dirstate-tree: Add tree traversal/iteration
Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.
Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.
This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.
Differential Revision: https://phab.mercurial-scm.org/D10370
Setup extension:
$ cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> [mq]
> git = keep
> EOF
Test merge with mq changeset as the second parent:
$ hg init m
$ cd m
$ touch a b c
$ hg add a
$ hg commit -m a
$ hg add b
$ hg qnew -d "0 0" b
$ hg update 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg add c
$ hg commit -m c
created new head
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m merge
abort: cannot commit over an applied mq patch
[255]
$ cd ..
Issue529: mq aborts when merging patch deleting files
$ checkundo()
> {
> if [ -f .hg/store/undo ]; then
> echo ".hg/store/undo still exists"
> fi
> }
Commit two dummy files in "init" changeset:
$ hg init t
$ cd t
$ echo a > a
$ echo b > b
$ hg ci -Am init
adding a
adding b
$ hg tag -l init
Create a patch removing a:
$ hg qnew rm_a
$ hg rm a
$ hg qrefresh -m "rm a"
Save the patch queue so we can merge it later:
$ hg qsave -c -e
copy $TESTTMP/t/.hg/patches to $TESTTMP/t/.hg/patches.1
$ checkundo
Update b and commit in an "update" changeset:
$ hg up -C init
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo b >> b
$ hg st
M b
$ hg ci -m update
created new head
# Here, qpush used to abort with :
# The system cannot find the file specified => a
$ hg manifest
a
b
$ hg qpush -a -m
merging with queue at: $TESTTMP/t/.hg/patches.1
applying rm_a
now at: rm_a
$ checkundo
$ hg manifest
b
Ensure status is correct after merge:
$ hg qpop -a
popping rm_a
popping .hg.patches.merge.marker
patch queue now empty
$ cd ..
Classic MQ merge sequence *with an explicit named queue*:
$ hg init t2
$ cd t2
$ echo '[diff]' > .hg/hgrc
$ echo 'nodates = 1' >> .hg/hgrc
$ echo a > a
$ hg ci -Am init
adding a
$ echo b > a
$ hg ci -m changea
$ hg up -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg cp a aa
$ echo c >> a
$ hg qnew --git -f -e patcha
$ echo d >> a
$ hg qnew -d '0 0' -f -e patcha2
Create the reference queue:
$ hg qsave -c -e -n refqueue
copy $TESTTMP/t2/.hg/patches to $TESTTMP/t2/.hg/refqueue
$ hg up -C 1
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
Merge:
$ HGMERGE=internal:other hg qpush -a -m -n refqueue
merging with queue at: $TESTTMP/t2/.hg/refqueue
applying patcha
patching file a
Hunk #1 succeeded at 2 with fuzz 1 (offset 0 lines).
fuzz found when applying patch, stopping
patch didn't work out, merging patcha
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
0 files updated, 2 files merged, 0 files removed, 0 files unresolved
applying patcha2
now at: patcha2
Check patcha is still a git patch:
$ cat .hg/patches/patcha
# HG changeset patch
# Parent d3873e73d99ef67873dac33fbcc66268d5d2b6f4
diff --git a/a b/a
--- a/a
+++ b/a
@@ -1,1 +1,2 @@
-b
+a
+c
diff --git a/a b/aa
copy from a
copy to aa
--- a/a
+++ b/aa
@@ -1,1 +1,1 @@
-b
+a
Check patcha2 is still a regular patch:
$ cat .hg/patches/patcha2
# HG changeset patch
# Date 0 0
# Parent ???????????????????????????????????????? (glob)
diff -r ???????????? -r ???????????? a (glob)
--- a/a
+++ b/a
@@ -1,2 +1,3 @@
a
c
+d
$ cd ..