib.el b/emacs/notmuch-lib.el
index 89c01a578ccdfe331599f21fc3174d1e15807923..75a3706fa9aae99b309d8ba8f0aafd1392a25ce0 100644 (file)
--- a/emacs/notmuch-lib.el
+++ b/emacs/notmuch-lib.el
@@ -537,6 +537,34 @@ the given type."
    (lambda (part) (notmuch-match-content-type (plist-get part :content-type) type))
    parts))
 
+(defun notmuch--get-bodypart-raw (msg part process-crypto binaryp cache)
+  (let* ((plist-elem (if binaryp :content-binary :content))
+        (data (or (plist-get part plist-elem)
+                  (with-temp-buffer
+                    ;; Emacs internally uses a UTF-8-like multibyte string
+                    ;; representation by default (regardless of the coding
+                    ;; system, which only affects how it goes from outside data
+                    ;; to this internal representation).  This *almost* never
+                    ;; matters.  Annoyingly, it does matter if we use this data
+                    ;; in an image descriptor, since Emacs will use its internal
+                    ;; data buffer directly and this multibyte representation
+                    ;; corrupts binary image formats.  Since the caller is
+                    ;; asking for binary data, a unibyte string is a more
+                    ;; appropriate representation anyway.
+                    (when binaryp
+                      (set-buffer-multibyte nil))
+                    (let ((args `("show" "--format=raw"
+                                  ,(format "--part=%s" (plist-get part :id))
+                                  ,@(when process-crypto '("--decrypt"))
+                                  ,(notmuch-id-to-query (plist-get msg :id))))
+                          (coding-system-for-read
+                           (if binaryp 'no-conversion 'utf-8)))
+                      (apply #'call-process notmuch-command nil '(t nil) nil args)
+                      (buffer-string))))))
+    (when (and cache data)
+      (plist-put part plist-elem data))
+    data))
+
 (defun notmuch-get-bodypart-binary (msg part process-crypto &optional cache)
   "Return the unprocessed content of PART in MSG as a unibyte string.
 
@@ -547,57 +575,18 @@ this does no charset conversion.
 
 If CACHE is non-nil, the content of this part will be saved in
 MSG (if it isn't already)."
-  (let ((data (plist-get part :binary-content)))
-    (when (not data)
-      (let ((args `("show" "--format=raw"
-                   ,(format "--part=%d" (plist-get part :id))
-                   ,@(when process-crypto '("--decrypt"))
-                   ,(notmuch-id-to-query (plist-get msg :id)))))
-       (with-temp-buffer
-         ;; Emacs internally uses a UTF-8-like multibyte string
-         ;; representation by default (regardless of the coding
-         ;; system, which only affects how it goes from outside data
-         ;; to this internal representation).  This *almost* never
-         ;; matters.  Annoyingly, it does matter if we use this data
-         ;; in an image descriptor, since Emacs will use its internal
-         ;; data buffer directly and this multibyte representation
-         ;; corrupts binary image formats.  Since the caller is
-         ;; asking for binary data, a unibyte string is a more
-         ;; appropriate representation anyway.
-         (set-buffer-multibyte nil)
-         (let ((coding-system-for-read 'no-conversion))
-           (apply #'call-process notmuch-command nil '(t nil) nil args)
-           (setq data (buffer-string)))))
-      (when cache
-       ;; Cheat.  part is non-nil, and `plist-put' always modifies
-       ;; the list in place if it's non-nil.
-       (plist-put part :binary-content data)))
-    data))
+  (notmuch--get-bodypart-raw msg part process-crypto t cache))
 
 (defun notmuch-get-bodypart-text (msg part process-crypto &optional cache)
   "Return the text content of PART in MSG.
 
 This returns the content of the given part as a multibyte Lisp
 string after performing content transfer decoding and any
-necessary charset decoding.  It is an error to use this for
-non-text/* parts.
+necessary charset decoding.
 
 If CACHE is non-nil, the content of this part will be saved in
 MSG (if it isn't already)."
-  (let ((content (plist-get part :content)))
-    (when (not content)
-      ;; Use show --format=sexp to fetch decoded content
-      (let* ((args `("show" "--format=sexp" "--include-html"
-                    ,(format "--part=%s" (plist-get part :id))
-                    ,@(when process-crypto '("--decrypt"))
-                    ,(notmuch-id-to-query (plist-get msg :id))))
-            (npart (apply #'notmuch-call-notmuch-sexp args)))
-       (setq content (plist-get npart :content))
-       (when (not content)
-         (error "Internal error: No :content from %S" args)))
-      (when cache
-       (plist-put part :content content)))
-    content))
+  (notmuch--get-bodypart-raw msg part process-crypto nil cache))
 
 ;; Workaround: The call to `mm-display-part' below triggers a bug in
 ;; Emacs 24 if it attempts to use the shr renderer to display an HTML