procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> drawdag=$TESTDIR/drawdag.py
> [alias]
> tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
> EOF
$ hg init repo
$ cd repo
$ echo A > a
$ echo >> a
$ hg ci -Am A
adding a
$ echo B > a
$ echo >> a
$ hg ci -m B
$ echo C > a
$ echo >> a
$ hg ci -m C
$ hg up -q -C 0
$ echo D >> a
$ hg ci -Am AD
created new head
$ hg tglog
@ 3: 3878212183bd 'AD'
|
| o 2: 30ae917c0e4f 'C'
| |
| o 1: 0f4f7cb4f549 'B'
|/
o 0: 1e635d440a73 'A'
$ hg rebase -s 1 -d 3
rebasing 1:0f4f7cb4f549 "B"
merging a
rebasing 2:30ae917c0e4f "C"
merging a
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/0f4f7cb4f549-82b3b163-rebase.hg
$ hg tglog
o 3: 25773bc4b4b0 'C'
|
o 2: c09015405f75 'B'
|
@ 1: 3878212183bd 'AD'
|
o 0: 1e635d440a73 'A'
$ cd ..
Test rebasing of merges with ancestors of the rebase destination - a situation
that often happens when trying to recover from repeated merging with a mainline
branch.
The test case creates a dev branch that contains a couple of merges from the
default branch. When rebasing to the default branch, these merges would be
merges with ancestors on the same branch. The merges _could_ contain some
interesting conflict resolutions or additional changes in the merge commit, but
that is mixed up with the actual merge stuff and there is in general no way to
separate them.
$ hg init ancestor-merge
$ cd ancestor-merge
$ touch f-default
$ hg ci -Aqm 'default: create f-default'
$ hg branch -q dev
$ hg ci -qm 'dev: create branch'
$ echo stuff > f-dev
$ hg ci -Aqm 'dev: f-dev stuff'
$ hg up -q default
$ echo stuff > f-default
$ hg ci -m 'default: f-default stuff'
$ hg up -q dev
$ hg merge -q default
$ hg ci -m 'dev: merge default'
$ hg up -q default
$ hg rm f-default
$ hg ci -m 'default: remove f-default'
$ hg up -q dev
$ hg merge -q default
$ hg ci -m 'dev: merge default'
$ hg up -q default
$ echo stuff > f-other
$ hg ci -Aqm 'default: f-other stuff'
$ hg tglog
@ 7: e08089805d82 'default: f-other stuff'
|
| o 6: 010ced67e558 'dev: merge default' dev
|/|
o | 5: 462860db70a1 'default: remove f-default'
| |
| o 4: 4b019212aaf6 'dev: merge default' dev
|/|
o | 3: f157ecfd2b6b 'default: f-default stuff'
| |
| o 2: ec2c14fb2984 'dev: f-dev stuff' dev
| |
| o 1: 1d1a643d390e 'dev: create branch' dev
|/
o 0: e90e8eb90b6f 'default: create f-default'
$ hg clone -qU . ../ancestor-merge-2
Full rebase all the way back from branching point:
$ hg rebase -r 'only(dev,default)' -d default --config ui.interactive=True << EOF
> c
> EOF
rebasing 1:1d1a643d390e "dev: create branch"
note: not rebasing 1:1d1a643d390e "dev: create branch", its destination already has all its changes
rebasing 2:ec2c14fb2984 "dev: f-dev stuff"
rebasing 4:4b019212aaf6 "dev: merge default"
note: not rebasing 4:4b019212aaf6 "dev: merge default", its destination already has all its changes
rebasing 6:010ced67e558 "dev: merge default"
note: not rebasing 6:010ced67e558 "dev: merge default", its destination already has all its changes
saved backup bundle to $TESTTMP/ancestor-merge/.hg/strip-backup/1d1a643d390e-4a6f6d17-rebase.hg
$ hg tglog
o 4: 3e075b1c0a40 'dev: f-dev stuff'
|
@ 3: e08089805d82 'default: f-other stuff'
|
o 2: 462860db70a1 'default: remove f-default'
|
o 1: f157ecfd2b6b 'default: f-default stuff'
|
o 0: e90e8eb90b6f 'default: create f-default'
Grafty cherry picking rebasing:
$ cd ../ancestor-merge-2
$ hg phase -fdr0:
$ hg rebase -r 'children(only(dev,default))' -d default --config ui.interactive=True << EOF
> c
> EOF
rebasing 2:ec2c14fb2984 "dev: f-dev stuff"
rebasing 4:4b019212aaf6 "dev: merge default"
abort: rebasing 4:4b019212aaf6 will include unwanted changes from 1:1d1a643d390e
[10]
$ cd ..
