See ChangeLog

19 files changed, 348 insertions, 178 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b0353360325..3399619f343 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,9 @@
 2000-08-28  John Wiegley  <johnw@gnu.org>
 
+	* eshell/esh-util.el (eshell-flatten-list): It's not too wise to
+	have a defsubst call itself.  Made `eshell-flatten-list' back into
+	a function again.
+
 	* eshell/em-smart.el (eshell-smart-redisplay): Added a safety
 	catch, in case re-centering point at bottom messes up the display.
 	This happens frequently in Emacs 21, due I believe to variable
diff --git a/lisp/align.el b/lisp/align.el
index 0c7184678d7..4a3b098ec2b 100644
--- a/lisp/align.el
+++ b/lisp/align.el
@@ -873,7 +873,8 @@ on the format of these lists."
   (interactive "r")
   (let ((separator
 	 (or separate
-	     (if (symbolp align-region-separate)
+	     (if (and (symbolp align-region-separate)
+		      (boundp align-region-separate))
 		 (symbol-value align-region-separate)
 	       align-region-separate)
 	     'entire)))
@@ -1038,7 +1039,8 @@ to be colored."
 (defun align-newline-and-indent ()
   "A replacement function for `newline-and-indent', aligning as it goes."
   (interactive)
-  (let ((separate (or (if (symbolp align-region-separate)
+  (let ((separate (or (if (and (symbolp align-region-separate)
+			       (boundp align-region-separate))
 			  (symbol-value align-region-separate)
 			align-region-separate)
 		      'entire))
diff --git a/lisp/eshell/em-cmpl.el b/lisp/eshell/em-cmpl.el
index a0668f7d57a..19a0f595e6f 100644
--- a/lisp/eshell/em-cmpl.el
+++ b/lisp/eshell/em-cmpl.el
@@ -225,7 +225,12 @@ to writing a completion function."
   (documentation-property 'pcomplete-default-completion-function
 			  'variable-documentation)
   :type (get 'pcomplete-default-completion-function 'custom-type)
-  :group 'pcomplete)
+  :group 'eshell-cmpl)
+
+(defcustom eshell-cmpl-use-paring t
+  (documentation-property 'pcomplete-use-paring 'variable-documentation)
+  :type (get 'pcomplete-use-paring 'custom-type)
+  :group 'eshell-cmpl)
 
 ;;; Functions:
 
@@ -265,6 +270,8 @@ to writing a completion function."
        eshell-cmpl-cycle-cutoff-length)
   (set (make-local-variable 'pcomplete-restore-window-delay)
        eshell-cmpl-restore-window-delay)
+  (set (make-local-variable 'pcomplete-use-paring)
+       eshell-cmpl-use-paring)
   ;; `pcomplete-arg-quote-list' should only be set after all the
   ;; load-hooks for any other extension modules have been run, which
   ;; is true at the time `eshell-mode-hook' is run
diff --git a/lisp/eshell/em-dirs.el b/lisp/eshell/em-dirs.el
index 13565d87521..c59bd042575 100644
--- a/lisp/eshell/em-dirs.el
+++ b/lisp/eshell/em-dirs.el
@@ -382,11 +382,13 @@ in the minibuffer:
 		(index 0))
 	    (if (= len 0)
 		(error "Directory ring empty"))
+	    (eshell-init-print-buffer)
 	    (while (< index len)
-	      (eshell-printn
+	      (eshell-buffered-print
 	       (concat (number-to-string index) ": "
-		       (ring-ref eshell-last-dir-ring index)))
+		       (ring-ref eshell-last-dir-ring index) "\n"))
 	      (setq index (1+ index)))
+	    (eshell-flush)
 	    (setq handled t)))))
      (path
       (setq path (eshell-expand-multiple-dots path))))
diff --git a/lisp/eshell/em-hist.el b/lisp/eshell/em-hist.el
index 896178a7958..1213dfcc291 100644
--- a/lisp/eshell/em-hist.el
+++ b/lisp/eshell/em-hist.el
@@ -350,17 +350,13 @@ unless a different file is specified on the command line.")
 (defun eshell-put-history (input &optional ring at-beginning)
   "Put a new input line into the history ring."
   (unless ring (setq ring eshell-history-ring))
-  (subst-char-in-string ?\n ?\177 input t)
   (if at-beginning
       (ring-insert-at-beginning ring input)
     (ring-insert ring input)))
 
 (defun eshell-get-history (index &optional ring)
   "Get an input line from the history ring."
-  (unless ring (setq ring eshell-history-ring))
-  (let ((input (concat (ring-ref ring index))))
-    (subst-char-in-string ?\177 ?\n input t)
-    input))
+  (ring-ref (or ring eshell-history-ring) index))
 
 (defun eshell-add-to-history ()
   "Add INPUT to the history ring.
@@ -419,7 +415,8 @@ line, with the most recent command last.  See also
 	      (if (or (null ignore-dups)
 		      (ring-empty-p ring)
 		      (not (string-equal (ring-ref ring 0) history)))
-		  (ring-insert-at-beginning ring history)))
+		  (ring-insert-at-beginning
+		   ring (subst-char-in-string ?\177 ?\n history))))
 	    (setq count (1+ count))))
 	(setq eshell-history-ring ring
 	      eshell-history-index nil))))))
@@ -451,7 +448,9 @@ See also `eshell-read-history'."
 	(with-temp-buffer
 	  (while (> index 0)
 	    (setq index (1- index))
-	    (insert (ring-ref ring index) ?\n))
+	    (let ((start (point)))
+	      (insert (ring-ref ring index) ?\n)
+	      (subst-char-in-region start (1- (point)) ?\n ?\177)))
 	  (eshell-with-private-file-modes
 	   (write-region (point-min) (point-max) file append
 			 'no-message))))))))
@@ -891,7 +890,6 @@ If N is negative, search backwards for the -Nth previous match."
 	(goto-char eshell-last-output-end)
 	(delete-region (point) (point-max))
 	(when (and text (> (length text) 0))
-	  (subst-char-in-string ?\177 ?\n text t)
 	  (insert text)
 	  (put-text-property (1- (point)) (point)
 			     'last-search-pos before)
diff --git a/lisp/eshell/em-ls.el b/lisp/eshell/em-ls.el
index e9e46c2f1a6..cd16f049815 100644
--- a/lisp/eshell/em-ls.el
+++ b/lisp/eshell/em-ls.el
@@ -820,7 +820,7 @@ Use TRUENAME for predicate tests, if passed."
 	      ((not (eshell-ls-filetype-p (cdr file) ?-))
 	       'eshell-ls-special-face)
 
