If you just want to show a thumbnail of an attachment in a public logbook, then just add a link to it. like

<img src="https://abk.web.psi.ch/tmp/t.png" alt="" />

or in your example you show the thumbnail in the hidden logbook by adding in the text body:

<img src="<your-host-url>/public/110705_235520_whatthis-0.png" alt="" />

Of course the attachment has to be in the public logbook and the link in the hidden one.

> I wondered if there had been some flag for the config file whereby the original file for attachment was
> processed by ImageMagick, but not stored, only the .png file(s) stored - or rather, some other way that achieved
> the same end. as there is no such flag at present.
> 
> For now, anyway, I can attach the documents/pics I want, then go in and delete the 'originals' as saved in the
> logbook, leaving just the .png files. But maybe something for the wishlist?

At least I now understood your problem :-)

You can have a script in your hidden logbook, that processes your attachments with "execute new", create thumbnails
of them (using ImageMagicks "convert") and submit those thumbnails as one additional entry to your public logbook.

But then you would get thumbnails of all attachments of the hidden logbook in the public one, maybe you don't want
that either? If you want them all, this method is more automated. If you just want some, do it as you suggested it.

In my opinion this is a rather exotic feature request :-)
I wonder if there is a second person in the world who could use it?

You will not loose your logbook data if you have access rights to the file system where the "elogd" program writes it's data.

The easiest way is to edit there password file directly and then restart "elogd".

But even if you do not dare to edit the files directly, you still can solve the issue from the web interface:

• Create a new account, e.g. user "admin2"
• While logged in as "admin", make this user an administrator: go to "Change config file", add "Admin user = admin, admin2"
• Now log off and then login as "admin2"
• Check that you can do administration, then remove user "admin"
• Create a new user "admin" with proper "Full name" and "Email"
• Now log off and then login as "admin"
• Check that you can do administration, then remove user "admin2"

That should work. Good luck!

Some user wanted to modify the URL by hand and succeeded to crash the elogd process with npp=now
It appears that npp=0 crashes elogd with the following error message:

Program received signal SIGFPE, Arithmetic exception.
0x0808eba2 in show_elog_list (lbs=0xab3c770, past_n=0, last_n=0, page_n=1,
    default_page=1, info=0x0) at src/elogd.c:20214
20214            sprintf(str + strlen(str), loc("Page %d of %d"), page_n, (n_msg - 1) / n_page + 1);

I guess this bug is not OS dependent: you can crash every logbook that you can search ;-)

> [...] It appears that npp=0 crashes elogd [...]

Here's a patch: search for "npp" in src/elogd.c and add the following line:
  if (n_page<=0) n_page = 20;

Here's the diff output for version 2.9.0-2414
*** 20092,20096 ****
     if (isparam("npp"))
        n_page = atoi(getparam("npp"));
+    if (n_page<=0) n_page = 20;

     if (page_mid) {

A query to a logbook can crash the demon.

Query:
https://pc8059.psi.ch:444/SwissFEL+Injector/?jcmd=Find&m0a=10&d0a=27&y0a=2011&npp=1&reverse=0

gdb dump:
SSLServer listening on port 444 ...

Program received signal SIGSEGV, Segmentation fault.
show_elog_list (lbs=0xae72618, past_n=0, last_n=0, page_n=0, default_page=1, info=0x0) at src/elogd.c:20797
20797         message_id = msg_list[index].lbs->el_index[msg_list[index].index].message_id;

If you use an attribute "Entry" then the internal variable "entry time" will expand to the last value of
"$Entry"+" time", e.g. if you use it in "Thread display = $entry time, ..."

One side effect is, that the logbook selection page defaults to use
Last submission = $entry time by $author
Which then expands to an undesired result.

This is not really a bug, rather something you'll need to keep in the back of your mind.