Test order of parents of rebased merged with un-rebased changes as p1.
$ hg init parentorder
$ cd parentorder
$ touch f
$ hg ci -Aqm common
$ touch change
$ hg ci -Aqm change
$ touch target
$ hg ci -Aqm target
$ hg up -qr 0
$ touch outside
$ hg ci -Aqm outside
$ hg merge -qr 1
$ hg ci -m 'merge p1 3=outside p2 1=ancestor'
$ hg par
changeset: 4:6990226659be
tag: tip
parent: 3:f59da8fc0fcf
parent: 1:dd40c13f7a6f
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge p1 3=outside p2 1=ancestor
$ hg up -qr 1
$ hg merge -qr 3
$ hg ci -qm 'merge p1 1=ancestor p2 3=outside'
$ hg par
changeset: 5:a57575f79074
tag: tip
parent: 1:dd40c13f7a6f
parent: 3:f59da8fc0fcf
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge p1 1=ancestor p2 3=outside
$ hg tglog
@ 5: a57575f79074 'merge p1 1=ancestor p2 3=outside'
|\
+---o 4: 6990226659be 'merge p1 3=outside p2 1=ancestor'
| |/
| o 3: f59da8fc0fcf 'outside'
| |
+---o 2: a60552eb93fb 'target'
| |
o | 1: dd40c13f7a6f 'change'
|/
o 0: 02f0f58d5300 'common'
$ hg rebase -r 4 -d 2
rebasing 4:6990226659be "merge p1 3=outside p2 1=ancestor"
saved backup bundle to $TESTTMP/parentorder/.hg/strip-backup/6990226659be-4d67a0d3-rebase.hg
$ hg tip
changeset: 5:cca50676b1c5
tag: tip
parent: 2:a60552eb93fb
parent: 3:f59da8fc0fcf
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge p1 3=outside p2 1=ancestor
$ hg rebase -r 4 -d 2
rebasing 4:a57575f79074 "merge p1 1=ancestor p2 3=outside"
saved backup bundle to $TESTTMP/parentorder/.hg/strip-backup/a57575f79074-385426e5-rebase.hg
$ hg tip
changeset: 5:f9daf77ffe76
tag: tip
parent: 2:a60552eb93fb
parent: 3:f59da8fc0fcf
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: merge p1 1=ancestor p2 3=outside
$ hg tglog
@ 5: f9daf77ffe76 'merge p1 1=ancestor p2 3=outside'
|\
+---o 4: cca50676b1c5 'merge p1 3=outside p2 1=ancestor'
| |/
| o 3: f59da8fc0fcf 'outside'
| |
o | 2: a60552eb93fb 'target'
| |
o | 1: dd40c13f7a6f 'change'
|/
o 0: 02f0f58d5300 'common'
rebase of merge of ancestors
$ hg up -qr 2
$ hg merge -qr 3
$ echo 'other change while merging future "rebase ancestors"' > other
$ hg ci -Aqm 'merge rebase ancestors'
$ hg rebase -d 5 -v
rebasing 6:4c5f12f25ebe tip "merge rebase ancestors"
resolving manifests
removing other
resolving manifests
getting other
committing files:
other
committing manifest
committing changelog
rebase merging completed
1 changesets found
uncompressed size of bundle content:
199 (changelog)
216 (manifests)
