Fix the expunge operation.

pmail.el (pmail-only-expunge): Manage pmail-total-messages in the
callback handler; remove the extra show message call.
(pmail-expunge-callback): Rewrite to handle all possible conditions.

pmaildesc.el (pmail-desc-get-previous, pmail-desc-get-match-index):
New functions.

2 files changed, 35 insertions, 10 deletions

diff --git a/lisp/mail/pmail.el b/lisp/mail/pmail.el
index 09ec42d13e3..72abe896fbc 100644
--- a/lisp/mail/pmail.el
+++ b/lisp/mail/pmail.el
@@ -2622,10 +2622,8 @@ See also user-option `pmail-confirm-expunge'."
   ;; Remove the messages from the buffer and from the Pmail message
   ;; descriptor vector.
   (pmail-desc-prune-deleted-messages 'pmail-expunge-callback)
-  ;; Update the Pmail message counter, deal with the summary buffer,
-  ;; show the current message and update the User status.
-  (setq pmail-total-messages (pmail-desc-get-count))
-  (pmail-show-message pmail-current-message t)
+  ;; Deal with the summary buffer and update
+  ;; the User status.
   (let* ((omax (- (buffer-size) (point-max)))
          (omin (- (buffer-size) (point-min)))
          (opoint (if (and (> pmail-current-message 0)
@@ -2650,8 +2648,15 @@ See also user-option `pmail-confirm-expunge'."
 (defun pmail-expunge-callback (n)
   "Called after message N has been pruned to update the current Pmail
   message counter."
-  (if (< n pmail-current-message)
-      (setq pmail-current-message (1- pmail-current-message))))
+  ;; Process the various possible states to set the current message
+  ;; counter.
+  (setq pmail-total-messages (1- pmail-total-messages)
+        pmail-current-message
+        (cond
+         ((= 0 pmail-total-messages) 0)
+         ((> pmail-current-message n) (pmail-desc-get-previous pmail-desc-deleted-index n))
+         ((> pmail-current-message n) 0)
+         (t pmail-current-message))))
 
 ;;; mbox: ready
 (defun pmail-expunge ()
diff --git a/lisp/mail/pmaildesc.el b/lisp/mail/pmaildesc.el
index 09887d4b76a..f2274cc23cb 100644
--- a/lisp/mail/pmaildesc.el
+++ b/lisp/mail/pmaildesc.el
@@ -354,6 +354,27 @@ This includes the attributes."
   (nth pmail-desc-date-month-index
        (nth pmail-desc-date-index (pmail-desc-get-descriptor n))))
 
+(defun pmail-desc-get-previous (n attr-index &optional sense)
+  "Return the index for the previous matching descriptor.
+Starting with descriptor at index N locate the first previous
+descriptor such that the attribute ATTR is set.  SENSE, if
+non-null will reverse the sense of the attribute test."
+  (let ((index (1- n)) flag result)
+    (while (and (> index 0) (not result))
+      (if (listp (aref pmail-desc-vector index))
+          (setq result (pmail-desc-get-match-index attr-index sense index)))
+      (setq index (1- index)))
+    (or result 0)))
+
+(defun pmail-desc-get-match-index (attr-index sense n)
+  "Return the index N if the associated descriptor has a matching
+attribute, nil otherwise.  The attribute value must be set if
+SENSE is nil, or unset if SENSE is non-nil."
+  (let (flag (pmail-desc-attr-p attr-index n))
+    (if (or (and flag (not sense)) (and (not flag) sense))
+        n
+      nil)))
+
 (defun pmail-desc-get-sender (n)
   "Return the User registered as the mail sender."
   (nth pmail-desc-sender-index (pmail-desc-get-descriptor n)))
@@ -395,11 +416,10 @@ displayed in the Pmail summary buffer."
 Return the number of messages removed.  Invoke CALLBACK immediately
 after a message has been deleted.."
 
-  ;; Set the callback.
+  ;; Set the callback and remove all messages marked for deletion from
+  ;; the Pmail buffer and their descriptors from the Pmail message
+  ;; vector.
   (setq pmail-desc-delete-callback callback)
-
-  ;; Remove all messages marked for deletion from the Pmail buffer and
-  ;; their descriptors from the Pmail message vector.
   (let ((result (length (delq t (mapcar 'pmail-desc-delete-maybe
                                         (pmail-desc-make-index-list))))))
     (setq pmail-desc-vector