-	      ((and (not (= (user-uid) 0)) ; root can execute anything
+	      ((and (/= (user-uid) 0) ; root can execute anything
 		    (eshell-ls-applicable (cdr file) 3
 					  'file-executable-p (car file)))
 	       'eshell-ls-executable-face)
diff --git a/lisp/eshell/em-rebind.el b/lisp/eshell/em-rebind.el
index bd5ee5f5292..0463a78ffb4 100644
--- a/lisp/eshell/em-rebind.el
+++ b/lisp/eshell/em-rebind.el
@@ -235,7 +235,7 @@ input."
   (let ((proc (get-buffer-process (current-buffer))))
     (if (eobp)
 	(cond
-	 ((not (= (point) eshell-last-output-end))
+	 ((/= (point) eshell-last-output-end)
 	  (beep))
 	 (proc
 	  (process-send-eof))
diff --git a/lisp/eshell/em-smart.el b/lisp/eshell/em-smart.el
index 0d5a2732dd5..d7db23a0f9b 100644
--- a/lisp/eshell/em-smart.el
+++ b/lisp/eshell/em-smart.el
@@ -258,15 +258,20 @@ and the end of the buffer are still visible."
   "Display as much output as possible, smartly."
   (if (eobp)
       (recenter -1)
-    (and (memq 'eshell-smart-display-move pre-command-hook)
-	 (>= (point) eshell-last-input-start)
-	 (< (point) eshell-last-input-end)
-	 (set-window-start (selected-window)
-			   (line-beginning-position) t))
-    (if (pos-visible-in-window-p (point-max))
-	(save-excursion
-	  (goto-char (point-max))
-	  (recenter -1)))))
+    (let ((top-point (point)))
+      (and (memq 'eshell-smart-display-move pre-command-hook)
+	   (>= (point) eshell-last-input-start)
+	   (< (point) eshell-last-input-end)
+	   (set-window-start (selected-window)
+			     (line-beginning-position) t))
+      (if (pos-visible-in-window-p (point-max))
+	  (save-excursion
+	    (goto-char (point-max))
+	    (recenter -1)
+	    (unless (pos-visible-in-window-p top-point)
+	      (goto-char top-point)
+	      (set-window-start (selected-window)
+				(line-beginning-position) t)))))))
 
 (defun eshell-smart-goto-end ()
   "Like `end-of-buffer', but do not push a mark."
diff --git a/lisp/eshell/em-unix.el b/lisp/eshell/em-unix.el
index 33a99cb06a3..17e110f65ed 100644
--- a/lisp/eshell/em-unix.el
+++ b/lisp/eshell/em-unix.el
@@ -117,7 +117,7 @@ Otherwise, `rmdir' is required."
   :type 'boolean
   :group 'eshell-unix)
 
-(defcustom eshell-ln-overwrite-files t
+(defcustom eshell-ln-overwrite-files nil
   "*If non-nil, `ln' will overwrite files without warning."
   :type 'boolean
   :group 'eshell-unix)
@@ -224,7 +224,7 @@ Remove (unlink) the FILE(s).")
 			  (not (y-or-n-p (format "rm: delete buffer `%s'? "
 						 entry)))))
 	   (eshell-funcalln 'kill-buffer entry)))
-	((processp entry)
+	((eshell-processp entry)
 	 (if verbose
 	     (eshell-printn (format "rm: killing process `%s'" entry)))
 	 (unless (or preview
@@ -353,13 +353,14 @@ Remove the DIRECTORY(ies), if they are empty.")
 				 command target)))
 		    (unless preview
 		      (eshell-funcalln 'make-directory target)))
-		  (eshell-shuffle-files command action
-					(mapcar
-					 (function
-					  (lambda (file)
-					    (concat source "/" file)))
-					 (directory-files source))
-					target func t args)
+		  (apply 'eshell-shuffle-files
+			 command action
+			 (mapcar
+			  (function
+			   (lambda (file)
+			     (concat source "/" file)))
+			  (directory-files source))
+			 target func t args)
 		  (when (eq func 'rename-file)
 		    (if verbose
 			(eshell-printn
@@ -527,7 +528,7 @@ with '--symbolic'.  When creating hard links, each TARGET must exist.")
   "Implementation of cat in Lisp."
   (if eshell-in-pipeline-p
       (throw 'eshell-replace-command
-	     (eshell-parse-command "*cat" args))
+	     (eshell-parse-command "*cat" (eshell-flatten-list args)))
     (eshell-init-print-buffer)
     (eshell-eval-using-options
      "cat" args
@@ -568,7 +569,7 @@ Concatenate FILE(s), or standard input, to standard output.")
 			 (list 'quote (eshell-copy-environment))))))
 	(compile (concat "make " (eshell-flatten-and-stringify args))))
     (throw 'eshell-replace-command
-	   (eshell-parse-command "*make" args))))
+	   (eshell-parse-command "*make" (eshell-flatten-list args)))))
 
