bug#3375: FW: Fix "Document incompatible change to format of bookmarks"

[Drew Adams]

Forgot to send to the bug thread. I keep forgetting that cc'ing the close
message doesn't copy the actual bug thread.

-----Original Message-----
From: Drew Adams Sent: Thursday, October 08, 2009 11:18 PM
To: 'Karl Fogel'; '3375-close@emacsbugs.donarmstrong.com'
Subject: RE: Fix "Document incompatible change to format of bookmarks"

> Thanks for the report.  I've documented the format change in NEWS;...
> 
> (I don't know why the default write-out format was changed, 
> as I didn't commit rev 1.114 of bookmark.el.  We could investigate
> and find out, but it would be of forensic interest only at this
> point -- the change is made, and there's a long list of
> bookmark.el bugs to go.  So I'm not going to investigate the
> reasoning behind 1.114 closely; if you happen to find out,
> please let me know.)


Thanks for adding the NEWS entry, Karl.

It's really too bad that this incompatible change was made without anyone
documenting the reason (at least I haven't found such documentation). Likewise,
without any discussion (that I'm aware of).

One can only hope that the change was truly necessary or at least somehow
useful, for whatever unknown reason.

The 1.114 log entry seems to suggest that it only adjusted some parts of the
code to work with "the 2 slightly different formats used until now in
bookmark.el's code."

It's unclear what that text really tries to mean, but if it is suggesting that
the new, Emacs 23 format was already in use in (some parts of) the bookmark
code, then that's not true (assuming that you're right that 1.114 is the
culprit, which it does seem to be).

This is an incompatible change in the basic bookmark format, starting with Emacs
23 (apparently, starting with 1.114). It seems to be a gratuitous change, but
how to tell, since no reason was given?

I wonder if, in making that change, Stefan was aware that the format is new, or
if he perhaps really thought that it had been in use previously. Perhaps he was
confused by the misleading (incorrect) comments in the file. Dunno. And we'll
likely never know, as you point out. Too bad.

We've now had at least two incompatible format changes to the `bookmark-alist'
structure, over its history. Neither of which brought anything useful to the
party, AFAICT. Oh well. Let's hope that next year someone doesn't mutate the
structure to a fourth format. ;-)

Thx - Drew