tests/test-merge-default

findrenames: Optimise "addremove -s100" by matching files by their SHA1 hashes.

We speed up 'findrenames' for the usecase when a user specifies they
want a similarity of 100% by matching files by their exact SHA1 hash
value. This reduces the number of comparisons required to find exact
matches from O(n^2) to O(n).

While it would be nice if we could just use mercurial's pre-calculated
SHA1 hash for existing files, this hash includes the file's ancestor
information making it unsuitable for our purposes. Instead, we calculate
the hash of old content from scratch.

The following benchmarks were taken on the current head of crew:

addremove 100% similarity:
  rm -rf *; hg up -C; mv tests tests.new
  hg --time addremove -s100 --dry-run

  before:  real 176.350 secs (user 128.890+0.000 sys 47.430+0.000)
  after:   real   2.130 secs (user   1.890+0.000 sys  0.240+0.000)

addremove 75% similarity:
  rm -rf *; hg up -C; mv tests tests.new; \
      for i in tests.new/*; do echo x >> $i; done
  hg --time addremove -s75  --dry-run

  before: real 264.560 secs (user 215.130+0.000 sys 49.410+0.000)
  after:  real 218.710 secs (user 172.790+0.000 sys 45.870+0.000)

#!/bin/sh

hg init
echo a > a
hg commit -A -ma

echo b >> a
hg commit -mb

echo c >> a
hg commit -mc

hg up 1
echo d >> a
hg commit -md

hg up 1
echo e >> a
hg commit -me

hg up 1
echo % should fail because not at a head
hg merge

hg up
echo % should fail because \> 2 heads
HGMERGE=internal:other; export HGMERGE
hg merge

echo % should succeed
hg merge 2
hg commit -mm1

echo % should succeed - 2 heads
hg merge -P
hg merge
hg commit -mm2

echo % should fail because at tip
hg merge

hg up 0
echo % should fail because 1 head
hg merge

hg up 3
echo f >> a
hg branch foobranch
hg commit -mf
echo % should fail because merge with other branch
hg merge

# Test for issue2043: ensure that 'merge -P' shows ancestors of 6 that
# are not ancestors of 7, regardless of where their least common
# ancestor is.
echo % merge preview not affected by common ancestor
hg up -q 7
hg merge -q -P 6         # expect: 2, 4, 5, 6

true