Wikibooks:History merging

History merging is a procedure where the histories of two pages are spliced together, usually for the sake of fixing a "cut-and-paste move".

Cut-and-paste moves

Sometimes, editors who are less experienced, or who are not yet autoconfirmed, will attempt to rename a page by copy-and-pasting its contents to a different title. All autoconfirmed users can rename a page directly by using Special:MovePage, which is preferred since it preserves attribution, which is necessary under Wikibooks's licensing terms. Firstly, the GNU Free Documentation License requires that we:

Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page.

Similarly, the Creative Commons Attribution-ShareAlike 4.0 International License requires us to:

... [R]etain... identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated).

Cut-and-paste transwikis

Before Special:Import was enabled on the English Wikibooks, it was common practice to copy-and-paste pages directly from other wikis (usually the English Wikipedia), and leave a wikitext version of the page's history on the talk page (this is called an "unmerged transwiki"). This method is discouraged, unless the content being copied to Wikibooks is a small portion of the source page.

Example

An example of a cut-and-paste move can be seen /Example target. This page was cut-and-pasted from /Example source by a different user without attribution. This problem can be solved by history merging.

History merging

To perform a history merge, you can use the Special:MergeHistory page. Note that only administrators, importers, and import uploaders can use this tool.

On the page, you will find two text boxes, one for the source page, and one for the target page. The source page field should contain the page that was cut-and-pasted, and the target page should contain the page that the source page's contents were copied to. Then, click the "Show mergeable edits" button. Select the last edit you want to merge, add a reason, and click "Merge revisions".

A common pitfall

Some new history-mergers are confused when they see that not all page revisions appear in "Show mergeable edits". This is because the MediaWiki software does not allow you to merge revisions that are newer than the first revision on the target page.