revsetbenchmark: handle exception case If the revset being benchmarked has an exception, the handling code was encountering an error because the exception did not always have an "output" attribute (I think it's a python 2.7 thing).

merge: minimize conflicts when common base is not shown (issue4447) Previously, two changes that were nearly, but not quite, identical would result in large merge conflict regions that looked very similar, and were thus very confusing to users, and lead people used to other source control systems to claim that "mercurial's merge algorithms suck". In the relatively common case of a new file being introduced in two branches with very slight modifications, the old behavior would show the entire file as a conflict, and it would be very difficult for a user to determine what was going on. In the past, mercurial attempted to solve this with a "very smart" algorithm that would find all common lines, but this has significant problems as described in 2ea6d906cf9b. Instead, we use a "very dumb" algorithm introduced in the previous patch that simply matches lines at the periphery of conflict regions. This minimizes most conflict regions well, though there may still be some degenerate edge cases, like small modification to the beginning and end of a large file.

merge: introduce method to minimize merge regions In the next diff, we will use this to trim down the start and end of conflict regions where the A and B sides both made the same changes.

merge: add some useful documentation

encoding: backport paranoid escaping from templatefilters.jsonescape() This was introduced by 55c763926a28. It is required to embed JSON data in HTML page. Convince yourself here: http://escape.alf.nu/1

encoding: add option to escape non-ascii characters in JSON This is necessary for hgweb to embed JSON data in HTML. JSON data must be able to be embedded in non-UTF-8 HTML page so long as the page encoding is compatible with ASCII. According to RFC 7159, non-BMP character is represented as UTF-16 surrogate pair. This function first splits an input string into an array of UTF-16 code points. https://tools.ietf.org/html/rfc7159.html#section-7

encoding: initialize jsonmap when module is loaded This makes jsonescape() a thread-safe function, which is necessary for hgweb. The initialization stuff isn't that slow: $ python -m timeit -n1000 -s 'from mercurial import encoding as x' 'reload(x)' original: 1000 loops, best of 3: 158 usec per loop this patch: 1000 loops, best of 3: 214 usec per loop compared to loading the commands module: $ python -m timeit -n1000 -s 'from mercurial import commands as x' 'reload(x)' 1000 loops, best of 3: 1.11 msec per loop

encoding: change jsonmap to a list indexed by code point This is slightly faster and convenient to implement a paranoid escaping. $ python -m timeit \ -s 'from mercurial import encoding; data = str(bytearray(xrange(128)))' \ 'encoding.jsonescape(data)' original: 100000 loops, best of 3: 15.1 usec per loop this patch: 100000 loops, best of 3: 13.7 usec per loop

update: change default destination to tipmost descendant (issue4673) (BC) Bare 'hg update' now brings you to the tipmost descendant (on the same branch). Leaving the user on the same topological branch. The previous behavior, updating to the tipmost changeset on the same branch could lead to jump from a topological branch to another. This was confusing and impractical. As the only conceivable reason for the old behavior have been address by the recently introduce message about other heads, we can "safely" change this behavior All test changes have been reviewed and seen a valid consequences.

test: drop useless --update flag in issue1502 tests The --update is unrelated to the test and has no effect as it fails anyway. Dropping it reduces the noise in the coming change in default destination for update.