Clock: Fix bugs when resuming the clock.

Adam Elliot writes:

>  Automatically resuming the clock after an Emacs restart
>  fails under the following cases:
>
>  1. If org-log-states-order-reversed set to t (default), and
>     a state change line precedes the clock line to resume.
>     Error message is "Cannot restart clock because task does
>     not contain unfinished clock".
>
[...]
>  2. If org-log-states-order-reversed set to nil.  Error
>     message is the same.  Reason: point is placed *after*
>     last clock line and so fails looking-at test.
>

This commit fixes the problem, in a slightly different way
than Adam proposed.  Instead of trying to fix the old way to
find the position of the clock, we now simple search the
entry if there is an unfinished clock and go there.  Since
new clocks are added before older ones, this should be a
safe bet.

lisp/ChangeLog

@@ -1,3 +1,12 @@
+2009-04-14  Carsten Dominik  <carsten.dominik@gmail.com>
+
+	* org-clock.el: Fix a number of docstrings.
+	(org-clock-find-position): New argument
+	FIND-UNCLOSED to make the function find an unclosed clock in the
+	entry.
+	(org-clock-in): Call `org-clock-find-position' with the new
+	argument if we might be resuming a clock.
+
 2009-04-13  Carsten Dominik  <carsten.dominik@gmail.com>
 
 	* org-latex.el (org-export-latex-display-custom-times): New variable.

lisp/org-clock.el

@@ -62,7 +62,7 @@ which see."
 	  (string :tag "Into Drawer named...")))
 
 (defcustom org-clock-out-when-done t
-  "When non-nil, the clock will be stopped when the relevant entry is marked DONE.
+  "When non-nil, clock will be stopped when the clocked entry is marked DONE.
 A nil value means, clock will keep running until stopped explicitly with
 `C-c C-x C-o', or until the clock is started in a different item."
   :group 'org-clock
@@ -99,26 +99,28 @@ The function is called with point at the beginning of the headline."
   :type 'function)
 
 (defcustom org-clock-string-limit 0
-  "Maximum length of clock strings in the modeline. 0 means no limit"
+  "Maximum length of clock strings in the modeline. 0 means no limit."
   :group 'org-clock
   :type 'integer)
 
 (defcustom org-clock-in-resume nil
-  "If non-nil, when clocking into a task with a clock entry which
-has not been closed, resume the clock from that point"
+  "If non-nil, resume clock when clocking into task with open clock.
+When clocking into a task with a clock entry which has not been closed,
+the clock can be resumed from that point."
   :group 'org-clock
   :type 'boolean)
 
 (defcustom org-clock-persist nil
-  "When non-nil, save the running clock when emacs is closed, and
-  resume it next time emacs is started.
+  "When non-nil, save the running clock when emacs is closed.
+The clock is resumed when emacs restarts.
 When this is t, both the running clock, and the entire clock
 history are saved.  When this is the symbol `clock', only the
 running clock is saved.
 
 When Emacs restarts with saved clock information, the file containing the
 running clock as well as all files mentioned in the clock history will
-be visited."
+be visited.
+All this depends on running `org-clock-persistence-insinuate' in .emacs"
   :group 'org-clock
   :type '(choice
 	  (const :tag "Just the running clock" clock)
@@ -127,18 +129,17 @@ be visited."
 
 (defcustom org-clock-persist-file (convert-standard-filename
 				   "~/.emacs.d/org-clock-save.el")
-  "File to save clock data to"
+  "File to save clock data to."
   :group 'org-clock
   :type 'string)
 
 (defcustom org-clock-persist-query-save nil
-  "When non-nil, ask before saving the current clock on exit"
+  "When non-nil, ask before saving the current clock on exit."
   :group 'org-clock
   :type 'boolean)
 
 (defcustom org-clock-persist-query-resume t
-  "When non-nil, ask before resuming any stored clock during
-load."
+  "When non-nil, ask before resuming any stored clock during load."
   :group 'org-clock
   :type 'boolean)
 
@@ -339,11 +340,11 @@ the clocking selection, associated with the letter `d'."
 			(t "???")))
 	    (setq org-clock-heading (org-propertize org-clock-heading
 						    'face nil))
-	    (org-clock-find-position)
+	    (org-clock-find-position org-clock-in-resume))
 	    (cond
 	     ((and org-clock-in-resume
 		   (looking-at
-		    (concat "^[ \\t]* " org-clock-string
+		    (concat "^[ \t]* " org-clock-string
 			    " \\[\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}"
 			    " +\\sw+ +[012][0-9]:[0-5][0-9]\\)\\][ \t]*$")))
 	      (message "Matched %s" (match-string 1))
@@ -381,8 +382,10 @@ the clocking selection, associated with the letter `d'."
 		  (run-with-timer 60 60 'org-clock-update-mode-line))
 	    (message "Clock started at %s" ts)))))))
 
-(defun org-clock-find-position ()
-  "Find the location where the next clock line should be inserted."
+(defun org-clock-find-position (find-unclosed)
+  "Find the location where the next clock line should be inserted.
+When FIND-UNCLOSED is non-nil, first check if there is an unclosed clock
+line and position cursor in that line."
   (org-back-to-heading t)
   (catch 'exit
     (let ((beg (save-excursion
@@ -396,6 +399,14 @@ the clocking selection, associated with the letter `d'."
 		      org-clock-into-drawer "LOGBOOK"))
 	  first last ind-last)
       (goto-char beg)
+      (when (and find-unclosed
+		 (re-search-forward
+		  (concat "^[ \t]* " org-clock-string
+			  " \\[\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}"
+			  " +\\sw+ +[012][0-9]:[0-5][0-9]\\)\\][ \t]*$")
+		  end t))
+	(beginning-of-line 1)
+	(throw 'exit t))		 
       (when (eobp) (newline) (setq end (max (point) end)))
       (when (re-search-forward (concat "^[ \t]*:" drawer ":") end t)
 	;; we seem to have a CLOCK drawer, so go there.
@@ -1172,8 +1183,7 @@ The details of what will be saved are regulated by the variable
   "Was the clock file loaded?")
 
 (defun org-clock-load ()
-  "Load various clock-related data from disk, optionally resuming
-a stored clock"
+  "Load clock-related data from disk, maybe resuming a stored clock."
   (when (and org-clock-persist (not org-clock-loaded))
     (let ((filename (expand-file-name org-clock-persist-file))
 	  (org-clock-in-resume 'auto-restart)