[Emacs-diffs] /srv/bzr/emacs/trunk r108111: mail/rmailmm.el (rmail-show-mime): Catch an error caused by text decoding, and show a warning message without signalling an error (Bug#11282).

[Kenichi Handa]

------------------------------------------------------------
revno: 108111 [merge]
committer: Kenichi Handa <address@hidden>
branch nick: trunk
timestamp: Thu 2012-05-03 15:59:11 +0900
message:
  mail/rmailmm.el (rmail-show-mime): Catch an error caused by text decoding, 
and show a warning message without signalling an error (Bug#11282).
modified:
  lisp/ChangeLog
  lisp/mail/rmailmm.el

=== modified file 'lisp/ChangeLog'
--- a/lisp/ChangeLog    2012-05-03 02:39:23 +0000
+++ b/lisp/ChangeLog    2012-05-03 06:57:54 +0000
@@ -1,3 +1,9 @@
+2012-05-03  Kenichi Handa  <address@hidden>
+
+       * mail/rmailmm.el (rmail-show-mime): Catch an error caused by text
+       decoding, and show a warning message without signalling an error
+       (Bug#11282).
+
 2012-05-03  Stefan Monnier  <address@hidden>
 
        * emacs-lisp/bytecomp.el

=== modified file 'lisp/mail/rmailmm.el'
--- a/lisp/mail/rmailmm.el      2012-01-19 07:21:25 +0000
+++ b/lisp/mail/rmailmm.el      2012-05-03 05:47:24 +0000
@@ -1300,26 +1300,40 @@
        (rmail-mime-mbox-buffer rmail-buffer)
        (rmail-mime-view-buffer rmail-view-buffer)
        (rmail-mime-coding-system nil))
+    ;; If ENTITY is not a vector, it is a string describing an error.
     (if (vectorp entity)
        (with-current-buffer rmail-mime-view-buffer
          (erase-buffer)
-         (rmail-mime-insert entity)
-         (if (consp rmail-mime-coding-system)
-             ;; Decoding is done by rfc2047-decode-region only for a
-             ;; header.  But, as the used coding system may have been
-             ;; overridden by mm-charset-override-alist, we can't
-             ;; trust (car rmail-mime-coding-system).  So, here we
-             ;; try the decoding again with mm-charset-override-alist
-             ;; bound to nil.
-             (let ((mm-charset-override-alist nil))
-               (setq rmail-mime-coding-system
-                     (rmail-mime-find-header-encoding
-                      (rmail-mime-entity-header entity)))))
-         (set-buffer-file-coding-system
-          (if rmail-mime-coding-system
-              (coding-system-base rmail-mime-coding-system)
-            'undecided)
-          t t))
+         ;; This condition-case is for catching an error in the
+         ;; internal MIME decoding (e.g. incorrect BASE64 form) that
+         ;; may be signaled by rmail-mime-insert.
+         ;; FIXME: The current code doesn't set a proper error symbol
+         ;; in ERR.  We must find a way to propagate a correct error
+         ;; symbol that is caused in the very deep code of text
+         ;; decoding (e.g. an error by base64-decode-region called by
+         ;; post-read-conversion function of utf-7).
+         (condition-case err
+             (progn
+               (rmail-mime-insert entity)
+               (if (consp rmail-mime-coding-system)
+                   ;; Decoding is done by rfc2047-decode-region only for a
+                   ;; header.  But, as the used coding system may have been
+                   ;; overridden by mm-charset-override-alist, we can't
+                   ;; trust (car rmail-mime-coding-system).  So, here we
+                   ;; try the decoding again with mm-charset-override-alist
+                   ;; bound to nil.
+                   (let ((mm-charset-override-alist nil))
+                     (setq rmail-mime-coding-system
+                           (rmail-mime-find-header-encoding
+                            (rmail-mime-entity-header entity)))))
+               (set-buffer-file-coding-system
+                (if rmail-mime-coding-system
+                    (coding-system-base rmail-mime-coding-system)
+                  'undecided)
+                t t))
+           (error (setq entity (format "%s" err))))))
+    ;; Re-check ENTITY.  It may be set to an error string.
+    (when (stringp entity)
       ;; Decoding failed.  ENTITY is an error message.  Insert the
       ;; original message body as is, and show warning.
       (let ((region (with-current-buffer rmail-mime-mbox-buffer