Fix error in :WikiPageRename

[digital-carver]

Trying to run :WikiPageRename asks the confirmation prompt and then the new name, but errors out after that:

Error detected while processing function wiki#page#rename_ask[11]..wiki#page#rename:
line   64:
E119: Not enough arguments for function: bufnr
E15: Invalid expression: bufnr()
Press ENTER or type command to continue

I believe the problem is the empty call to bufnr() at lines 102 and 118 of autoload/wiki/page.vim. Changing those to bufnr('') (like in scratch.vim) fixes the issue.

[lervag]

I'm curious; which version of Vim are you on? On my end, this fix is not necessary. I use Vim 8.2 and neovim 0.5.

[lervag]

I'm merging as I don't see a reason why not, but I'm still curious :)

[digital-carver]

I'm curious; which version of Vim are you on? On my end, this fix is not necessary. I use Vim 8.2 and neovim 0.5.

Ah, I did not realize it was a version-dependent issue. I was on Vim 8.0.1568, which seems to be the latest version in my distro's official repository. I've found a different repo with more recent updates though, and am updating to Vim 8.2 right now. Thanks for indulging your curiosity and prompting this update. :)

[lervag]

I guess there's been a change to the bufnr() function since Vim 8.0, then. And no problem; I usually recommend people to try and use the latest versions of Vim (or neovim). Updates are usually improvements.