view tests/test-pull-pull-corruption2 @ 8849:80cc4b1a62d0

compare grep result between target and its parent

I found that typical case is that grep target is added at (*) revision
in the tree shown below.

     +--- 1(*) --- 3
     0
     +--- 2 ------ 4

Now, I expect 'hg grep --all' to show only rev:1 which is first
appearance of target line.

But 'hg grep --all' will tell:

  target line dis-appeared at 3 => 4
  target line     appeared at 2 => 3
  target line dis-appeared at 1 => 2
  target line     appeared at 0 => 1

because current 'hg grep' implementation compares not between target
revision and its parent, but between neighbor revisions in walkthrough
order.

I checked performance of this patch by "hg grep --follow --all
walkchangerevs" on whole Mercurial repo, and patched version could
complete as fast as un-patched one.

#!/bin/sh
#
# Corrupt an hg repo with two pulls.
#

# create one repo with a long history
hg init source1
cd source1
touch foo
hg add foo
for i in 1 2 3 4 5 6 7 8 9 10; do
    echo $i >> foo
    hg ci -m $i
done
cd ..

# create a third repo to pull both other repos into it
hg init version2
hg -R version2 pull source1 &
sleep 1

hg clone --pull -U version2 corrupted
wait
hg -R corrupted verify
hg -R version2 verify