template: add predecessors template
Add a 'predecessors' template that returns the list of all closest known
predecessors for a changectx. The elements of the list are row changectx node id
formatted by default as short nodes.
The "closest predecessors" are the first locally known revisions encountered
while, walking predecessors markers. For example:
1) If a (A, (B)) markers exists and both A and B are locally known A is a
closest predecessors of B.
2) If a (A, (B)) and (B, (C)) markers exists and only A and C are known
locally, A will be the closest precursors of C.
This logic respect repository filtering. So hidden revision will be skipped by
this logic unless --hidden is specified. Since we only display the visible
predecessors, this template will not display anything in most case. It makes a
good candidate for inclusion in the default log output.
I added a new test-file for testing the precursors in various scenarios. This
test file will also be used for the successors template.
A new "obsutil" module has been added to start gathering utility function
outside of the large obsolete.py module.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> drawdag=$TESTDIR/drawdag.py
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: {desc}"
> EOF
$ rebasewithdag() {
> N=`$PYTHON -c "print($N+1)"`
> hg init repo$N && cd repo$N
> hg debugdrawdag
> hg rebase "$@" > _rebasetmp
> r=$?
> grep -v 'saved backup bundle' _rebasetmp
> [ $r -eq 0 ] && hg tglog
> cd ..
> return $r
> }
Single branching point, without merge:
$ rebasewithdag -b D -d Z <<'EOS'
> D E
> |/
> Z B C # C: branching point, E should be picked
> \|/ # B should not be picked
> A
> |
> R
> EOS
rebasing 3:d6003a550c2c "C" (C)
rebasing 5:4526cf523425 "D" (D)
rebasing 6:b296604d9846 "E" (E tip)
o 6: E
|
| o 5: D
|/
o 4: C
|
o 3: Z
|
| o 2: B
|/
o 1: A
|
o 0: R
Multiple branching points caused by selecting a single merge changeset:
$ rebasewithdag -b E -d Z <<'EOS'
> E
> /|
> B C D # B, C: multiple branching points
> | |/ # D should not be picked
> Z | /
> \|/
> A
> |
> R
> EOS
rebasing 2:c1e6b162678d "B" (B)
rebasing 3:d6003a550c2c "C" (C)
rebasing 6:5251e0cb7302 "E" (E tip)
o 6: E
|\
| o 5: C
| |
o | 4: B
|/
o 3: Z
|
| o 2: D
|/
o 1: A
|
o 0: R
Rebase should not extend the "--base" revset using "descendants":
$ rebasewithdag -b B -d Z <<'EOS'
> E
> /|
> Z B C # descendants(B) = B+E. With E, C will be included incorrectly
> \|/
> A
> |
> R
> EOS
rebasing 2:c1e6b162678d "B" (B)
rebasing 5:5251e0cb7302 "E" (E tip)
o 5: E
|\
| o 4: B
| |
| o 3: Z
| |
o | 2: C
|/
o 1: A
|
o 0: R
Rebase should not simplify the "--base" revset using "roots":
$ rebasewithdag -b B+E -d Z <<'EOS'
> E
> /|
> Z B C # roots(B+E) = B. Without E, C will be missed incorrectly
> \|/
> A
> |
> R
> EOS
rebasing 2:c1e6b162678d "B" (B)
rebasing 3:d6003a550c2c "C" (C)
rebasing 5:5251e0cb7302 "E" (E tip)
o 5: E
|\
| o 4: C
| |
o | 3: B
|/
o 2: Z
|
o 1: A
|
o 0: R
The destination is one of the two branching points of a merge:
$ rebasewithdag -b F -d Z <<'EOS'
> F
> / \
> E D
> / /
> Z C
> \ /
> B
> |
> A
> EOS
nothing to rebase
[1]
Multiple branching points caused by multiple bases (issue5420):
