simplemerge: stop merging file flags
As
384df4db6520 (merge: merge file flags together with file content,
2013-01-09) explains, we shouldn't do a 3-way merge of the
symlink. However, since
84614212ae39 (flags: actually merge flags in
simplemerge, 2020-05-16), we do that in
`simplemerge.simplemerge()`. What's more, the merging of the
executable flag there isn't actually necessary; it was made a no-op by
the very next commit, i.e.
4234c9af515d (flags: read flag from
dirstate/disk for workingcopyctx (
issue5743), 2020-05-16).
I found the overall flag-merging code (not the bit in
`simplemerge.py`) very hard to follow, but I think I now finally
understand how it works. `mergestate.resolve()` calculates the merged
file flags and sets them on the local side of the merge (confusingly
by calling `_restore_backup()`). Then it calls
`filemerge.filemerge()`, which in turn calls
`simplemerge.simplemerge()` (if premerge is enabled). That means that
the flags on the local side `fcs.flags()` are already correct when the
flag-merging code in `simplemerge.simplemerge()` runs. Interestingly,
that code still works when the local side already has the merged
value, it just doesn't change the value. Here's a truth table to
explain why:
```
BLOMCAR
0000000
0011111
0101011
0111111
1000000
1010000
1100000
1111101
```
B: Base
L: Local
O: Other
M: Merged flags from `mergestate.resolve()`, i.e. what's called "local"
when we get to `simplemerge.simplemerge()`
C: `commonflags` in `simplemerge.simplemerge()`, i.e. `M & O`
A: `addedflags` in `simplemerge.simplemerge()`, i.e. `(M ^ O) - B`
R: Re-merged flags `simplemerge.simplemerge()`, i.e. `C | A`
As you can see, the re-merged flags are always unchanged compared to
the initial merged flags (R equals M).
Therefore, this patch effectively backs out
84614212ae39. (I might
later refactor this code to have the flags explicitly passed in.)
`simplemerge.simplemerge()` is also called from
`contrib/simplemerge.py`, but that code never passes any flags.
Differential Revision: https://phab.mercurial-scm.org/D11879
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> mq=
>
> [mq]
> plain=true
>
> [alias]
> tglog = log -G --template "{rev}: {node|short} '{desc}' tags: {tags}\n"
> EOF
$ hg init a
$ cd a
$ hg qinit -c
$ echo c1 > f
$ hg add f
$ hg ci -m C1
$ echo r1 > f
$ hg ci -m R1
$ hg up -q 0
$ hg qnew f.patch -d '1 0'
$ echo mq1 > f
$ hg qref -m P0
$ hg qnew f2.patch
$ echo mq2 > f
$ hg qref -m P1 -d '2 0'
$ hg tglog
@ 3: 929394423cd3 'P1' tags: f2.patch qtip tip
|
o 2: 3504f44bffc0 'P0' tags: f.patch qbase
|
| o 1: bac9ed9960d8 'R1' tags:
|/
o 0: 36f36ddbca61 'C1' tags: qparent
Rebase - try to rebase on an applied mq patch:
$ hg rebase -s 1 -d 3
abort: cannot rebase onto an applied mq patch
[20]
Rebase - same thing, but mq patch is default dest:
$ hg up -q 1
$ hg rebase
abort: cannot rebase onto an applied mq patch
[20]
$ hg up -q qtip
Rebase - generate a conflict:
$ hg rebase -s 2 -d 1
rebasing 2:3504f44bffc0 f.patch qbase "P0"
merging f
warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
Fix the 1st conflict:
$ echo mq1r1 > f
$ hg resolve -m f
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase -c
rebasing 2:3504f44bffc0 f.patch qbase "P0"
rebasing 3:929394423cd3 f2.patch qtip tip "P1"
merging f
warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
Fix the 2nd conflict:
$ echo mq1r1mq2 > f
$ hg resolve -m f
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase -c
already rebased 2:3504f44bffc0 f.patch qbase "P0" as ebe9914c0d1c
rebasing 3:929394423cd3 f2.patch qtip "P1"
saved backup bundle to $TESTTMP/a/.hg/strip-backup/3504f44bffc0-30595b40-rebase.hg
$ hg tglog
@ 3: 462012cf340c 'P1' tags: f2.patch qtip tip
|
o 2: ebe9914c0d1c 'P0' tags: f.patch qbase
|
o 1: bac9ed9960d8 'R1' tags: qparent
|
o 0: 36f36ddbca61 'C1' tags:
$ hg up -q qbase
$ cat f
mq1r1
$ cat .hg/patches/f.patch
# HG changeset patch
# User test
# Date 1 0
# Thu Jan 01 00:00:01 1970 +0000
# Node ID ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
# Parent bac9ed9960d8992bcad75864a879fa76cadaf1b0
P0
diff -r bac9ed9960d8 -r ebe9914c0d1c f
--- a/f Thu Jan 01 00:00:00 1970 +0000
+++ b/f Thu Jan 01 00:00:01 1970 +0000
@@ -1,1 +1,1 @@
-r1
+mq1r1
Update to qtip:
