view tests/test-histedit-fold.t @ 44950:f9734b2d59cc

py3: make stdout line-buffered if connected to a TTY

Status messages that are to be shown on the terminal should be written to the
file descriptor before anything further is done, to keep the user updated.

One common way to achieve this is to make stdout line-buffered if it is
connected to a TTY. This is done on Python 2 (except on Windows, where libc,
which the CPython 2 streams depend on, does not properly support this).

Python 3 rolls it own I/O streams. On Python 3, buffered binary streams can't be
set line-buffered. The previous code (added in 227ba1afcb65) incorrectly
assumed that on Python 3, pycompat.stdout (sys.stdout.buffer) is already
line-buffered. However the interpreter initializes it with a block-buffered
stream or an unbuffered stream (when the -u option or the PYTHONUNBUFFERED
environment variable is set), never with a line-buffered stream.

One example where the current behavior is unacceptable is when running
`hg pull https://www.mercurial-scm.org/repo/hg` on Python 3, where the line
"pulling from https://www.mercurial-scm.org/repo/hg" does not appear on the
terminal before the hg process blocks while waiting for the server.

Various approaches to fix this problem are possible, including:

1. Weaken the contract of procutil.stdout to not give any guarantees about
   buffering behavior. In this case, users of procutil.stdout need to be
   changed to do enough flushes. In particular,
  1. either ui must insert enough flushes for ui.write() and friends, or
  2. ui.write() and friends get split into flushing and fully buffered
     methods, or
  3. users of ui.write() and friends must flush explicitly.
2. Make stdout unbuffered.
3. Make stdout line-buffered. Since Python 3 does not natively support that for
   binary streams, we must implement it ourselves.

(2.) is problematic because using unbuffered I/O changes the performance
characteristics significantly compared to line-buffered (which is used on
Python 2) and this would be a regression.

(1.2.) and (1.3) are a substantial amount of work. It’s unclear whether the
added complexity would be justified, given that raw performance doesn’t matter
that much when writing to a terminal much faster than the user could read it.

(1.1.) pushes complexity into the ui class instead of separating the concern of
how stdout is buffered. Other users of procutil.stdout would still need to take
care of the flushes.

This patch implements (3.). The general performance considerations are very
similar to (1.1.). The extra method invocation and method forwarding add a
little more overhead if the class is used. In exchange, it doesn’t add overhead
if not used.


For the benchmarks, I compared the previous implementation (incorrect on Python
3), (1.1.), (3.) and (2.). The command was chosen so that the streams were
configured as if they were writing to a TTY, but actually write to a pager,
which is also the default:
HGRCPATH=/dev/null python3 ./hg --cwd ~/vcs/mozilla-central --time --pager yes --config pager.pager='cat > /dev/null' status --all

previous:
time: real 7.880 secs (user 7.290+0.050 sys 0.580+0.170)
time: real 7.830 secs (user 7.220+0.070 sys 0.590+0.140)
time: real 7.800 secs (user 7.210+0.050 sys 0.570+0.170)

(1.1.) using Yuya Nishihara’s patch:
time: real 9.860 secs (user 8.670+0.350 sys 1.160+0.830)
time: real 9.540 secs (user 8.430+0.370 sys 1.100+0.770)
time: real 9.830 secs (user 8.630+0.370 sys 1.180+0.840)

(3.) using this patch:
time: real 9.580 secs (user 8.480+0.350 sys 1.090+0.770)
time: real 9.670 secs (user 8.480+0.330 sys 1.170+0.860)
time: real 9.640 secs (user 8.500+0.350 sys 1.130+0.810)

(2.) using a previous patch by me:
time: real 10.480 secs (user 8.850+0.720 sys 1.590+1.500)
time: real 10.490 secs (user 8.750+0.750 sys 1.710+1.470)
time: real 10.240 secs (user 8.600+0.700 sys 1.590+1.510)


As expected, there’s no difference on Python 2, as exactly the same code paths
are used:

previous:
time: real 6.950 secs (user 5.870+0.330 sys 1.070+0.770)
time: real 7.040 secs (user 6.040+0.360 sys 0.980+0.750)
time: real 7.070 secs (user 5.950+0.360 sys 1.100+0.760)

this patch:
time: real 7.010 secs (user 5.900+0.390 sys 1.070+0.730)
time: real 7.000 secs (user 5.850+0.350 sys 1.120+0.760)
time: real 7.000 secs (user 5.790+0.380 sys 1.170+0.710)

Test histedit extension: Fold commands
======================================

This test file is dedicated to testing the fold command in non conflicting
case.