$ rebasewithdag -b E1+E2+C2+B1 -d Z <<'EOS'
> Z E2
> | /
> F E1 C2
> |/ /
> E C1 B2
> |/ /
> C B1
> |/
> B
> |
> A
> |
> R
> EOS
rebasing 3:a113dbaa660a "B1" (B1)
rebasing 5:06ce7b1cc8c2 "B2" (B2)
rebasing 6:0ac98cce32d3 "C1" (C1)
rebasing 8:781512f5e33d "C2" (C2)
rebasing 9:428d8c18f641 "E1" (E1)
rebasing 11:e1bf82f6b6df "E2" (E2)
o 12: E2
|
o 11: E1
|
| o 10: C2
| |
| o 9: C1
|/
| o 8: B2
| |
| o 7: B1
|/
o 6: Z
|
o 5: F
|
o 4: E
|
o 3: C
|
o 2: B
|
o 1: A
|
o 0: R
Multiple branching points with multiple merges:
$ rebasewithdag -b G+P -d Z <<'EOS'
> G H P
> |\ /| |\
> F E D M N
> \|/| /| |\
> Z C B I J K L
> \|/ |/ |/
> A A A
> EOS
rebasing 2:dc0947a82db8 "C" (C)
rebasing 8:215e7b0814e1 "D" (D)
rebasing 9:03ca77807e91 "E" (E)
rebasing 10:afc707c82df0 "F" (F)
rebasing 13:018caa673317 "G" (G)
rebasing 14:4f710fbd68cb "H" (H)
rebasing 3:08ebfeb61bac "I" (I)
rebasing 4:a0a5005cec67 "J" (J)
rebasing 5:83780307a7e8 "K" (K)
rebasing 6:e131637a1cb6 "L" (L)
rebasing 11:d6fe3d11d95d "M" (M)
rebasing 12:fa1e02269063 "N" (N)
rebasing 15:448b1a498430 "P" (P tip)
o 15: P
|\
| o 14: N
| |\
o \ \ 13: M
|\ \ \
| | | o 12: L
| | | |
| | o | 11: K
| | |/
| o / 10: J
| |/
o / 9: I
|/
| o 8: H
| |\
| | | o 7: G
| | |/|
| | | o 6: F
| | | |
| | o | 5: E
| | |/
| o | 4: D
| |\|
+---o 3: C
| |
o | 2: Z
| |
| o 1: B
|/
o 0: A
Slightly more complex merge case (mentioned in https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-November/091074.html):
$ rebasewithdag -b A3+B3 -d Z <<'EOF'
> Z C1 A3 B3
> | / / \ / \
> M3 C0 A1 A2 B1 B2
> | / | | | |
> M2 M1 C1 C1 M3
> |
> M1
> |
> M0
> EOF
rebasing 4:8817fae53c94 "C0" (C0)
rebasing 6:06ca5dfe3b5b "B2" (B2)
rebasing 7:73508237b032 "C1" (C1)
rebasing 9:fdb955e2faed "A2" (A2)
rebasing 11:1b2f368c3cb5 "A3" (A3)
rebasing 10:0a33b0519128 "B1" (B1)
rebasing 12:bd6a37b5b67a "B3" (B3 tip)
o 12: B3
|\
| o 11: B1
| |
| | o 10: A3
| | |\
| +---o 9: A2
| | |
| o | 8: C1
| | |
o | | 7: B2
| | |
| o | 6: C0
|/ /
o | 5: Z
| |
o | 4: M3
| |
o | 3: M2
| |
| o 2: A1
|/
o 1: M1
|
o 0: M0
Disconnected graph:
$ rebasewithdag -b B -d Z <<'EOS'
> B
> |
> Z A
> EOS
nothing to rebase from 112478962961 to 48b9aae0607f
[1]
Multiple roots. Roots are ancestors of dest:
$ rebasewithdag -b B+D -d Z <<'EOF'
> D Z B
> \|\|
> C A
> EOF
rebasing 2:112478962961 "B" (B)
rebasing 3:b70f76719894 "D" (D)
o 4: D
|
| o 3: B
|/
o 2: Z
|\
| o 1: C
|
o 0: A
Multiple roots. One root is not an ancestor of dest:
$ rebasewithdag -b B+D -d Z <<'EOF'
> Z B D
> \|\|
> A C
> EOF
nothing to rebase from 86d01f49c0d9+b70f76719894 to 262e37e34f63
[1]
Multiple roots. One root is not an ancestor of dest. Select using a merge:
$ rebasewithdag -b E -d Z <<'EOF'
> E
> |\
> Z B D
> \|\|
> A C
> EOF
rebasing 2:86d01f49c0d9 "B" (B)
rebasing 5:539a0ff83ea9 "E" (E tip)
o 5: E
|\
| o 4: B
| |\
| | o 3: Z
| | |
o | | 2: D
|/ /
o / 1: C
/
o 0: A
Multiple roots. Two children share two parents while dest has only one parent:
$ rebasewithdag -b B+D -d Z <<'EOF'
> Z B D
> \|\|\
> A C A
> EOF
rebasing 2:86d01f49c0d9 "B" (B)
rebasing 3:b7df2ca01aa8 "D" (D)
o 4: D
|\
+---o 3: B
| |/
| o 2: Z
| |
o | 1: C
/
o 0: A