commit: if interactive, look elsewhere for whitespace settings (BC) Previously, when doing `commit -i`, we respected `diff.ignorews` and other whitespace-related settings, which is probably unexpected. The primary reason for this is to support hgext.record's commandline options, it's probably accidental that the `[diff]` settings were also considered. See comments on issue6042 and D5490. This can cause problems (issue5839, issue6042). It is assumed by the author that the `[diff]` section is primarily for *viewing* diffs, and that it is unlikely what people intend when attempting to commit or revert. With this change, if a user wants the behavior, they can clone their `[diff]` settings to `commands.commit.interactive.<setting>`. This is thus a mild BC change, but one I suspect is not going to be relied on by anyone. Note: while doing a partial commit/revert, we do not know what command the user is actually running. This means that the split extension, which ends up calling into this code, will respect the `commands.commit.interactive.<setting>` settings, and not a hypothetical `commands.split.interactive.<setting>`. This *also* means that setting `commands.commit.interactive.ignoreblanklines`, for example, will still cause issue5839. Considering the highly unlikely chance that a user actually sets `commands.commit.interactive.<setting>`, the author deems this risk acceptable. Differential Revision: https://phab.mercurial-scm.org/D5834