 (defun eshell-occur-mode-goto-occurrence ()
   "Go to the occurrence the current line describes."
@@ -644,7 +645,8 @@ external command."
 		      (not eshell-in-pipeline-p)
 		      (not eshell-in-subcommand-p))))
 	(throw 'eshell-replace-command
-	       (eshell-parse-command (concat "*" command) args))
+	       (eshell-parse-command (concat "*" command)
+				     (eshell-flatten-list args)))
       (let* ((compilation-process-setup-function
 	      (list 'lambda nil
 		    (list 'setq 'process-environment
@@ -745,8 +747,8 @@ external command."
 			     (cadr (car entries)))))
 	  (unless (or (and symlink (not dereference-links))
 		      (and only-one-filesystem
-			   (not (= only-one-filesystem
-				   (nth 12 (car entries))))))
+			   (/= only-one-filesystem
+			       (nth 12 (car entries)))))
 	    (if symlink
 		(setq entry symlink))
 	    (setq size
@@ -769,10 +771,10 @@ external command."
     size))
 
 (defun eshell/du (&rest args)
-  "Implementation of \"du\" in Lisp, passing RAGS."
+  "Implementation of \"du\" in Lisp, passing ARGS."
   (if (eshell-search-path "du")
       (throw 'eshell-replace-command
-	     (eshell-parse-command "*du" args))
+	     (eshell-parse-command "*du" (eshell-flatten-list args)))
     (eshell-eval-using-options
      "du" args
      '((?a "all" nil show-all
@@ -875,32 +877,38 @@ Show wall-clock time elapsed during execution of COMMAND.")
 
 (defun eshell/diff (&rest args)
   "Alias \"diff\" to call Emacs `diff' function."
-  (if (or eshell-plain-diff-behavior
-	  (not (and (eshell-interactive-output-p)
-		    (not eshell-in-pipeline-p)
-		    (not eshell-in-subcommand-p))))
-      (throw 'eshell-replace-command
-	     (eshell-parse-command "*diff" args))
-    (setq args (eshell-flatten-list args))
-    (if (< (length args) 2)
-	(error "diff: missing operand"))
-    (let ((old (car (last args 2)))
-	  (new (car (last args)))
-	  (config (current-window-configuration)))
-      (if (= (length args) 2)
-	  (setq args nil)
-	(setcdr (last args 3) nil))
-      (with-current-buffer
-	  (diff old new (eshell-flatten-and-stringify args))
-	(when (fboundp 'diff-mode)
-	  (diff-mode)
-	  (set (make-local-variable 'eshell-diff-window-config) config)
-	  (local-set-key [?q] 'eshell-diff-quit)
-	  (if (fboundp 'turn-on-font-lock-if-enabled)
-	      (turn-on-font-lock-if-enabled))))
-      (other-window 1)
-      (goto-char (point-min))
-      nil)))
+  (let ((orig-args (eshell-flatten-list args)))
+    (if (or eshell-plain-diff-behavior
+	    (not (and (eshell-interactive-output-p)
+		      (not eshell-in-pipeline-p)
+		      (not eshell-in-subcommand-p))))
+	(throw 'eshell-replace-command
+	       (eshell-parse-command "*diff" orig-args))
+      (setq args (eshell-copy-list orig-args))
+      (if (< (length args) 2)
+	  (throw 'eshell-replace-command
+		 (eshell-parse-command "*diff" orig-args)))
+      (let ((old (car (last args 2)))
+	    (new (car (last args)))
+	    (config (current-window-configuration)))
+	(if (= (length args) 2)
+	    (setq args nil)
+	  (setcdr (last args 3) nil))
+	(with-current-buffer
+	    (condition-case err
+		(diff old new (eshell-flatten-and-stringify args))
+	      (error
+	       (throw 'eshell-replace-command
+		      (eshell-parse-command "*diff" orig-args))))
+	  (when (fboundp 'diff-mode)
+	    (diff-mode)
+	    (set (make-local-variable 'eshell-diff-window-config) config)
+	    (local-set-key [?q] 'eshell-diff-quit)
+	    (if (fboundp 'turn-on-font-lock-if-enabled)
+		(turn-on-font-lock-if-enabled))))
+	(other-window 1)
+	(goto-char (point-min))
+	nil))))
 
 (defun eshell/locate (&rest args)
   "Alias \"locate\" to call Emacs `locate' function."
@@ -911,7 +919,7 @@ Show wall-clock time elapsed during execution of COMMAND.")
 	  (and (stringp (car args))
 	       (string-match "^-" (car args))))
       (throw 'eshell-replace-command
-	     (eshell-parse-command "*locate" args))
+	     (eshell-parse-command "*locate" (eshell-flatten-list args)))
     (save-selected-window
       (let ((locate-history-list (list (car args))))
 	(locate-with-filter (car args) (cadr args))))))
diff --git a/lisp/eshell/em-xtra.el b/lisp/eshell/em-xtra.el
index ad5602d97a0..9b4e6ad058e 100644
--- a/lisp/eshell/em-xtra.el
+++ b/lisp/eshell/em-xtra.el
@@ -41,7 +41,7 @@ naturally accessible within Emacs."
   "Implementation of expr, using the calc package."
   (if (not (fboundp 'calc-eval))
       (throw 'eshell-replace-command
-	     (eshell-parse-command "*expr" args))
+	     (eshell-parse-command "*expr" (eshell-flatten-list args)))
     ;; to fool the byte-compiler...
     (let ((func 'calc-eval))
       (funcall func (eshell-flatten-and-stringify args)))))
diff --git a/lisp/eshell/esh-cmd.el b/lisp/eshell/esh-cmd.el
index a3c7d58c066..fcdcfbb3fc3 100644
--- a/lisp/eshell/esh-cmd.el
+++ b/lisp/eshell/esh-cmd.el
@@ -516,8 +516,8 @@ implemented via rewriting, rather than as a function."
 			      (list 'car
 				    (list 'symbol-value
 					  (list 'quote 'for-items)))))
-		  (list 'eshell-protect
-			(eshell-invokify-arg body t)))
+		  (list 'eshell-copy-handles
+			 (eshell-invokify-arg body t)))
 	    (list 'setcar 'for-items
 		  (list 'cadr
 			(list 'symbol-value
@@ -581,7 +581,7 @@ must be implemented via rewriting, rather than as a function."
       (eshell-structure-basic-command
        'while '("while" "until") (car terms)
        (eshell-invokify-arg (cadr terms) nil t)
-       (list 'eshell-protect
+       (list 'eshell-copy-handles
 	     (eshell-invokify-arg (car (last terms)) t)))))
 
