(gnus-make-thread-indent-array): New optional arg specifying array size.

(gnus-summary-insert-line, gnus-summary-prepare-threads): Regrow indent
array if it is too small.
(gnus-sort-threads-recursive): Renamed from gnus-sort-thread-1.
(gnus-sort-threads-loop): New function.

1 files changed, 48 insertions, 17 deletions

diff --git a/lisp/gnus/gnus-sum.el b/lisp/gnus/gnus-sum.el
index 05d5614756b..55df66862c2 100644
--- a/lisp/gnus/gnus-sum.el
+++ b/lisp/gnus/gnus-sum.el
@@ -3343,16 +3343,17 @@ buffer that was in action when the last article was fetched."
       t
     (not (cdr (gnus-data-find-list article)))))
 
-(defun gnus-make-thread-indent-array ()
-  (let ((n 200))
-    (unless (and gnus-thread-indent-array
-                 (= gnus-thread-indent-level gnus-thread-indent-array-level))
-      (setq gnus-thread-indent-array (make-vector 201 "")
-            gnus-thread-indent-array-level gnus-thread-indent-level)
-      (while (>= n 0)
-        (aset gnus-thread-indent-array n
-              (make-string (* n gnus-thread-indent-level) ? ))
-        (setq n (1- n))))))
+(defun gnus-make-thread-indent-array (&optional n)
+  (when (or n
+            (progn (setq n 200) nil)
+            (null gnus-thread-indent-array)
+            (/= gnus-thread-indent-level gnus-thread-indent-array-level))
+    (setq gnus-thread-indent-array (make-vector (1+ n) "")
+          gnus-thread-indent-array-level gnus-thread-indent-level)
+    (while (>= n 0)
+      (aset gnus-thread-indent-array n
+            (make-string (* n gnus-thread-indent-level) ?\s))
+      (setq n (1- n)))))
 
 (defun gnus-update-summary-mark-positions ()
   "Compute where the summary marks are to go."
@@ -3451,6 +3452,9 @@ buffer that was in action when the last article was fetched."
                                  gnus-tmp-expirable gnus-tmp-subject-or-nil
                                  &optional gnus-tmp-dummy gnus-tmp-score
                                  gnus-tmp-process)
+  (if (>= gnus-tmp-level (length gnus-thread-indent-array))
+      (gnus-make-thread-indent-array (max (* 2 (length gnus-thread-indent-array))
+                                          gnus-tmp-level)))
   (let* ((gnus-tmp-indentation (aref gnus-thread-indent-array gnus-tmp-level))
          (gnus-tmp-lines (mail-header-lines gnus-tmp-header))
          (gnus-tmp-score (or gnus-tmp-score gnus-summary-default-score 0))
@@ -4549,23 +4553,46 @@ If LINE, insert the rebuilt thread starting on line LINE."
               (1+ (gnus-point-at-eol))
             (gnus-delete-line)))))))
 
-(defun gnus-sort-threads-1 (threads func)
+(defun gnus-sort-threads-recursive (threads func)
   (sort (mapcar (lambda (thread)
                   (cons (car thread)
                         (and (cdr thread)
-                             (gnus-sort-threads-1 (cdr thread) func))))
+                             (gnus-sort-threads-recursive (cdr thread) func))))
                 threads) func))
 
+(defun gnus-sort-threads-loop (threads func)
+  (let* ((superthread (cons nil threads))
+         (stack (list (cons superthread threads)))
+         remaining-threads thread)
+    (while stack
+      (setq remaining-threads (cdr (car stack)))
+      (if remaining-threads
+          (progn (setq thread (car remaining-threads))
+                 (setcdr (car stack) (cdr remaining-threads))
+                 (if (cdr thread)
+                     (push (cons thread (cdr thread)) stack)))
+        (setq thread (caar stack))
+        (setcdr thread (sort (cdr thread) func))
+        (pop stack)))
+    (cdr superthread)))
+
 (defun gnus-sort-threads (threads)
   "Sort THREADS."
   (if (not gnus-thread-sort-functions)
       threads
     (gnus-message 8 "Sorting threads...")
-    (let ((max-lisp-eval-depth (max 5000 max-lisp-eval-depth)))
-      (prog1 (gnus-sort-threads-1
-         threads
-         (gnus-make-sort-function gnus-thread-sort-functions))
-        (gnus-message 8 "Sorting threads...done")))))
+    (prog1
+        (condition-case nil
+            (let ((max-lisp-eval-depth (max max-lisp-eval-depth 5000)))
+              (gnus-sort-threads-recursive
+               threads (gnus-make-sort-function gnus-thread-sort-functions)))
+          ;; Even after binding max-lisp-eval-depth, the recursive
+          ;; sorter might fail for very long threads.  In that case,
+          ;; try using a (less well-tested) non-recursive sorter.
+          (error (gnus-sort-threads-loop
+                  threads (gnus-make-sort-function
+                           gnus-thread-sort-functions))))
+      (gnus-message 8 "Sorting threads...done"))))
 
 (defun gnus-sort-articles (articles)
   "Sort ARTICLES."
@@ -4990,6 +5017,10 @@ or a straight list of headers."
                       gnus-tmp-closing-bracket ?\>)
               (setq gnus-tmp-opening-bracket ?\[
                     gnus-tmp-closing-bracket ?\]))
+            (if (>= gnus-tmp-level (length gnus-thread-indent-array))
+                (gnus-make-thread-indent-array
+                 (max (* 2 (length gnus-thread-indent-array))
+                      gnus-tmp-level)))
             (setq
              gnus-tmp-indentation
              (aref gnus-thread-indent-array gnus-tmp-level)