pull: add source information to the transaction
The source information can, should be applied once when opening the transaction
for the pull. This will lets element processed within a bundle2 be aware of them
and open the door to running a set of hooks when closing this pull transaction.
This is similar to what is done in server's unbundle call.
$ hg init t
$ cd t
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ rm b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg add b
$ hg commit -m "commit #2"
created new head
$ cd ..; rm -r t
$ mkdir t
$ cd t
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ rm b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg commit -A -m "commit #2"
adding b
created new head
$ cd ..; rm -r t
$ hg init t
$ cd t
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ rm b
$ hg remove b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg commit -A -m "commit #2"
adding b
created new head
$ cd ..