[PATCH 3/3] emacs: Drop content-free "Unknown signature status" button

[Daniel Kahn Gillmor <dkg@fifthhorseman.net>]

When we have not been able to evaluate the signature status of a given
MIME part, showing a content-free (and interaction-free) "[ Unknown
signature status ]" button doesn't really help the user at all, and
takes up valuable screen real-estate.

A visual reminder that a given message is *not* signed isn't helpful
unless it is always present, in which case we'd want to see "[ Unknown
signature status ]" buttons on all messages, even ones that don't have
a signing structure, but i don't think we want that.
---
 emacs/notmuch-crypto.el                       | 27 ++++++++++---------
 .../notmuch-show-decrypted-message            |  1 -
 .../notmuch-show-decrypted-message-no-crypto  |  1 -
 ...notmuch-show-process-crypto-mime-parts-off |  1 -
 .../notmuch-show-undecryptable-message        |  1 -
 5 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/emacs/notmuch-crypto.el b/emacs/notmuch-crypto.el
index 353f721e..68171153 100644
--- a/emacs/notmuch-crypto.el
+++ b/emacs/notmuch-crypto.el
@@ -93,6 +93,7 @@ mode."
 (defun notmuch-crypto-insert-sigstatus-button (sigstatus from)
   (let* ((status (plist-get sigstatus :status))
 	 (help-msg nil)
+	 (show-button t)
 	 (label "Signature not processed")
 	 (face 'notmuch-crypto-signature-unknown)
 	 (button-action (lambda (button) (message (button-get button 'help-echo)))))
@@ -118,19 +119,21 @@ mode."
       (let ((keyid (concat "0x" (plist-get sigstatus :keyid))))
 	(setq label (concat "Bad signature (claimed key ID " keyid ")"))
 	(setq face 'notmuch-crypto-signature-bad)))
+     (status
+      (setq label (concat "Unknown signature status: " status)))
      (t
-      (setq label (concat "Unknown signature status"
-			  (if status (concat ": " status))))))
-    (insert-button
-     (concat "[ " label " ]")
-     :type 'notmuch-crypto-status-button-type
-     'help-echo help-msg
-     'face face
-     'mouse-face face
-     'action button-action
-     :notmuch-sigstatus sigstatus
-     :notmuch-from from)
-    (insert "\n")))
+      (setq show-button nil)))
+    (when show-button
+      (insert-button
+       (concat "[ " label " ]")
+       :type 'notmuch-crypto-status-button-type
+       'help-echo help-msg
+       'face face
+       'mouse-face face
+       'action button-action
+       :notmuch-sigstatus sigstatus
+       :notmuch-from from)
+      (insert "\n"))))
 
 (declare-function notmuch-show-refresh-view "notmuch-show" (&optional reset-state))
 
diff --git a/test/emacs-show.expected-output/notmuch-show-decrypted-message b/test/emacs-show.expected-output/notmuch-show-decrypted-message
index 08a9e4f6..c4ec4b32 100644
--- a/test/emacs-show.expected-output/notmuch-show-decrypted-message
+++ b/test/emacs-show.expected-output/notmuch-show-decrypted-message
@@ -5,7 +5,6 @@ Date: Sat, 01 Jan 2000 12:00:00 +0000
 
 [ multipart/encrypted ]
 [ Decryption successful ]
-[ Unknown signature status ]
 [ application/pgp-encrypted ]
 [ text/plain ]
 The password is "abcd1234!", please do not tell anyone.
diff --git a/test/emacs-show.expected-output/notmuch-show-decrypted-message-no-crypto b/test/emacs-show.expected-output/notmuch-show-decrypted-message-no-crypto
index e302e452..49d85337 100644
--- a/test/emacs-show.expected-output/notmuch-show-decrypted-message-no-crypto
+++ b/test/emacs-show.expected-output/notmuch-show-decrypted-message-no-crypto
@@ -5,6 +5,5 @@ Date: Sat, 01 Jan 2000 12:00:00 +0000
 
 [ multipart/encrypted ]
 [ Unknown encryption status ]
-[ Unknown signature status ]
 [ application/pgp-encrypted ]
 [ application/octet-stream ]
diff --git a/test/emacs-show.expected-output/notmuch-show-process-crypto-mime-parts-off b/test/emacs-show.expected-output/notmuch-show-process-crypto-mime-parts-off
index ce2892a0..3282c7b1 100644
--- a/test/emacs-show.expected-output/notmuch-show-process-crypto-mime-parts-off
+++ b/test/emacs-show.expected-output/notmuch-show-process-crypto-mime-parts-off
@@ -9,7 +9,6 @@ Subject: [notmuch] Working with Maildir storage?
 
   [ multipart/mixed ]
   [ multipart/signed ]
-  [ Unknown signature status ]
   [ text/plain ]
   > See the patch just posted here.
 
diff --git a/test/emacs-show.expected-output/notmuch-show-undecryptable-message b/test/emacs-show.expected-output/notmuch-show-undecryptable-message
index 530ff286..95c1646b 100644
--- a/test/emacs-show.expected-output/notmuch-show-undecryptable-message
+++ b/test/emacs-show.expected-output/notmuch-show-undecryptable-message
@@ -5,6 +5,5 @@ Date: Thu, 22 Dec 2016 08:34:56 -0400
 
 [ multipart/encrypted ]
 [ Decryption error ]
-[ Unknown signature status ]
 [ application/pgp-encrypted ]
 [ application/octet-stream ]
-- 
2.20.1