 (defun eshell-rewrite-if-command (terms)
@@ -770,6 +770,31 @@ this grossness will be made to disappear by using `call/cc'..."
 	(eshell-errorn (error-message-string err))
 	(eshell-close-handles 1)))))
 
+;; (defun eshell-copy-or-protect-handles ()
+;;   (if (eshell-processp (car (aref eshell-current-handles
+;; 				  eshell-output-handle)))
+;;       (eshell-protect-handles eshell-current-handles)
+;;     (eshell-create-handles
+;;      (car (aref eshell-current-handles
+;; 		eshell-output-handle)) nil
+;;      (car (aref eshell-current-handles
+;; 		eshell-error-handle)) nil)))
+
+;; (defmacro eshell-copy-handles (object)
+;;   "Duplicate current I/O handles, so OBJECT works with its own copy."
+;;   `(let ((eshell-current-handles (eshell-copy-or-protect-handles)))
+;;      ,object))
+
+(defmacro eshell-copy-handles (object)
+  "Duplicate current I/O handles, so OBJECT works with its own copy."
+  `(let ((eshell-current-handles
+	  (eshell-create-handles
+	   (car (aref eshell-current-handles
+		      eshell-output-handle)) nil
+	   (car (aref eshell-current-handles
+		      eshell-error-handle)) nil)))
+     ,object))
+
 (defmacro eshell-protect (object)
   "Protect I/O handles, so they aren't get closed after eval'ing OBJECT."
   `(progn
@@ -779,32 +804,65 @@ this grossness will be made to disappear by using `call/cc'..."
 (defmacro eshell-do-pipelines (pipeline)
   "Execute the commands in PIPELINE, connecting each to one another."
   (when (setq pipeline (cadr pipeline))
-    `(let ((eshell-current-handles
-	    (eshell-create-handles
-	     (car (aref eshell-current-handles
-			eshell-output-handle)) nil
-	     (car (aref eshell-current-handles
-			eshell-error-handle)) nil)))
+    `(eshell-copy-handles
+      (progn
+	,(when (cdr pipeline)
+	   `(let (nextproc)
+	      (progn
+		(set 'nextproc
+		     (eshell-do-pipelines (quote ,(cdr pipeline))))
+		(eshell-set-output-handle ,eshell-output-handle
+					  'append nextproc)
+		(eshell-set-output-handle ,eshell-error-handle
+					  'append nextproc)
+		(set 'tailproc (or tailproc nextproc)))))
+	,(let ((head (car pipeline)))
+	   (if (memq (car head) '(let progn))
+	       (setq head (car (last head))))
+	   (when (memq (car head) eshell-deferrable-commands)
+	     (ignore
+	      (setcar head
+		      (intern-soft
+		       (concat (symbol-name (car head)) "*"))))))
+	,(car pipeline)))))
+
+(defmacro eshell-do-pipelines-synchronously (pipeline)
+  "Execute the commands in PIPELINE in sequence synchronously.
+Output of each command is passed as input to the next one in the pipeline.
+This is used on systems where `start-process' is not supported."
+  (when (setq pipeline (cadr pipeline))
+    `(let (result)
        (progn
 	 ,(when (cdr pipeline)
-	    `(let (nextproc)
+	    `(let (output-marker)
 	       (progn
-		 (set 'nextproc
-		      (eshell-do-pipelines (quote ,(cdr pipeline))))
+		 (set 'output-marker ,(point-marker))
 		 (eshell-set-output-handle ,eshell-output-handle
-					   'append nextproc)
+					   'append output-marker)
 		 (eshell-set-output-handle ,eshell-error-handle
-					   'append nextproc)
-		 (set 'tailproc (or tailproc nextproc)))))
+					   'append output-marker))))
 	 ,(let ((head (car pipeline)))
 	    (if (memq (car head) '(let progn))
 		(setq head (car (last head))))
+	    ;;; FIXME: is deferrable significant here?
 	    (when (memq (car head) eshell-deferrable-commands)
 	      (ignore
 	       (setcar head
 		       (intern-soft
 			(concat (symbol-name (car head)) "*"))))))
-	 ,(car pipeline)))))
+	 ;; The last process in the pipe should get its handles
+	 ;; redirected as we found them before running the pipe.
+	 ,(if (null (cdr pipeline))
+	      `(progn
+		 (set 'eshell-current-handles tail-handles)
+		 (set 'eshell-in-pipeline-p nil)))
+	 (set 'result ,(car pipeline))
+	 ;; tailproc gets the result of the last successful process in
+	 ;; the pipeline.
+	 (set 'tailproc (or result tailproc))
+	 ,(if (cdr pipeline)
+	      `(eshell-do-pipelines-synchronously (quote ,(cdr pipeline))))
+	 result))))
 
 (defalias 'eshell-process-identity 'identity)
 
@@ -812,7 +870,14 @@ this grossness will be made to disappear by using `call/cc'..."
   "Execute the commands in PIPELINE, connecting each to one another."
   `(let ((eshell-in-pipeline-p t) tailproc)
      (progn
-       (eshell-do-pipelines ,pipeline)
+       ,(if (fboundp 'start-process)
+	    `(eshell-do-pipelines ,pipeline)
+	  `(let ((tail-handles (eshell-create-handles
+				(car (aref eshell-current-handles
+					   ,eshell-output-handle)) nil
+				(car (aref eshell-current-handles
+					   ,eshell-error-handle)) nil)))
+	     (eshell-do-pipelines-synchronously ,pipeline)))
        (eshell-process-identity tailproc))))
 
 (defmacro eshell-as-subcommand (command)
@@ -919,12 +984,19 @@ at the moment are:
 	     (erase-buffer)
 	     (insert "command: \"" input "\"\n"))))
     (setq eshell-current-command command)
-    (eshell-resume-eval)))
+    (let ((delim (catch 'eshell-incomplete
+		   (eshell-resume-eval))))
+      (if delim
+	  (error "Unmatched delimiter: %c"
+		 (if (listp delim)
+		     (car delim)
+		   delim))))))
 