$ hg up -q qtip
$ cat f
mq1r1mq2
$ cat .hg/patches/f2.patch
# HG changeset patch
# User test
# Date 2 0
# Thu Jan 01 00:00:02 1970 +0000
# Node ID 462012cf340c97d44d62377c985a423f6bb82f07
# Parent ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
P1
diff -r ebe9914c0d1c -r 462012cf340c f
--- a/f Thu Jan 01 00:00:01 1970 +0000
+++ b/f Thu Jan 01 00:00:02 1970 +0000
@@ -1,1 +1,1 @@
-mq1r1
+mq1r1mq2
Adding one git-style patch and one normal:
$ hg qpop -a
popping f2.patch
popping f.patch
patch queue now empty
$ rm -fr .hg/patches
$ hg qinit -c
$ hg up -q 0
$ hg qnew --git f_git.patch -d '3 0'
$ echo mq1 > p
$ hg add p
$ hg qref --git -m 'P0 (git)'
$ hg qnew f.patch -d '4 0'
$ echo mq2 > p
$ hg qref -m P1
$ hg qci -m 'save patch state'
$ hg qseries -s
f_git.patch: P0 (git)
f.patch: P1
$ hg -R .hg/patches manifest
.hgignore
f.patch
f_git.patch
series
$ cat .hg/patches/f_git.patch
Date: 3 0
P0 (git)
diff --git a/p b/p
new file mode 100644
--- /dev/null
+++ b/p
@@ -0,0 +1,1 @@
+mq1
$ cat .hg/patches/f.patch
Date: 4 0
P1
diff -r ???????????? p (glob)
--- a/p ??? ??? ?? ??:??:?? ???? ????? (glob)
+++ b/p ??? ??? ?? ??:??:?? ???? ????? (glob)
@@ -1,1 +1,1 @@
-mq1
+mq2
Rebase the applied mq patches:
$ hg rebase -s 2 -d 1
rebasing 2:0c587ffcb480 f_git.patch qbase "P0 (git)"
rebasing 3:c7f18665e4bc f.patch qtip tip "P1"
saved backup bundle to $TESTTMP/a/.hg/strip-backup/0c587ffcb480-0ea5695f-rebase.hg
$ hg qci -m 'save patch state'
$ hg qseries -s
f_git.patch: P0 (git)
f.patch: P1
$ hg -R .hg/patches manifest
.hgignore
f.patch
f_git.patch
series
$ cat .hg/patches/f_git.patch
# HG changeset patch
# User test
# Date 3 0
# Thu Jan 01 00:00:03 1970 +0000
# Node ID 12d9f6a3bbe560dee50c7c454d434add7fb8e837
# Parent bac9ed9960d8992bcad75864a879fa76cadaf1b0
P0 (git)
diff --git a/p b/p
new file mode 100644
--- /dev/null
+++ b/p
@@ -0,0 +1,1 @@
+mq1
$ cat .hg/patches/f.patch
# HG changeset patch
# User test
# Date 4 0
# Thu Jan 01 00:00:04 1970 +0000
# Node ID c77a2661c64c60d82f63c4f7aefd95b3a948a557
# Parent 12d9f6a3bbe560dee50c7c454d434add7fb8e837
P1
diff -r 12d9f6a3bbe5 -r c77a2661c64c p
--- a/p Thu Jan 01 00:00:03 1970 +0000
+++ b/p Thu Jan 01 00:00:04 1970 +0000
@@ -1,1 +1,1 @@
-mq1
+mq2
$ cd ..
Rebase with guards
$ hg init foo
$ cd foo
$ echo a > a
$ hg ci -Am a
adding a
Create mq repo with guarded patches foo and bar and empty patch:
$ hg qinit
$ echo guarded > guarded
$ hg add guarded
$ hg qnew guarded
$ hg qnew empty-important -m 'important commit message' -d '1 0'
$ echo bar > bar
$ hg add bar
$ hg qnew bar -d '2 0'
$ echo foo > foo
$ hg add foo
$ hg qnew foo
$ hg qpop -a
popping foo
popping bar
popping empty-important
popping guarded
patch queue now empty
$ hg qguard guarded +guarded
$ hg qguard bar +baz
$ hg qguard foo +baz
$ hg qselect baz
number of unguarded, unapplied patches has changed from 1 to 3
$ hg qpush bar
applying empty-important
patch empty-important is empty
applying bar
now at: bar
$ hg qguard -l
guarded: +guarded
empty-important: unguarded
bar: +baz
foo: +baz
$ hg tglog
@ 2: 4f44b861d38c 'imported patch bar' tags: bar qtip tip
|
o 1: 0aaf4c3af7eb 'important commit message' tags: empty-important qbase
|
o 0: cb9a9f314b8b 'a' tags: qparent
Create new head to rebase bar onto:
$ hg up -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo b > b
$ hg add b
$ hg ci -m b
created new head
$ hg up -C 2
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo a >> a
$ hg qref
$ hg tglog
@ 3: d526d4536ed6 '[mq]: bar' tags: bar qtip tip
|
| o 2: d2ae7f538514 'b' tags:
| |
o | 1: 0aaf4c3af7eb 'important commit message' tags: empty-important qbase
|/
o 0: cb9a9f314b8b 'a' tags: qparent
Rebase bar (make sure series order is preserved and empty-important also is
removed from the series):
$ hg qseries
guarded
empty-important
bar
foo
$ [ -f .hg/patches/empty-important ]
$ hg -q rebase -d 2
note: not rebasing 1:0aaf4c3af7eb empty-important qbase "important commit message", its destination already has all its changes
$ hg qseries
guarded
bar
foo
$ [ -f .hg/patches/empty-important ]
[1]
$ hg qguard -l
guarded: +guarded
bar: +baz
foo: +baz
$ hg tglog
@ 2: 477d948bb2af '[mq]: bar' tags: bar qbase qtip tip
|
o 1: d2ae7f538514 'b' tags: qparent
|
o 0: cb9a9f314b8b 'a' tags:
$ cd ..