Help:Edit conflict
In certain situations, two people may try to edit the same page at the same time. If this happens, the second person to attempt to save the page will cause an edit conflict — that is, a conflict between two different saved versions of the same page. Consider the following sequence of events:
- Adam clicks the "edit this page" button, and begins editing an article.
- Eve clicks the "edit this page" button, and begins editing the same article.
- Adam saves his version of the article.
- Eve tries to save her version of the article, which is different from Adam's version.
In cases such as these, several things can happen. First, the MediaWiki software will attempt to merge the two versions of the page. Using the diff3 utility, MediaWiki can combine the two versions of the page — provided that Adam and Eve each changed different parts of the article. However, Adam and Eve might have made different changes to the same part of the article. The rest of this page will address the second situation.
Conflict warning page
If MediaWiki cannot merge the two versions of the page on its own, it will bring up a "conflict warning" notice when Eve tries to save her version of the article, because Adam has already saved his version. The conflict warning notice contains three parts: first, at the top is shown Adam's version of the page. At the bottom, the version that Eve was trying to submit is shown. In the middle, a colored table shows the differences between the two versions.
How to resolve a conflict
Resolving an edit conflict is always a value judgment. Eve must choose whether to integrate her changes with Adam's version, or Adam's changes with her version. In either case, she can then add some text like "via edit conflict" in the edit summary to warn others that she had to integrate the changes.
If both Adam and Eve made large changes to the article, the situation is more complicated. Sometimes, it may just be best to temporarily add both versions of the text, and to merge them later on after some discussion on the article's talk page.
In all cases, Eve should never simply post her own changes on top of Adam's. Such an act is unfair to Adam because it erases the work he just completed, and is therefore considered bad etiquette.
"In use" message
For convenience, OpenVistA Wiki includes the option of posting an "in use" message at the top of a page. Simply paste the string {{inuse}} at the top of the wikitext and save the page; this will inform people who come after you that you are in the process of editing the page, and help to avoid edit conflicts. (This should generally only be used for large edits, however.)