 (defun eshell-resume-command (proc status)
   "Resume the current command when a process ends."
   (when proc
-    (unless (or (string= "stopped" status)
+    (unless (or (not (stringp status))
+		(string= "stopped" status)
 		(string-match eshell-reset-signals status))
       (if (eq proc (eshell-interactive-process))
 	  (eshell-resume-eval)))))
@@ -941,7 +1013,7 @@ at the moment are:
 			  (setq retval
 				(eshell-do-eval
 				 eshell-current-command))))))
-	    (if proc
+	    (if (eshell-processp proc)
 		(ignore (setq eshell-last-async-proc proc))
 	      (cadr retval)))))
     (error
@@ -1019,38 +1091,31 @@ be finished later after the completion of an asynchronous subprocess."
 	(when (car eshell-command-body)
 	  (assert (not synchronous-p))
 	  (eshell-do-eval (car eshell-command-body))
-	  (setcar eshell-command-body nil))
+	  (setcar eshell-command-body nil)
+	  (setcar eshell-test-body nil))
 	(unless (car eshell-test-body)
 	  (setcar eshell-test-body (eshell-copy-tree (car args))))
-	(if (and (car eshell-test-body)
-		 (not (eq (car eshell-test-body) 0)))
-	    (while (cadr (eshell-do-eval (car eshell-test-body)))
-	      (setcar eshell-test-body 0)
-	      (setcar eshell-command-body (eshell-copy-tree (cadr args)))
-	      (eshell-do-eval (car eshell-command-body) synchronous-p)
-	      (setcar eshell-command-body nil)
-	      (setcar eshell-test-body (eshell-copy-tree (car args)))))
+	(while (cadr (eshell-do-eval (car eshell-test-body)))
+	  (setcar eshell-command-body (eshell-copy-tree (cadr args)))
+	  (eshell-do-eval (car eshell-command-body) synchronous-p)
+	  (setcar eshell-command-body nil)
+	  (setcar eshell-test-body (eshell-copy-tree (car args))))
 	(setcar eshell-command-body nil))
        ((eq (car form) 'if)
 	;; `eshell-copy-tree' is needed here so that the test argument
 	;; doesn't get modified and thus always yield the same result.
-	(when (car eshell-command-body)
-	  (assert (not synchronous-p))
-	  (eshell-do-eval (car eshell-command-body))
-	  (setcar eshell-command-body nil))
-	(unless (car eshell-test-body)
-	  (setcar eshell-test-body (eshell-copy-tree (car args))))
-	(if (and (car eshell-test-body)
-		 (not (eq (car eshell-test-body) 0)))
-	    (if (cadr (eshell-do-eval (car eshell-test-body)))
-		(progn
-		  (setcar eshell-test-body 0)
-		  (setcar eshell-command-body (eshell-copy-tree (cadr args)))
-		  (eshell-do-eval (car eshell-command-body) synchronous-p))
-	      (setcar eshell-test-body 0)
-	      (setcar eshell-command-body (eshell-copy-tree (car (cddr args))))
-	      (eshell-do-eval (car eshell-command-body) synchronous-p)))
-	(setcar eshell-command-body nil))
+	(if (car eshell-command-body)
+	    (progn
+	      (assert (not synchronous-p))
+	      (eshell-do-eval (car eshell-command-body)))
+	  (unless (car eshell-test-body)
+	    (setcar eshell-test-body (eshell-copy-tree (car args))))
+	  (if (cadr (eshell-do-eval (car eshell-test-body)))
+	      (setcar eshell-command-body (eshell-copy-tree (cadr args)))
+	    (setcar eshell-command-body (eshell-copy-tree (car (cddr args)))))
+	  (eshell-do-eval (car eshell-command-body) synchronous-p))
+	(setcar eshell-command-body nil)
+	(setcar eshell-test-body nil))
        ((eq (car form) 'setcar)
 	(setcar (cdr args) (eshell-do-eval (cadr args) synchronous-p))
 	(eval form))
@@ -1131,7 +1196,7 @@ be finished later after the completion of an asynchronous subprocess."
 	      (if (and (memq (car form) eshell-deferrable-commands)
 		       (not eshell-current-subjob-p)
 		       result
-		       (processp result))
+		       (eshell-processp result))
 		  (if synchronous-p
 		      (eshell/wait result)
 		    (eshell-manipulate "inserting ignore form"
@@ -1172,7 +1237,8 @@ be finished later after the completion of an asynchronous subprocess."
 		(setq desc (substring desc 0
 				      (1- (or (string-match "\n" desc)
 					      (length desc)))))
-		(kill-buffer "*Help*")
+		(if (buffer-live-p (get-buffer "*Help*"))
+		    (kill-buffer "*Help*"))
 		(setq program (or desc name))))))
       (if (not program)
 	  (eshell-error (format "which: no %s in (%s)\n"
diff --git a/lisp/eshell/esh-ext.el b/lisp/eshell/esh-ext.el
index c4d031131a7..3aec7f22fd8 100644
--- a/lisp/eshell/esh-ext.el
+++ b/lisp/eshell/esh-ext.el
@@ -103,11 +103,9 @@ wholly ignored."
   "Invoke a .BAT or .CMD file on DOS/Windows systems."
   ;; since CMD.EXE can't handle forward slashes in the initial
   ;; argument...
-  (setcar args (subst-char-in-string directory-sep-char
-				     ?\\ (car args)))
+  (setcar args (subst-char-in-string directory-sep-char ?\\ (car args)))
   (throw 'eshell-replace-command
-	 (eshell-parse-command eshell-windows-shell-file
-			       (cons "/c" args))))
+	 (eshell-parse-command eshell-windows-shell-file (cons "/c" args))))
 
 (defcustom eshell-interpreter-alist
   (if (eshell-under-windows-p)
diff --git a/lisp/eshell/esh-io.el b/lisp/eshell/esh-io.el
index f59c1ef47b2..84dbbc18e07 100644
--- a/lisp/eshell/esh-io.el
+++ b/lisp/eshell/esh-io.el
@@ -132,8 +132,8 @@ the function is expected to return another function -- which is the
 output function.  Otherwise, the second element itself is the output
 function.
 