Initialization
---------------


  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > logt = log --template '{rev}:{node|short} {desc|firstline}\n'
  > [extensions]
  > histedit=
  > mockmakedate = $TESTDIR/mockmakedate.py
  > EOF


Simple folding
--------------------
  $ addwithdate ()
  > {
  >     echo $1 > $1
  >     hg add $1
  >     hg ci -m $1 -d "$2 0"
  > }

  $ initrepo ()
  > {
  >     hg init r
  >     cd r
  >     addwithdate a 1
  >     addwithdate b 2
  >     addwithdate c 3
  >     addwithdate d 4
  >     addwithdate e 5
  >     addwithdate f 6
  > }

  $ initrepo

log before edit
  $ hg logt --graph
  @  5:178e35e0ce73 f
  |
  o  4:1ddb6c90f2ee e
  |
  o  3:532247a8969b d
  |
  o  2:ff2c9fa2018b c
  |
  o  1:97d72e5f12c7 b
  |
  o  0:8580ff50825a a
  

  $ hg histedit ff2c9fa2018b --commands - 2>&1 <<EOF | fixbundle
  > pick 1ddb6c90f2ee e
  > pick 178e35e0ce73 f
  > fold ff2c9fa2018b c
  > pick 532247a8969b d
  > EOF

log after edit
  $ hg logt --graph
  @  4:c4d7f3def76d d
  |
  o  3:575228819b7e f
  |
  o  2:505a591af19e e
  |
  o  1:97d72e5f12c7 b
  |
  o  0:8580ff50825a a
  

post-fold manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f


check histedit_source, including that it uses the later date, from the first changeset

  $ hg log --debug --rev 3
  changeset:   3:575228819b7e6ed69e8c0a6a383ee59a80db7358
  phase:       draft
  parent:      2:505a591af19eed18f560af827b9e03d2076773dc
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    3:81eede616954057198ead0b2c73b41d1f392829a
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  files+:      c f
  extra:       branch=default
  extra:       histedit_source=7cad1d7030207872dfd1c3a7cb430f24f2884086,ff2c9fa2018b15fa74b33363bda9527323e2a99f
  description:
  f
  ***
  c
  
  

rollup will fold without preserving the folded commit's message or date

  $ OLDHGEDITOR=$HGEDITOR
  $ HGEDITOR=false
  $ hg histedit 97d72e5f12c7 --commands - 2>&1 <<EOF | fixbundle
  > pick 97d72e5f12c7 b
  > roll 505a591af19e e
  > pick 575228819b7e f
  > pick c4d7f3def76d d
  > EOF

  $ HGEDITOR=$OLDHGEDITOR

log after edit
  $ hg logt --graph
  @  3:bab801520cec d
  |
  o  2:58c8f2bfc151 f
  |
  o  1:5d939c56c72e b
  |
  o  0:8580ff50825a a
  

description is taken from rollup target commit

  $ hg log --debug --rev 1
  changeset:   1:5d939c56c72e77e29f5167696218e2131a40f5cf
  phase:       draft
  parent:      0:8580ff50825a50c8f716709acdf8de0deddcd6ab
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    1:b5e112a3a8354e269b1524729f0918662d847c38
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  files+:      b e
  extra:       branch=default
  extra:       histedit_source=97d72e5f12c7e84f85064aa72e5a297142c36ed9,505a591af19eed18f560af827b9e03d2076773dc
  description:
  b
  
  

check saving last-message.txt

  $ cat > $TESTTMP/abortfolding.py <<EOF
  > from mercurial import util
  > def abortfolding(ui, repo, hooktype, **kwargs):
  >     ctx = repo[kwargs.get('node')]
  >     if set(ctx.files()) == {b'c', b'd', b'f'}:
  >         return True # abort folding commit only
  >     ui.warn(b'allow non-folding commit\\n')
  > EOF
  $ cat > .hg/hgrc <<EOF
  > [hooks]
  > pretxncommit.abortfolding = python:$TESTTMP/abortfolding.py:abortfolding
  > EOF

  $ cat > $TESTTMP/editor.sh << EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > echo "check saving last-message.txt" >> \$1
  > EOF

  $ rm -f .hg/last-message.txt
  $ hg status --rev '58c8f2bfc151^1::bab801520cec'
  A c
  A d
  A f
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg histedit 58c8f2bfc151 --commands - 2>&1 <<EOF
  > pick 58c8f2bfc151 f
  > fold bab801520cec d
  > EOF
  allow non-folding commit
  ==== before editing
  f
  ***
  c
  ***
  d
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added c
  HG: added d
  HG: added f
  ====
  transaction abort!
  rollback completed
  abort: pretxncommit.abortfolding hook failed
  [255]

  $ cat .hg/last-message.txt
  f
  ***
  c
  ***
  d
  
  
  
  check saving last-message.txt

  $ cd ..
  $ rm -r r

folding preserves initial author but uses later date
----------------------------------------------------

  $ initrepo

  $ hg ci -d '7 0' --user "someone else" --amend --quiet

tip before edit
  $ hg log --rev .
  changeset:   5:10c36dd37515
  tag:         tip
  user:        someone else
  date:        Thu Jan 01 00:00:07 1970 +0000
  summary:     f
  

  $ hg --config progress.debug=1 --debug \
  > histedit 1ddb6c90f2ee --commands - 2>&1 <<EOF | \
  > egrep 'editing|unresolved'
  > pick 1ddb6c90f2ee e
  > fold 10c36dd37515 f
  > EOF
  editing: pick 1ddb6c90f2ee 4 e 1/2 changes (50.00%)
  editing: fold 10c36dd37515 5 f 2/2 changes (100.00%)

tip after edit, which should use the later date, from the second changeset
  $ hg log --rev .
  changeset:   4:e4f3ec5d0b40
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:07 1970 +0000
  summary:     e
  

  $ cd ..
  $ rm -r r

folding and creating no new change doesn't break:
-------------------------------------------------

folded content is dropped during a merge. The folded commit should properly disappear.

