revset: reduce dict lookup in lazyset.__contains__ Avoid an extra dict lookup when we have to compute the value. No visible performance impact but this shaves the yak a few extra nanometers.

revset: do less lookup during spanset.__contains__ Attribute lookup is slow in python. So this version is going to be a bit faster. This does not have a visible impact since the rest of the stack is much slower but this shaves the yak a few extra nanometers. Moreover the new version is more readable so it worth doing this change for code quality purpose. This optimisation was approved by a core python dev.

largefiles: simplify iteration over standins Instead of iterating over all files in the context and ignoring those that are not standins, pass a standin-matcher to the context and iterate over only the files matching. Apart from making the intent clearer, this implementation will also benefit from any future optimizations done to the manifest walking code.

largefiles: avoid using 'lfiles' variable for two purposes The variable 'lfiles' is first used for a set of the names of all the large files. It is then overwritten with a tuple like the ones returned from status(). To reduce confusion, let's create a separate variable for the second use.

largefiles: remove unnecessary clearing of status fields At the end of lfilesrepo.status(), we clear the lists of unknown, ignored and clean files, depending on the values of 'listunknown' etc. The lists originate from other calls to status(), and it is only 'clean' that may get updated after the calls. Let's remove the need to clear any of the lists by explicitly only adding to 'clean' when 'listclean' is true.

mq: simplify patchheader handling of the empty line before the diff Don't try to append empty lines to HG patch headers - instead, add them in str method. This minor change removes some apparently redundant code and makes the code more robust.