unionrepo: read-only operations on a union of two localrepos
unionrepo is just like bundlerepo without bundles.
The implementation is very similar to bundlerepo, but I don't see any obvious
way to generalize it.
Some most obvious use cases for this would be log and diff across local repos,
as a kind of preview of pulls, for instance:
$ hg -R union:repo1+repo2 heads
$ hg -R union:repo1+repo2 log -r REPO1REV -r REPO2REV
$ hg -R union:repo1+repo2 log -r '::REPO1REV-::REPO2REV'
$ hg -R union:repo1+repo2 log -r 'ancestor(REPO1REV,REPO2REV)'
$ hg -R union:repo1+repo2 diff -r REPO1REV -r REPO2REV
This is going to be used in RhodeCode, and Bitbucket already uses something
similar. Having a core implementation would be beneficial.
$ hg init
$ mkdir alpha
$ touch alpha/one
$ mkdir beta
$ touch beta/two
$ hg add alpha/one beta/two
$ hg ci -m "start"
$ echo 1 > alpha/one
$ echo 2 > beta/two
everything
$ hg diff --nodates
diff -r 7d5ef1aea329 alpha/one
--- a/alpha/one
+++ b/alpha/one
@@ -0,0 +1,1 @@
+1
diff -r 7d5ef1aea329 beta/two
--- a/beta/two
+++ b/beta/two
@@ -0,0 +1,1 @@
+2
beta only
$ hg diff --nodates beta
diff -r 7d5ef1aea329 beta/two
--- a/beta/two
+++ b/beta/two
@@ -0,0 +1,1 @@
+2
inside beta
$ cd beta
$ hg diff --nodates .
diff -r 7d5ef1aea329 beta/two
--- a/beta/two
+++ b/beta/two
@@ -0,0 +1,1 @@
+2
$ cd ..