checkunknown: audit path before checking if it's a file or link Previously we would lstat the file to see if it was a file or a link before attempting to process it. If the file happened to exist across a symlink, and if that symlink was pointing to a network file system, that check could be very expensive. The new logic audit's the path to avoid symlinks before performing the lstat on the file itself. In our situation, this shaved 10 minutes off of certain hg updates. 300 files * (2 seconds - the network filesystem lookup time)

pathauditor: change parts verification order to be root first Previously, when we verified the parts of a path in the auditor, we would validate the deepest directory first, then it's parent, and so on up to the root. If there happened to be a symlink in the chain, that meant our first check would likely traverse that symlink. In some cases that symlink might point to a network filesystem that is expensive, and therefore this simple check could be very slow. The fix is to check the path parts starting at the root and working our way down. This has a minor performance difference in that we used to be able to short circuit from the audit if we reached a directory that had already been checked. Now we can't, but the cost is N dictionary look ups, where N is the number of parts in the path, which should be fairly minor.

chg: forward job control signals to worker process (issue5051) This is necessary to suspend/resume long pulls, interactive curses session, etc. The implementation is based on emacsclient, but our version doesn't test if chg process is foreground or not before propagating SIGCONT. This is because chg isn't always an interactive session. If we copy the SIGTTIN/SIGTTOU emulation from emacsclient, non-interactive session can't be moved to a background job. $ chg pull ^Z suspended $ bg %1 [1] continued [1] suspended (tty input) # wrong https://github.com/emacs-mirror/emacs/blob/0e96320/lib-src/emacsclient.c#L1094

chg: verify return value of sigaction() and sigemptyset() They should never fail, but it couldn't hurt to be a paranoid.

chg: initialize sigaction fields more reliably It seems calling memset() and sigemptyset() is common pattern to initialize sigaction. And strictly speaking, sigset_t must be initialized by sigemptyset() or sigfillset(). I saw git and uwsgi do that way, so let's follow them.

tests: confirm that a badly documented extension doesn't cause a crash An external extension whose docstring doesn't conform to Mercurial standards used to cause crashes. Test that we omit such extensions when you do a keyword search.

bookmarks: avoid creating a nested repository during testing This helps the test to pass with hgwatchman, which would otherwise need to be taught about a nested .hg directory. hgwatchman already blacklists test-nested-repo.t which covers the actual usecase

dispatch: strip command line options like config file options Currently, whitespace in command line --config options are considered significant while whitespace in config files are not considered significant. This diff strips the leading and trailing whitespace from command line config options.

hook: for python hook ImportErrors, add note to run with --traceback I personally found it completely non-obvious that --traceback prints out stack traces for failed imports.

hook: fewer parentheses for hook load errors This matches 'hook failed' warnings. We're also going to add hints to some of the hook load errors. Without this change we'd have two pairs of parens for a single error message, which looks really cluttered.