Why not erase most* files before uploading v7 code?

Adding to my prior post...

I just found another case in which deleting existing "old version" files might be a good idea. On my brand-new 7.0.5 site I was exploring my profile setting. What's my default theme? Hmmm, the list offered included Aztec, the original site default (I guess) when it was running 6.00.300. That theme is no longer supported, right? Why is it being offered to me here? Will it work? Try it...

D'oh! This 7.0.5 installation is completely broken now. All it will return is


Fatal error: Cannot redeclare opensidex() (previously declared in /home1/aaaa/public_html/bbbb/themes/Aztec/theme.php:164) in /home1/aaaaa/public_html/bbbb/includes/theme_functions_include.php on line 196

no matter what step in the history I try returning to. I imagine I can repair it by mucking around directly in the DB and changing my profile manually so that it no longer specifies this invalid theme.

I mentioned earlier that my predecessor apparently installed an infusion by direct DB modification. Could he have similarly welded the Aztec theme into the site similarly? If so, I'm clearly going to need to do some cutting in the DB, but in the meantime wouldn't I be better off deleting all the old v6 themes before installing the v7 themes?

Hmmm, I fixed the site by changing /themes/Aztec to /themes/foo. That seems to indicate that the code does much better with a theme that cannot be found -- it returns to using the default, and that's what my profile shows now. That's a lot better than throwing a fatal error.

How frequent is this kind of issue in your experience?

Henry

thanks for your sharing.........

You've got a point there.
One reason for NOT making a cleanup prior to uploading all the v7 files could be if you have special own-developed files somewhere.
But if you know them and where they are (hopefuly you do!) then it sure makes sense to clean the root out before uploading.

What I did a couple of times was to rename the existing directories; then upload; test, and then delete the renamed directories.
But you have to be careful, of course :)

Yxos:

Thanks for your response.

Yes, there's always a problem with privately-developed files.. and mods to standard ones, which may or may not be applicable in the new version. It's a very difficult problem. I think a clean-up script that generates a second script of proposed deletions _might_ be helpful in many cases. But I have no idea how frequently and extensively people modify the standard file sets of a given version. If the answer is "often" and "a lot", then .. .never mind.

Follow-up question:

Suppose you find a file ("xyzzy.php") in your current installation that you think is never used. How can you find out if it is, besides renaming it ("qqqxyzzy.php") and fooling around with your site for a while to see if get an error message? The file in question may be referenced in other files, so a site-wide source-code search for "xyzzy.php" should find it. (Or without the extension, only "xyzzy"?) But is it possible/customary/likely that the reference is embedded only in the database? If so, how would you find it? (I don't know much about phpMyAdmin. Does it have a global string search?)

Note: I think this is still reasonably on-topic; it's about cleaning up and moving forward to the new version.

Thanks,

Henry

fantastic, keep up the good work!

i am the one from the ppl who...well...can answer often and a lot ^^. In fact, i understand your opinion and i found too some files extra, if i can say like that, and deleted them. But for sure i can't do a total erase a v6 then install v7 exactly for the reason above..You have right in some way, but it is like yxos said.