histedit: switch state to store node instead of ctx Currently, if the node no longer exists, the state object fails to load and pukes with an exception. Changing the state object to only store the node allows callers to handle these cases. For instance, in bootstrapcontinue we can now detect that the node doesn't exist and exit gracefully. The alternative is to have the state object store something like None when the node doesn't exist, but then outside callers won't be able to access the old node for recovery (unless we store both the node and the ctx, but why bother). More importantly it allows us to detect this case when doing hg histedit --abort. Currently this situation results in both --continue and --abort being broken and the user has to rm .hg/histedit-state to unwedge their repo. (description by Durham Goode)

histedit: don't allow to strip nodes which are necessary to continue histedit During histedit we don't want user to do any operation resulting in stripping nodes needed to continue history editing. This patch wraps the strip function to detect such situations.

subrepo: add tests for change/remove conflicts There are currently no tests for change/remove conflicts of subrepos, and it's pretty broken. Add some tests demonstrating some of the breakages and fix the most obvious one (a KeyError when trying to look up a subrepo in the wrong context).

hgweb: recreate old DOM structure for css in monoblue style There's a "p.changeset-age span" css block in style-monoblue.css with quite a bit of rules, including position. They were all unused, since there weren't matching span element inside the p.changeset-age. The span was removed in b24e5a708fad (as it seemed meaningless at the time?) and since then relative changeset age text looked weird and broken. "age" class is used for calculating relative changeset age in javascript: all content of such element is replaced with human-friendly text (e.g. "yesterday"). So the new span gets the age class.

shellquote: fix missing quotes for empty string "hg kdiff3 -rREV" did not work because 1642eb429536 and 5edb387158a1 failed to handle empty argument.

trydiff: transpose 'if opts.git or losedatafn' with 'if f[12]' Perhaps it's more readable this way...

trydiff: extract function that generates filename pairs The code that identifies copies/renames, as well as the filenames before and after, is now isolated and we can extract it to a function so it can be overridden by extensions (in particular the narrow clone extension).

trydiff: read file data in only one place This moves getfilectx() out of the initial block in the loop, leaving that block to be only about finding pairs of filenames in ctx1 and ctx2 to diff.