182 other
saved backup bundle to $TESTTMP/parentorder/.hg/strip-backup/4c5f12f25ebe-f46990e5-rebase.hg
1 changesets found
uncompressed size of bundle content:
254 (changelog)
167 (manifests)
182 other
adding branch
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
rebase completed
$ hg tglog
@ 6: 113755df812b 'merge rebase ancestors'
|
o 5: f9daf77ffe76 'merge p1 1=ancestor p2 3=outside'
|\
+---o 4: cca50676b1c5 'merge p1 3=outside p2 1=ancestor'
| |/
| o 3: f59da8fc0fcf 'outside'
| |
o | 2: a60552eb93fb 'target'
| |
o | 1: dd40c13f7a6f 'change'
|/
o 0: 02f0f58d5300 'common'
Due to the limitation of 3-way merge algorithm (1 merge base), rebasing a merge
may include unwanted content:
$ hg init $TESTTMP/dual-merge-base1
$ cd $TESTTMP/dual-merge-base1
$ hg debugdrawdag <<'EOS'
> F
> /|
> D E
> | |
> B C
> |/
> A Z
> |/
> R
> EOS
$ hg rebase -r D+E+F -d Z
rebasing 5:5f2c926dfecf D "D"
rebasing 6:b296604d9846 E "E"
rebasing 7:caa9781e507d F tip "F"
abort: rebasing 7:caa9781e507d will include unwanted changes from 4:d6003a550c2c or 3:c1e6b162678d
[10]
The warning does not get printed if there is no unwanted change detected:
$ hg init $TESTTMP/dual-merge-base2
$ cd $TESTTMP/dual-merge-base2
$ hg debugdrawdag <<'EOS'
> D
> /|
> B C
> |/
> A Z
> |/
> R
> EOS
$ hg rebase -r B+C+D -d Z
rebasing 3:c1e6b162678d B "B"
rebasing 4:d6003a550c2c C "C"
rebasing 5:c8f78076273e D tip "D"
saved backup bundle to $TESTTMP/dual-merge-base2/.hg/strip-backup/d6003a550c2c-6f1424b6-rebase.hg
$ hg manifest -r 'desc(D)'
B
C
R
Z
The merge base could be different from old p1 (changed parent becomes new p1):
$ hg init $TESTTMP/chosen-merge-base1
$ cd $TESTTMP/chosen-merge-base1
$ hg debugdrawdag <<'EOS'
> F
> /|
> D E
> | |
> B C Z
> EOS
$ hg rebase -r D+F -d Z
rebasing 3:004dc1679908 D "D"
rebasing 5:4be4cbf6f206 F tip "F"
saved backup bundle to $TESTTMP/chosen-merge-base1/.hg/strip-backup/004dc1679908-06a66a3c-rebase.hg
$ hg manifest -r 'desc(F)'
C
D
E
Z
$ hg log -r `hg log -r 'desc(F)' -T '{p1node}'` -T '{desc}\n'
D
$ hg init $TESTTMP/chosen-merge-base2
$ cd $TESTTMP/chosen-merge-base2
$ hg debugdrawdag <<'EOS'
> F
> /|
> D E
> | |
> B C Z
> EOS
$ hg rebase -r E+F -d Z
rebasing 4:974e4943c210 E "E"
rebasing 5:4be4cbf6f206 F tip "F"
saved backup bundle to $TESTTMP/chosen-merge-base2/.hg/strip-backup/974e4943c210-b2874da5-rebase.hg
$ hg manifest -r 'desc(F)'
B
D
E
Z
$ hg log -r `hg log -r 'desc(F)' -T '{p1node}'` -T '{desc}\n'
E