-The output function is then called repeatedly with a single strings,
-with represents success pieces of the output of the command, until nil
+The output function is then called repeatedly with single strings,
+which represents successive pieces of the output of the command, until nil
 is passed, meaning EOF.
 
 NOTE: /dev/null is handled specially as a virtual target, and should
@@ -231,7 +231,9 @@ not be added to this variable."
   (standard-output output-mode &optional standard-error error-mode)
   "Create a new set of file handles for a command.
 The default location for standard output and standard error will go to
-STANDARD-OUTPUT and STANDARD-ERROR, respectively."
+STANDARD-OUTPUT and STANDARD-ERROR, respectively.
+OUTPUT-MODE and ERROR-MODE are either `overwrite', `append' or `insert';
+a nil value of mode defaults to `insert'."
   (let ((handles (make-vector eshell-number-of-handles nil))
 	(output-target (eshell-get-target standard-output output-mode))
 	(error-target (eshell-get-target standard-error error-mode)))
@@ -272,7 +274,7 @@ STATUS should be non-nil on successful termination of the output."
 
    ;; If we're redirecting to a process (via a pipe, or process
    ;; redirection), send it EOF so that it knows we're finished.
-   ((processp target)
+   ((eshell-processp target)
     (if (eq (process-status target) 'run)
 	(process-send-eof target)))
 
@@ -326,7 +328,8 @@ last execution result should not be changed."
 
 (defun eshell-get-target (target &optional mode)
   "Convert TARGET, which is a raw argument, into a valid output target.
-MODE is either `overwrite', `append' or `insert'."
+MODE is either `overwrite', `append' or `insert'; if it is omitted or nil,
+it defaults to `insert'."
   (setq mode (or mode 'insert))
   (cond
    ((stringp target)
@@ -367,7 +370,7 @@ MODE is either `overwrite', `append' or `insert'."
     (if (eq mode 'overwrite)
 	(set target nil))
     target)
-   ((or (processp target)
+   ((or (eshell-processp target)
 	(markerp target))
     target)
    (t
@@ -394,7 +397,7 @@ MODE is either `overwrite', `append' or `insert'."
 	(if (and (listp current)
 		 (not (member where current)))
 	    (setq current (append current (list where)))
-	  (setq current (list where)))
+	  (setq current where))
 	(if (not (aref eshell-current-handles index))
 	    (aset eshell-current-handles index (cons nil 1)))
 	(setcar (aref eshell-current-handles index) current)))))
@@ -438,20 +441,20 @@ after all printing is over with no argument."
 	  eshell-print-queue-count (1+ eshell-print-queue-count))))
 
 (defsubst eshell-print (object)
-  "Output OBJECT to the error handle."
+  "Output OBJECT to the standard output handle."
   (eshell-output-object object eshell-output-handle))
 
 (defsubst eshell-error (object)
-  "Output OBJECT to the error handle."
+  "Output OBJECT to the standard error handle."
   (eshell-output-object object eshell-error-handle))
 
 (defsubst eshell-errorn (object)
-  "Output OBJECT to the error handle."
+  "Output OBJECT followed by a newline to the standard error handle."
   (eshell-error object)
   (eshell-error "\n"))
 
 (defsubst eshell-printn (object)
-  "Output OBJECT to the error handle."
+  "Output OBJECT followed by a newline to the standard output handle."
   (eshell-print object)
   (eshell-print "\n"))
 
@@ -485,7 +488,7 @@ Returns what was actually sent, or nil if nothing was sent."
 	    (if moving
 		(goto-char target))))))
 
-   ((processp target)
+   ((eshell-processp target)
     (when (eq (process-status target) 'run)
       (setq object (eshell-stringify object))
       (process-send-string target object)))
diff --git a/lisp/eshell/esh-mode.el b/lisp/eshell/esh-mode.el
index 0bb07734c14..2db4f2a10b6 100644
--- a/lisp/eshell/esh-mode.el
+++ b/lisp/eshell/esh-mode.el
@@ -474,6 +474,7 @@ sessions, such as when using `eshell-command'.")
 (defun eshell-find-tag (&optional tagname next-p regexp-p)
   "A special version of `find-tag' that ignores read-onlyness."
   (interactive)
+  (require 'etags)
   (let ((inhibit-read-only t)
 	(no-default (eobp)))
     (setq tagname (find-tag-interactive "Find tag: " no-default))
diff --git a/lisp/eshell/esh-proc.el b/lisp/eshell/esh-proc.el
index ead49e1942f..ddb2c986a96 100644
--- a/lisp/eshell/esh-proc.el
+++ b/lisp/eshell/esh-proc.el
@@ -125,14 +125,15 @@ information, for example."
   "Reset the command input location after a process terminates.
 The signals which will cause this to happen are matched by
 `eshell-reset-signals'."
-  (if (string-match eshell-reset-signals status)
+  (if (and (stringp status)
+	   (string-match eshell-reset-signals status))
       (eshell-reset)))
 
 (defun eshell-wait-for-process (&rest procs)
   "Wait until PROC has successfully completed."
   (while procs
     (let ((proc (car procs)))
-      (when (processp proc)
+      (when (eshell-processp proc)
 	;; NYI: If the process gets stopped here, that's bad.
 	(while (assq proc eshell-process-list)
 	  (if (input-pending-p)
@@ -145,7 +146,8 @@ The signals which will cause this to happen are matched by
 
 (defun eshell/jobs (&rest args)
   "List processes, if there are any."
-  (and (process-list)
+  (and (fboundp 'process-list)
+       (process-list)
        (list-processes)))
 
 (defun eshell/kill (&rest args)
@@ -153,7 +155,7 @@ The signals which will cause this to happen are matched by
   (let ((ptr args)
 	(signum 'SIGINT))
     (while ptr
-      (if (or (processp (car ptr))
+      (if (or (eshell-processp (car ptr))
 	      (and (stringp (car ptr))
 		   (string-match "^[A-Za-z/][A-Za-z0-9<>/]+$"
 				 (car ptr))))
@@ -162,7 +164,7 @@ The signals which will cause this to happen are matched by
 	  (setcar ptr (get-process (car ptr))))
       (setq ptr (cdr ptr)))
     (while args
-      (let ((id (if (processp (car args))
+      (let ((id (if (eshell-processp (car args))
 		    (process-id (car args))
 		  (car args))))
 	(when id
@@ -206,7 +208,7 @@ The prompt will be set to PROMPT."
 
