revlog: add __contains__ for fast membership test Because revlog implements __iter__, "rev in revlog" works but does silly O(n) lookup unexpectedly. So it seems good to add fast version of __contains__. This allows "rev in repo.changelog" in the next patch.

largefiles: set the extension as enabled locally after a clone requiring it When cloning a repo that requires largefiles, the user had to either enable the extension on the command line and then manually edit the local hgrc file after the clone, or just enable it globally for the user. Since it is a feature of last resort, and materially affects even repos without any largefiles when it is enabled, we should make it easier to not have it enabled globally. This simply adds the enabling statement to the local hgrc if the requires file mandates its use (which only happens after the first largefile is committed). That means that a user who works with a mix of largefile and normal repos can always clone with '--config extensions.largefiles=', and the extension is permanently enabled or not as appropriate. The change in test-largefiles.t is simply because the order of loading rebase and largefiles changed. The same change occurs if the order is flipped in the hgrc file at the top of the test.

color: be more conservative about setting ANSI mode on Windows (BC) The current color mode detection on Windows assumes the presence of the TERM environment variable assumes ANSI is supported. However, this isn't always true. In MSYS (commonly found as part of MinGW), TERM is set to "cygwin" and the auto resolved color mode of "ansi" results in escape sequences getting printed literally to the terminal. The output is very difficult to read and results in a bad user experience. A workaround is to activate the pager and have it attend all commands (GNU less in MSYS can render ANSI terminal sequences properly). In Cygwin, TERM is set to "xterm." Furthermore, Cygwin supports displaying these terminal sequences properly (unlike MSYS). This patch changes the mode auto-detection logic on Windows to be more conservative about selecting the "ansi" mode. We now only select the "ansi" mode if TERM is set and it contains the string "xterm" or if we were unable to talk to win32 APIs to determine the settings. There is a chance this may take away "ansi" from a terminal that actually supports it. The recourse for this would be to patch the detection to act appropriately and to override color.mode until that patch has landed. However, the author believes this regression is tolerable, since it means MSYS users won't have gibberish printed by default. Since MSYS's common pager (less) supports display of ANSI sequences, there is room to patch the color extensions so it can select the ANSI color mode if a pager is activated. Mozilla (being an active user of MSYS) would really appreciate this being part of the stable branch. However, since I believe it is BC, I haven't explicitly requested application to stable since I figure that request will be denied.

merge with stable

bundle2.unpackermixin: control for underlying file descriptor This patch adds seek(), tell(), and close() implementations for unpackermixin which forward to the file descriptor's implementation if possible. A future patch will use this to make bundle2.unbundlepart seekable, which will in turn make it usable as a file descriptor for bundlerepo.

trydiff: join elements in 'header' list by '\n' It seems natural that each element in the list corresponds to one line of output. That is currently true, but only because each element in the list has a trailing newline. Let's drop those newlines and instead add them when we print the headers.

trydiff: move check for quietness out of diffline() By moving the condition out of diffline(), the call site becomes clearer and diffline() no longer closes on any variables. Note that this changes the value of the header variable from [''] to [], but there is no difference in how these two are treated by the following code. The new value seems more natural anyway.

trydiff: remove dead branch in diffline() Since diffline() is never called when 'revs' is empty, it doesn't need to handle that case.