view tests/test-identify.out @ 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.

% no repo
abort: There is no Mercurial repository here (.hg not found)
% create repo
adding a
% basic id usage
cb9a9f314b8b tip
cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b tip
cb9a9f314b8b
cb9a9f314b8b tip
% with options
cb9a9f314b8b tip
0
tip
default
cb9a9f314b8b
cb9a9f314b8b 0 default tip
% with modifications
cb9a9f314b8b+ 0+ default tip
% other local repo
cb9a9f314b8b+ tip
cb9a9f314b8b+ tip
% with remote http repo
cb9a9f314b8b
% remote with tags?
abort: can't query remote revision number, branch, or tags