[O] empty titles - backtrace

[Richard Riley]

Is not too rare for me to accidentally wipe or neglect to add a subject
line to a new journal/or entry. Of course I should have one - bUt
regardless, generating the agenda shouldnt fail if it comes across an
entry with no title as it can be hard to find the offending org
item. e.g

,----
| Debugger entered--Lisp error: (wrong-type-argument stringp nil)
|   string-match("^ +" nil)
|   org-format-agenda-item(nil nil #("Journal" 0 7 (fontified t org-category 
"Journal" face org-meta-line font-lock-fontified t)) (#("journal" 0 7 
(inherited t))) #("<2011-04-13 Mi 10:00>" 0 20 (org-category #("Journal" 0 7 
...) keymap (keymap ... ... ...) mouse-face highlight org-no-flyspell t face 
org-date fontified t) 20 21 (org-category #("Journal" 0 7 ...) rear-nonsticky 
(mouse-face highlight keymap invisible intangible help-echo org-linked-text) 
keymap (keymap ... ... ...) mouse-face highlight org-no-flyspell t face 
org-date fontified t)) "<2011-04-13.*?>")
|   byte-code("\306 \203\n.\307\310\311\"\210\312 
\210\313\225\203$.\314\315\313!\311 
$U\204$.\307\310\311\"\210\n\2037.\316\n{\317\f#\2047.\307\310\311\"\210e.)Z].{.*\203I.\317\202M.
\320 
{.+.f\321U.,\322.-.*\"..\322./.*\".0.1\205p.\322.2.*\".3.1\205\205.\322.4.*\"\206\205.\322\323.*\".5.%.6\235.7.0\204\254..\204\254.3\204\254.5\204\254.7\203\261.8\203\261.\307\310\324\"\210\322\325.+\"\203\301.+\326\211\225O.+\327.!.9\330.!.:\212\331\332\311\324#\204\333.;.<\202.
\326\224b\210\327
 .=\333 
.>\334\335!\210\315\313!.?\336.,address@hidden:.>.+.A&.<\337.<!.#\340.<.B\341.9\342.=&.\210\340.<\311\343.#\344.:\304\f\345.%\346\347&\f\210.<.CB.C).D\203A.\350
 \210\202E.Eb\210\311\207" [d1 show-all e3 b3 date b0 org-at-date-range-p 
throw :skip nil org-agenda-skip 1 org-time-string-to-absolute match-string 
org-diary-sexp-entry "" point-at-eol 91 string-match "]-+\\'" t ">" 0 
org-agenda-new-marker org-get-category re-search-backward "^\\*+ " 
org-get-tags-at looking-at "\\*+[         ]+\\([^.\n]+\\)" 
org-format-agenda-item org-get-priority org-add-props org-marker org-hd-marker 
priority org-category todo-state type "timestamp" outline-next-heading 
org-ds-keyword-length tmp timestr inactivep org-deadline-regexp deadlinep 
org-scheduled-regexp scheduledp org-agenda-include-inactive-timestamps ...] 13)
|   org-agenda-get-timestamps()
`----

Where the item in question was:

,----
| **** 
|         :PROPERTIES:
|         :DateCreated: <2011-04-13 Mi 10:00>
|         :END:
| 
| 
[[gnus:nntp%2BGwene:gwene.org.emacsen.planet][gnus:nntp+Gwene:gwene.org.emacsen.planet]]
`----

a nilstring check in org-format-agenda-item isnt enough.

So, is there a way to enforce a default value "org wide" subject if the user
accidentally deletes or doesnt enter an org subject?