view tests/test-issue1175 @ 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
rm -rf a
hg init a
cd a
touch a
hg ci -Am0
hg mv a a1
hg ci -m1
hg co 0
hg mv a a2
hg up
hg ci -m2

touch a
hg ci -Am3
hg mv a b
hg ci -Am4 a
hg ci --debug --traceback -Am5 b
hg verify
hg export --git tip