The conflicts testcase has 4 failing test cases. The underlaying problem is that there are multiple possible source files that can create the same destination files.

1. foo.mdwn is in srcdir, rendered to destdir. Then it is removed, and foo is added, which will be rendered raw to destdir. Since the foo/ directory still exists, it fails.
2. foo is added to srcdir, rendered raw to destdir. Then it is removed from srcdir, and foo.mdwn is added. The foo file is still present in the destdir, and mkdir of the directory foo/ fails.
3. foo.mdwn renders to foo/index.html. Then foo/index.html is added to the srcdir, using rawhtml. It renders to the same thing.
4. foo/index.html in srcdir is rendered to same thing in destdir using rawhtml. Then foo.mdwn is added; renders same thing.

Note that another case, that of page foo.mdwn and page foo.txt, that both render to foo/index.html, used to cause problems, but no longer crashes ikiwiki. It now only complains in this situation, and which file "wins" is undefined. The fix for this relied on both pages being named foo; but in the above cases, the source files have different pagenames.

One approach: Beef up checking in will_render to detect when the same destination file is rendered by multiple pages. Or when one page renders a file that is a parent directory of the rendered file of another page. It could warn, rather than erroring. The last page rendered would "win"; generating the destdir file.

done