 (defsubst eshell-record-process-object (object)
   "Record OBJECT as now running."
-  (if (and (processp object)
+  (if (and (eshell-processp object)
 	   eshell-current-subjob-p)
       (eshell-interactive-print
        (format "[%s] %d\n" (process-name object) (process-id object))))
@@ -217,7 +219,7 @@ The prompt will be set to PROMPT."
 
 (defun eshell-remove-process-entry (entry)
   "Record the process ENTRY as fully completed."
-  (if (and (processp (car entry))
+  (if (and (eshell-processp (car entry))
 	   (nth 2 entry)
 	   eshell-done-messages-in-minibuffer)
       (message (format "[%s]+ Done %s" (process-name (car entry))
@@ -225,6 +227,12 @@ The prompt will be set to PROMPT."
   (setq eshell-process-list
 	(delq entry eshell-process-list)))
 
+(defvar eshell-scratch-buffer " *eshell-scratch*"
+  "Scratch buffer for holding Eshell's input/output.")
+(defvar eshell-last-sync-output-start nil
+  "A marker that tracks the beginning of output of the last subprocess.
+Used only on systems which do not support async subprocesses.")
+
 (defun eshell-gather-process-output (command args)
   "Gather the output from COMMAND + ARGS."
   (unless (and (file-executable-p command)
@@ -235,39 +243,88 @@ The prompt will be set to PROMPT."
 	      eshell-delete-exited-processes
 	    delete-exited-processes))
 	 (process-environment (eshell-environment-variables))
-	 (proc (apply 'start-process
-		      (file-name-nondirectory command) nil
-		      ;; `start-process' can't deal with relative
-		      ;; filenames
-		      (append (list (expand-file-name command)) args)))
-	 decoding encoding changed)
-    (eshell-record-process-object proc)
-    (set-process-buffer proc (current-buffer))
-    (if (eshell-interactive-output-p)
-	(set-process-filter proc 'eshell-output-filter)
-      (set-process-filter proc 'eshell-insertion-filter))
-    (set-process-sentinel proc 'eshell-sentinel)
-    (run-hook-with-args 'eshell-exec-hook proc)
-    (when (fboundp 'process-coding-system)
-      (let ((coding-systems (process-coding-system proc)))
-	(setq decoding (car coding-systems)
-	      encoding (cdr coding-systems)))
-      ;; If start-process decided to use some coding system for
-      ;; decoding data sent from the process and the coding system
-      ;; doesn't specify EOL conversion, we had better convert CRLF
-      ;; to LF.
-      (if (vectorp (coding-system-eol-type decoding))
-	  (setq decoding (coding-system-change-eol-conversion decoding 'dos)
-		changed t))
-      ;; Even if start-process left the coding system for encoding
-      ;; data sent from the process undecided, we had better use the
-      ;; same one as what we use for decoding.  But, we should
-      ;; suppress EOL conversion.
-      (if (and decoding (not encoding))
-	  (setq encoding (coding-system-change-eol-conversion decoding 'unix)
-		changed t))
-      (if changed
-	  (set-process-coding-system proc decoding encoding)))
+	 proc decoding encoding changed)
+    (cond
+     ((fboundp 'start-process)
+      (setq proc
+	    (apply 'start-process
+		   (file-name-nondirectory command) nil
+		   ;; `start-process' can't deal with relative
+		   ;; filenames
+		   (append (list (expand-file-name command)) args)))
+      (eshell-record-process-object proc)
+      (set-process-buffer proc (current-buffer))
+      (if (eshell-interactive-output-p)
+	  (set-process-filter proc 'eshell-output-filter)
+	(set-process-filter proc 'eshell-insertion-filter))
+      (set-process-sentinel proc 'eshell-sentinel)
+      (run-hook-with-args 'eshell-exec-hook proc)
+      (when (fboundp 'process-coding-system)
+	(let ((coding-systems (process-coding-system proc)))
+	  (setq decoding (car coding-systems)
+		encoding (cdr coding-systems)))
+	;; If start-process decided to use some coding system for
+	;; decoding data sent from the process and the coding system
+	;; doesn't specify EOL conversion, we had better convert CRLF
+	;; to LF.
+	(if (vectorp (coding-system-eol-type decoding))
+	    (setq decoding (coding-system-change-eol-conversion decoding 'dos)
+		  changed t))
+	;; Even if start-process left the coding system for encoding
+	;; data sent from the process undecided, we had better use the
+	;; same one as what we use for decoding.  But, we should
+	;; suppress EOL conversion.
+	(if (and decoding (not encoding))
+	    (setq encoding (coding-system-change-eol-conversion decoding 'unix)
+		  changed t))
+	(if changed
+	    (set-process-coding-system proc decoding encoding))))
+     (t
+      ;; No async subprocesses...
+      (let ((oldbuf (current-buffer))
+	    (interact-p (eshell-interactive-output-p))
+	    lbeg lend line proc-buf exit-status)
+	(and (not (markerp eshell-last-sync-output-start))
+	     (setq eshell-last-sync-output-start (point-marker)))
+	(setq proc-buf
+	      (set-buffer (get-buffer-create eshell-scratch-buffer)))
+	(erase-buffer)
+	(set-buffer oldbuf)
+	(run-hook-with-args 'eshell-exec-hook command)
+	(setq exit-status
+	      (apply 'call-process-region
+		     (append (list eshell-last-sync-output-start (point)
+				   command t
+				   eshell-scratch-buffer nil)
+			     args)))
+	;; When in a pipeline, record the place where the output of
+	;; this process will begin.
+	(and eshell-in-pipeline-p
+	     (set-marker eshell-last-sync-output-start (point)))
+	;; Simulate the effect of the process filter.
+	(when (numberp exit-status)
+	  (set-buffer proc-buf)
+	  (goto-char (point-min))
+	  (setq lbeg (point))
+	  (while (eq 0 (forward-line 1))
+	    (setq lend (point)
+		  line (buffer-substring-no-properties lbeg lend))
+	    (set-buffer oldbuf)
+	    (if interact-p
+		(eshell-output-filter nil line)
+	      (eshell-output-object line))
+	    (setq lbeg lend)
+	    (set-buffer proc-buf))
+	  (set-buffer oldbuf))
+	(eshell-update-markers eshell-last-output-end)
+	;; Simulate the effect of eshell-sentinel.
+	(eshell-close-handles (if (numberp exit-status) exit-status -1))
+	(run-hook-with-args 'eshell-kill-hook command exit-status)
+	(or eshell-in-pipeline-p
+	    (setq eshell-last-sync-output-start nil))
+	(if (not (numberp exit-status))
+	  (error "%s: external command failed: %s" command exit-status))
+	(setq proc t))))
     proc))
 
