debugdeltachain: protect against 0 readsize If you don't read any data, read density should be 1.

debugdeltachain: avoid division by zero when a chain is empty The two ratios chainratio and extraratio are computed using dividers that may be zero when the file is empty. As the denominators are integers, the limit of the ratio "just before zero" is the numerator value itself. If the numerator itself is zero, the ratio value is still meaningful: in both cases, a "good" value is a low ratio, and a size of zero is the optimal case.

tests: prevent conflict markers in test case from triggering warnings Broadly, having lines that begin with several '<' tends to trigger tools that try to warn you about unresolved conflicts. It will save some headaches to tweak this string literal to avoid that. Differential Revision: https://phab.mercurial-scm.org/D3897

revlog: enforce chunk slicing down to a certain size Limit maximum chunk size to 4x final size when reading a revision from a revlog. We only apply this logic when the target size is known from the revlog. Ideally, revlog's delta chain would be written in a way that does not trigger this extra slicing often. However, having this second guarantee that we won't read unexpectedly large amounts of memory in all cases is important for the future. Future delta chain building algorithms might have good reason to create delta chain with such characteristics. Including this code in core as soon as possible will make Mercurial 4.7 forward-compatible with such improvement.

revlog: postprocess chunk to slice them down to a certain size After the density slicing is done, we enforce a maximum chunk size to avoid memory consumption issue.

revlog: add function to slice chunk down to a given size It is possible to encounter situations where the slicing based on density did not achieve chunk smaller than the 4*textlength limit. To avoid extra memory consumption in those cases, we need to be able to break down chunk to a given size. Actual caller comes in the next changesets.

revlog: extract density based slicing into its own function We are going to introduce another slicing step. We start by extracting the existing one into its own function.

revlog: document and test _slicechunk

revlog: add a doctest for _segmentspan

revlog: add a doctest to _trimchunk

revlog: introduce a tiny mock of a revlog class This will be used in various function doctest added in the next changesets. The class seems small enough to live in the module directly.

revlog: _segmentspan computes the byte span of a segment Refactor out this code to be used somewhere else in a next changeset

revlog: early return in _slicechunk when span is already small enough If the full span is smaller than the minimum gap size we'll consider, we know we won't do any slicing and we can return earlier.

revlog: early return in _slicechunk when density is already good We don't need to do anything if we know we won't enter the second while loop. Save the overhead of the first loop by returning earlier.

sparse-read: discard gap below 65K only Testing on actual data shows that 65K is more efficient in both time and memory than 256K.

sparse-read: target density of 50% instead of 25% The target density value is wrong. The default target chain span is 4*text-length. However, the target max chain payload is 2*text-length. So default target density should be 50% (2/4) not 25% (1/4).

grep: change default behaviour to search working directory files (BC) With this patch, grep searches on the working directory by default and looks for all files tracked by the working directory and greps on them. ### OLD BEHAVIOUR $ hg init a $ cd a $ echo "some text">>file1 $ hg add file1 $ hg commit -m "adds file1" $ hg mv file1 file2 $ hg grep "some" `file2:1:some text` `file1:0:some text` This behaviour is undesirable since file1 is not in the current history and was renamed as file2, so the second result was redundant and confusing. ### NEW BEHAVIOUR $ hg init a $ cd a $ echo "some text">>file1 $ hg add file1 $ hg commit -m "adds file1" $ hg mv file1 file2 $ hg grep "some" `file2:2147483647:some text` Differential Revision: https://phab.mercurial-scm.org/D3826

patch: don't separate \r and \n when colorizing diff output When displaying diffs, \r at the end of a line is treated as trailing whitespace. This causes an ANSI escape code to be inserted between \r and \n. Some programs, such as less since version 530 (maybe earlier, but at least not version 487) displays ^M when it encounters a lone \r. This causes a lot of noise in diff output on Windows, where \r\n is used to terminate lines. We avoid that by treating both \n and \r\n as end of line when considering trailing whitespace.

hook: add support for disabling the shell to native command translation I think having it on by default is the right thing to do, but this is an escape hatch if someone has a command that shouldn't be mangled. The inspiration is the priority prefix. The translation does nothing on non Windows platforms, so the default value is selected to avoid printing a useless note by default.

hook: narrow the 'priority' prefix check to align with the documentation A prefix like 'priorityfoo' is meaningless, but `hg help config.hooks` calls out the dot.

windows: don't consider '$$' to be an escaped '$' when translating to cmd.exe This functionality was inherited from `os.path.expandvars()`. But the point of adding this translating code is to be able to write a portable hook, and bash wouldn't replace '$$' with '$'. Escaping with '\' works, and is portable.

contrib: add heads(commonancestors(_)) to all-revsets This is mainly to check that we don't regress our optimization path.

revset: add optimization for heads(commonancestors()) Previously, the only way to get these commits were (tested on mozilla-central): hg perfrevset 'heads(::a7cf55 and ::d8b15)' ! wall 4.988366 comb 4.960000 user 4.780000 sys 0.180000 (best of 3) After this patch: (python) hg perfrevset 'heads(commonancestors(a7cf55 + d8b15))' ! wall 0.002155 comb 0.000000 user 0.000000 sys 0.000000 (best of 1107) (C) hg perfrevset 'heads(commonancestors(a7cf55 + d8b15))' ! wall 0.000568 comb 0.000000 user 0.000000 sys 0.000000 (best of 4646)

revsets: add commonancestors revset This is a method to reproduce "::x and ::y" such that a set can be sent in. For instance, it'd be convenient to have "::heads()" work like this but that already means "::x + ::y + ..." for each element in the "heads()" set. Therefore, we add the "commonancestors" method to mean "::x and ::y ..." for each head in the given set.

tweakdefaults: enable word-diff by default It's another creature comfort in diff output, we may as well include it alongside git-diffs and showfunc.

run-tests: fix a too long line Differential Revision: https://phab.mercurial-scm.org/D3900

run-tests: add missing life-cycle methods on the example custom test result A previous commit introduced `onStart` and `onEnd` methods on test result but the one used in tests lacked those two methods. Fix it and add some output to be sure they are called. Differential Revision: https://phab.mercurial-scm.org/D3899

run-tests: fix test result verbosity A previous refactoring created the test result with a verbosity of 0 hiding some of the outputs in the normal case. Differential Revision: https://phab.mercurial-scm.org/D3898