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
Test EOL update
$ cat >> $HGRCPATH <<EOF
> [diff]
> git = 1
> EOF
$ seteol () {
> if [ $1 = "LF" ]; then
> EOL='\n'
> else
> EOL='\r\n'
> fi
> }
$ makerepo () {
> echo
> echo "# ==== setup repository ===="
> echo '% hg init'
> hg init repo
> cd repo
>
> cat > .hgeol <<EOF
> [patterns]
> **.txt = LF
> EOF
>
> printf "first\nsecond\nthird\n" > a.txt
> printf "f\r\n" > f
> hg commit --addremove -m 'LF commit'
>
> cat > .hgeol <<EOF
> [patterns]
> **.txt = CRLF
> f = LF
> EOF
>
> printf "first\r\nsecond\r\nthird\r\n" > a.txt
> printf "f\n" > f
> hg commit -m 'CRLF commit'
>
> cd ..
> }
$ dotest () {
> seteol $1
>
> echo
> echo "% hg clone repo repo-$1"
> hg clone --noupdate repo repo-$1
> cd repo-$1
>
> cat > .hg/hgrc <<EOF
> [extensions]
> eol =
> EOF
>
> hg update
>
> echo '% a.txt (before)'
> cat a.txt
>
> printf "first${EOL}third${EOL}" > a.txt
>
> echo '% a.txt (after)'
> cat a.txt
> echo '% hg diff'
> hg diff
>
> echo '% hg update 0'
> hg update 0
>
> echo '% a.txt'
> cat a.txt
> echo '% hg diff'
> hg diff
>
>
> cd ..
> rm -r repo-$1
> }
$ makerepo
# ==== setup repository ====
% hg init
adding .hgeol
adding a.txt
adding f
$ dotest LF
% hg clone repo repo-LF
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
% a.txt (before)
first\r (esc)
second\r (esc)
third\r (esc)
% a.txt (after)
first
third
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg update 0
merging a.txt
2 files updated, 1 files merged, 0 files removed, 0 files unresolved
% a.txt
first
third
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first
-second
third
$ dotest CRLF
% hg clone repo repo-CRLF
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
% a.txt (before)
first\r (esc)
second\r (esc)
third\r (esc)
% a.txt (after)
first\r (esc)
third\r (esc)
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first\r (esc)
-second\r (esc)
third\r (esc)
% hg update 0
merging a.txt
2 files updated, 1 files merged, 0 files removed, 0 files unresolved
% a.txt
first
third
% hg diff
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,2 @@
first
-second
third
Test in repo using eol extension, while keeping an eye on how filters are
applied:
$ cd repo
$ hg up -q -c -r null
$ cat > .hg/hgrc <<EOF
> [extensions]
> eol =
> EOF
Update to revision 0 which has no .hgeol, shouldn't use any filters, and
obviously should leave things as tidy as they were before the clean update.
$ hg up -c -r 0 -v --debug
resolving manifests
branchmerge: False, force: False, partial: False
ancestor: 000000000000, local: 000000000000+, remote: 15cbdf8ca3db
calling hook preupdate.eol: hgext.eol.preupdate
.hgeol: remote created -> g
getting .hgeol
filtering .hgeol through isbinary
a.txt: remote created -> g
getting a.txt
filtering a.txt through tolf
f: remote created -> g
getting f
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg st
$ hg branch b
marked working directory as branch b
(branches are permanent and global, did you want a bookmark?)
$ hg ci -m b
Merge changes that apply a filter to f:
$ hg merge 1
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st
M .hgeol
M a.txt
M f
$ hg diff
diff --git a/.hgeol b/.hgeol
--- a/.hgeol
+++ b/.hgeol
@@ -1,2 +1,3 @@
[patterns]
-**.txt = LF
+**.txt = CRLF
+f = LF
diff --git a/a.txt b/a.txt
--- a/a.txt
+++ b/a.txt
@@ -1,3 +1,3 @@
-first
-second
-third
+first\r (esc)
+second\r (esc)
+third\r (esc)
diff --git a/f b/f
--- a/f
+++ b/f
@@ -1,1 +1,1 @@
-f\r (esc)
+f
Abort the merge with up -C to revision 0.
Note that files are filtered correctly for revision 0: f is not filtered, a.txt
is filtered with tolf, and everything is left tidy.
$ touch .hgeol * # ensure consistent dirtyness checks ignoring dirstate
$ hg up -C -r 0 -v --debug
eol: detected change in .hgeol
resolving manifests
branchmerge: False, force: True, partial: False
ancestor: 1db78bdd3bd6+, local: 1db78bdd3bd6+, remote: 15cbdf8ca3db
calling hook preupdate.eol: hgext.eol.preupdate
.hgeol: remote is newer -> g
getting .hgeol
filtering .hgeol through isbinary
a.txt: remote is newer -> g
getting a.txt
filtering a.txt through tolf
f: remote is newer -> g
getting f
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch .hgeol *
$ hg st --debug
eol: detected change in .hgeol
filtering .hgeol through isbinary
filtering a.txt through tolf
skip updating dirstate: identity mismatch (?)
$ hg diff
Things were clean, and updating again will not change anything:
$ touch .hgeol *
$ hg up -C -r 0 -v --debug
eol: detected change in .hgeol
filtering .hgeol through isbinary
filtering a.txt through tolf
resolving manifests
branchmerge: False, force: True, partial: False
ancestor: 15cbdf8ca3db+, local: 15cbdf8ca3db+, remote: 15cbdf8ca3db
calling hook preupdate.eol: hgext.eol.preupdate
starting 4 threads for background file closing (?)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch .hgeol *
$ hg st --debug
eol: detected change in .hgeol
filtering .hgeol through isbinary
filtering a.txt through tolf
$ cd ..
$ rm -r repo