Trouble viewing PDF attachments (with patches)

[peder@news.klingenberg.no (Peder O. Klingenberg)]

[-- Attachment #1: Type: text/plain, Size: 2040 bytes --]

Lately, all my attempts to view PDF attachments have ended in
'mailcap-save-binary-file instead of popping up xpdf like they used to.
After spending far to long last night digging through sources, the
culprit turned out to be Lars' commit f8b31759 from December 6, which
added the symbol doc-view-mode to mailcap-mime-data as a PDF viewer.[1]

This confused mm-display-part, which thought all methods should be
strings.  Removing that test passes doc-view-mode on to
mm-display-external, which already has provisions for funcalling
symbols.  That's what the first attached patch does.

However, the support for lisp-based "external" viewers in
mm-display-external seems not exactly complete.  When I tried to show
attachments with only the first patch applied, a doc-view-mode buffer
replaced my article buffer, but focus remained in the summary buffer,
and thus the keymaps were not those of DocView.

The second patch below tries to alleviate that, but I'm out of my depth
and not really happy with it.  What I wanted to do was to let DocView
(or in general, whatever lisp-based viewer mailcap would return) take
over the frame, and when I'm done with it, pop back to my gnus windows.
Ideally, I also think that it should be configurable to pop up a new
frame, so I can keep reading the article while looking at the PDF.

I settled instead for popping back to just the summary buffer, which
means another keystroke to reopen the article.  And the way I did that
seems ugly and hackish to me.  Thoughts?

(emacs copyright assignment is on file, should you choose to apply
either of these patches)

...Peder...

Footnotes: 
[1] I'm not really conviced that was a good idea, but there's no reason
    it shouldn't work in principle.  If it can be made to work as well
    as an external viewer, I'm probably in favour, as DocView in my
    already open emacs is much faster than spawning an external program
    when running X remotely over the wet string they label broadband.

-- 
I wish a new life awaited _me_ in some off-world colony.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0002-mm-decode.el-Make-non-string-display-methods-work.patch --]
[-- Type: text/x-diff, Size: 1879 bytes --]

From 741286e6b94fbbda876e26689aeb7b42a3e1c2f2 Mon Sep 17 00:00:00 2001
From: "Peder O. Klingenberg" <peder@klingenberg.no>
Date: Tue, 30 Dec 2014 10:00:25 +0100
Subject: [PATCH] mm-decode.el: Make non-string display methods work.

* mm-decode.el (mm-display-part): Make non-string methods work.
Non-string methods are funcalled and work just fine, the test was
bogus.

Signed-off-by: Peder O. Klingenberg <peder@klingenberg.no>
---
 lisp/ChangeLog    |  6 ++++++
 lisp/mm-decode.el | 10 +++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 786ee1b..2dfe657 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2014-12-30  Peder O. Klingenberg  <peder@klingenberg.no>
+
+	* mm-decode.el (mm-display-part): Make non-string methods work.
+	Non-string methods are funcalled and work just fine, the test was
+	bogus.
+
 2014-12-20  Katsumi Yamaoka  <yamaoka@jpl.org>
 
 	* registry.el (cl-remf, cl-loop, cl-subseq):
diff --git a/lisp/mm-decode.el b/lisp/mm-decode.el
index f5b4d7c..1b5ca9a 100644
--- a/lisp/mm-decode.el
+++ b/lisp/mm-decode.el
@@ -833,18 +833,18 @@ external if displayed external."
 		'inline)
 	    (setq external
 		  (and method	      ;; If nil, we always use "save".
-		       (stringp method) ;; 'mailcap-save-binary-file
 		       (or (eq mm-enable-external t)
 			   (and (eq mm-enable-external 'ask)
 				(y-or-n-p
 				 (concat
 				  "Display part (" type
-				  ") using external program"
-				  ;; Can non-string method ever happen?
+				  ") "
 				  (if (stringp method)
 				      (concat
-				       " \"" (format method filename) "\"")
-				    "")
+				       "using external program \""
+				       (format method filename) "\"")
+				    (format
+				     "by calling `%s' on the contents)" method))
 				  "? "))))))
 	    (if external
 		(mm-display-external
-- 
1.9.1


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #3: 0003-Show-external-lisp-viewers-in-whole-frame.patch --]
[-- Type: text/x-diff, Size: 1603 bytes --]

From ed90426bb18f17f0a06a32c4112d2b59c2bdda1d Mon Sep 17 00:00:00 2001
From: "Peder O. Klingenberg" <peder@klingenberg.no>
Date: Tue, 30 Dec 2014 11:28:12 +0100
Subject: [PATCH] Show "external" lisp viewers in whole frame.

* mm-decode.el (mm-display-external): Show "external" lisp viewers in
whole frame.

Signed-off-by: Peder O. Klingenberg <peder@klingenberg.no>
---
 lisp/ChangeLog    |  2 ++
 lisp/mm-decode.el | 10 +++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 2dfe657..a129284 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -3,6 +3,8 @@
 	* mm-decode.el (mm-display-part): Make non-string methods work.
 	Non-string methods are funcalled and work just fine, the test was
 	bogus.
+	* mm-decode.el (mm-display-external): Show "external" lisp viewers in
+	whole frame.
 
 2014-12-20  Katsumi Yamaoka  <yamaoka@jpl.org>
 
diff --git a/lisp/mm-decode.el b/lisp/mm-decode.el
index 1b5ca9a..fd12813 100644
--- a/lisp/mm-decode.el
+++ b/lisp/mm-decode.el
@@ -885,7 +885,15 @@ external if displayed external."
 				     (mm-handle-media-type handle) t))))
 	      (unwind-protect
 		  (if method
-		      (funcall method)
+		      (progn
+			(when (and (boundp 'gnus-summary-buffer)
+				   (bufferp gnus-summary-buffer)
+				   (buffer-name gnus-summary-buffer))
+			  ;; So that we pop back to the right place, sortof.
+			  (switch-to-buffer gnus-summary-buffer)
+			  (switch-to-buffer mm))
+			(delete-other-windows)
+			(funcall method))
 		    (mm-save-part handle))
 		(when (and (not non-viewer)
 			   method)
-- 
1.9.1