extdiff: add some comments in diffrevs()
It was not obvious to understand the code so I added some comments.
Differential Revision: https://phab.mercurial-scm.org/D8690
--- a/hgext/extdiff.py Tue Jul 07 13:26:57 2020 +0530
+++ b/hgext/extdiff.py Tue Jul 07 14:01:12 2020 +0530
@@ -398,6 +398,8 @@
):
subrepos = opts.get(b'subrepos')
+
+ # calculate list of files changed between both revs
st = repo.status(node1a, node2, matcher, listsubrepos=subrepos)
mod_a, add_a, rem_a = set(st.modified), set(st.added), set(st.removed)
if do3way:
@@ -413,11 +415,18 @@
common = modadd | rem_a | rem_b
if not common:
return 0
+
# Always make a copy of node1a (and node1b, if applicable)
+ # dir1a should contain files which are:
+ # * modified or removed from node1a to node2
+ # * modified or added from node1b to node2
+ # (except file added from node1a to node2 as they were not present in
+ # node1a)
dir1a_files = mod_a | rem_a | ((mod_b | add_b) - add_a)
dir1a = snapshot(ui, repo, dir1a_files, node1a, tmproot, subrepos)[0]
rev1a = b'@%d' % repo[node1a].rev()
if do3way:
+ # file calculation criteria same as dir1a
dir1b_files = mod_b | rem_b | ((mod_a | add_a) - add_b)
dir1b = snapshot(ui, repo, dir1b_files, node1b, tmproot, subrepos)[0]
rev1b = b'@%d' % repo[node1b].rev()