view tests/test-issue522 @ 10189:e451e599fbcf

patch: support diff data loss detection and upgrade

In worst case, generating diff in upgrade mode can be two times more expensive
than generating it in git mode directly: we may have to regenerate the whole
diff again whenever a git feature is detected. Also, the first diff attempt is
completely buffered instead of being streamed. That said, even without having
profiled it yet, I am convinced we can fast-path the upgrade mode if necessary
were it to be used in regular diff commands, and not only in mq where avoiding
data loss is worth the price.

#!/bin/sh

# In the merge below, the file "foo" has the same contents in both
# parents, but if we look at the file-level history, we'll notice that
# the version in p1 is an ancestor of the version in p2.  This test
# makes sure that we'll use the version from p2 in the manifest of the
# merge revision.

hg init repo
cd repo

echo foo > foo
hg ci -qAm 'add foo'

echo bar >> foo
hg ci -m 'change foo'

hg backout -r tip -m 'backout changed foo'

hg up -C 0
touch bar
hg ci -qAm 'add bar'

hg merge --debug
hg debugstate | grep foo
hg st -A foo
hg ci -m 'merge'

hg manifest --debug | grep foo
hg debugindex .hg/store/data/foo.i