 (defun eshell-insertion-filter (proc string)
diff --git a/lisp/eshell/esh-util.el b/lisp/eshell/esh-util.el
index de19b636100..3d650928c62 100644
--- a/lisp/eshell/esh-util.el
+++ b/lisp/eshell/esh-util.el
@@ -262,7 +262,7 @@ If N or M is nil, it means the end of the list."
 
 (put 'eshell-for 'lisp-indent-function 2)
 
-(defsubst eshell-flatten-list (args)
+(defun eshell-flatten-list (args)
   "Flatten any lists within ARGS, so that there are no sublists."
   (let ((new-list (list t)))
     (eshell-for a args
diff --git a/lisp/eshell/esh-var.el b/lisp/eshell/esh-var.el
index 133239703b6..34994630251 100644
--- a/lisp/eshell/esh-var.el
+++ b/lisp/eshell/esh-var.el
@@ -264,7 +264,7 @@ function), and the arguments passed to this function would be the list
   "Parse a variable interpolation.
 This function is explicit for adding to `eshell-parse-argument-hook'."
   (when (and (eq (char-after) ?$)
-	     (not (= (1+ (point)) (point-max))))
+	     (/= (1+ (point)) (point-max)))
     (forward-char)
     (list 'eshell-escape-arg
 	  (eshell-parse-variable))))
@@ -293,11 +293,19 @@ This function is explicit for adding to `eshell-parse-argument-hook'."
 (defun eshell/export (&rest sets)
   "This alias allows the 'export' command to act as bash users expect."
   (while sets
-    (if (string-match "^\\([^=]+\\)=\\(.*\\)" (car sets))
+    (if (and (stringp (car sets))
+	     (string-match "^\\([^=]+\\)=\\(.*\\)" (car sets)))
 	(setenv (match-string 1 (car sets))
 		(match-string 2 (car sets))))
     (setq sets (cdr sets))))
 
+(defun eshell/unset (&rest args)
+  "Unset an environment variable."
+  (while args
+    (if (stringp (car args))
+	(setenv (car args) nil t))
+    (setq args (cdr args))))
+
 (defun pcomplete/eshell-mode/export ()
   "Completion function for Eshell's `export'."
   (while (pcomplete-here
diff --git a/lisp/pcmpl-gnu.el b/lisp/pcmpl-gnu.el
index f390f541e25..f7a681c803e 100644
--- a/lisp/pcmpl-gnu.el
+++ b/lisp/pcmpl-gnu.el
@@ -33,7 +33,7 @@
 ;; User Variables:
 
 (defcustom pcmpl-gnu-makefile-regexps
-  '("\\`Makefile\\." "\\.mak\\'")
+  '("\\`GNUmakefile" "\\`Makefile" "\\.mak\\'")
   "*A list of regexps that will match Makefile names."
   :type '(repeat regexp)
   :group 'pcmpl-gnu)
@@ -111,7 +111,10 @@
 (defun pcmpl-gnu-make-rule-names ()
   "Return a list of possible make rule names in MAKEFILE."
   (let* ((minus-f (member "-f" pcomplete-args))
-	 (makefile (or (cadr minus-f) "Makefile"))
+	 (makefile (or (cadr minus-f)
+		       (if (file-exists-p "GNUmakefile")
+			   "GNUmakefile"
+			 "Makefile")))
 	 rules)
     (if (not (file-readable-p makefile))
 	(unless minus-f (list "-f"))
diff --git a/lisp/pcomplete.el b/lisp/pcomplete.el
index 2b66b1d45b9..4f506212230 100644
--- a/lisp/pcomplete.el
+++ b/lisp/pcomplete.el
@@ -303,6 +303,14 @@ This function is used to generate completions for every argument."
   :type 'function
   :group 'pcomplete)
 
+(defcustom pcomplete-use-paring t
+  "*If t, pare alternatives that have already been used.
+If nil, you will always see the completion set of possible options, no
+matter which of those options have already been used in previous
+command arguments."
+  :type 'boolean
+  :group 'pcomplete)
+
 ;;; Internal Variables:
 
 ;; for cycling completion support
@@ -1017,7 +1025,7 @@ extra checking, and munging of the COMPLETIONS list."
 	   (message "No completions of %s" stub)
 	 (message "No completions")))
     ;; pare it down, if applicable
-    (if pcomplete-seen
+    (if (and pcomplete-use-paring pcomplete-seen)
 	(let* ((arg (pcomplete-arg))
 	       (prefix
 		(file-name-as-directory