Ticking "Include all templates and transcluded pages" when doing an import should require some kind of confirmation. People have done this accidentally from time to time (most recently https://en.wikipedia.org/wiki/Wikipedia:Administrators%27_noticeboard/Archive361#Cleanup_for_an_import_booboo), and it is a complete pain to undo.
Ideally it would list the pages you are going to import, and say "are you sure you want to import these pages" before continuing.
Description from duplicate T387455: It is way too easy to overwrite existing pages (and merging edit histories) by doing a transwiki import
On no.wikipedia (nowiki), User:1000mm imported the page "Peder Andersen" from nnwiki. When importing, they checked the "Include all templates and transcluded pages" checkbox.
The result was that 39 other pages were also imported; many (maybe even most?) of these already existed as pages in nowiki, and now their histories are a merry mix of nowiki and nnwiki history, which would be super time-consuming to untangle.
Steps to replicate the issue (include links if applicable):
- Have transwiki importer rights on no.wikipedia.org
- Go to Special:Import
- Import the page "Brukar:Jon Harald Søby/Test" from nn (nn.wikipedia.org)
- Check the "Include all templates" checkbox
What happens?:
- With no intermediate confirmation step, the page is imported, as is the page that is transcluded on it (nn:Brukar:Jon Harald Søby/test3), even though a page with that title already exists
- The page history of no:Bruker:Jon Harald Søby/test3 becomes a mix of revisions already existinfg on nowiki, and revisions imported from nnwiki
What should have happened instead?:
At the very least, there should be an intermediate step after pressing "import", letting the user know which pages will actually be imported if they proceed, and letting them know which of those pages already exist and will have their histories messed up by this import.