  $ mkdir fold-to-empty-test
  $ cd fold-to-empty-test
  $ hg init
  $ printf "1\n2\n3\n" > file
  $ hg add file
  $ hg commit -m '1+2+3'
  $ echo 4 >> file
  $ hg commit -m '+4'
  $ echo 5 >> file
  $ hg commit -m '+5'
  $ echo 6 >> file
  $ hg commit -m '+6'
  $ hg logt --graph
  @  3:251d831eeec5 +6
  |
  o  2:888f9082bf99 +5
  |
  o  1:617f94f13c0f +4
  |
  o  0:0189ba417d34 1+2+3
  

  $ hg histedit 1 --commands - << EOF
  > pick 617f94f13c0f 1 +4
  > drop 888f9082bf99 2 +5
  > fold 251d831eeec5 3 +6
  > EOF
  merging file
  warning: conflicts while merging file! (edit, then use 'hg resolve --mark')
  Fix up the change (fold 251d831eeec5)
  (hg histedit --continue to resume)
  [1]
There were conflicts, we keep P1 content. This
should effectively drop the changes from +6.

  $ hg status -v
  M file
  ? file.orig
  # The repository is in an unfinished *histedit* state.
  
  # Unresolved merge conflicts:
  # 
  #     file
  # 
  # To mark files as resolved:  hg resolve --mark FILE
  
  # To continue:    hg histedit --continue
  # To abort:       hg histedit --abort
  
  $ hg resolve -l
  U file
  $ hg revert -r 'p1()' file
  $ hg resolve --mark file
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue
  251d831eeec5: empty changeset
  saved backup bundle to $TESTTMP/fold-to-empty-test/.hg/strip-backup/888f9082bf99-daa0b8b3-histedit.hg
  $ hg logt --graph
  @  1:617f94f13c0f +4
  |
  o  0:0189ba417d34 1+2+3
  

  $ cd ..


Test fold through dropped
-------------------------


Test corner case where folded revision is separated from its parent by a
dropped revision.


  $ hg init fold-with-dropped
  $ cd fold-with-dropped
  $ printf "1\n2\n3\n" > file
  $ hg commit -Am '1+2+3'
  adding file
  $ echo 4 >> file
  $ hg commit -m '+4'
  $ echo 5 >> file
  $ hg commit -m '+5'
  $ echo 6 >> file
  $ hg commit -m '+6'
  $ hg logt -G
  @  3:251d831eeec5 +6
  |
  o  2:888f9082bf99 +5
  |
  o  1:617f94f13c0f +4
  |
  o  0:0189ba417d34 1+2+3
  
  $ hg histedit 1 --commands -  << EOF
  > pick 617f94f13c0f 1 +4
  > drop 888f9082bf99 2 +5
  > fold 251d831eeec5 3 +6
  > EOF
  merging file
  warning: conflicts while merging file! (edit, then use 'hg resolve --mark')
  Fix up the change (fold 251d831eeec5)
  (hg histedit --continue to resume)
  [1]
  $ cat > file << EOF
  > 1
  > 2
  > 3
  > 4
  > 5
  > EOF
  $ hg resolve --mark file
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg commit -m '+5.2'
  created new head
  $ echo 6 >> file
  $ HGEDITOR=cat hg histedit --continue
  +4
  ***
  +5.2
  ***
  +6
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: changed file
  saved backup bundle to $TESTTMP/fold-with-dropped/.hg/strip-backup/617f94f13c0f-3d69522c-histedit.hg
  $ hg logt -G
  @  1:10c647b2cdd5 +4
  |
  o  0:0189ba417d34 1+2+3
  
  $ hg export tip
  # HG changeset patch
  # User test
  # Date 0 0
  #      Thu Jan 01 00:00:00 1970 +0000
  # Node ID 10c647b2cdd54db0603ecb99b2ff5ce66d5a5323
  # Parent  0189ba417d34df9dda55f88b637dcae9917b5964
  +4
  ***
  +5.2
  ***
  +6
  
  diff -r 0189ba417d34 -r 10c647b2cdd5 file
  --- a/file	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,3 +1,6 @@
   1
   2
   3
  +4
  +5
  +6
  $ cd ..


Folding with initial rename (issue3729)
---------------------------------------

  $ hg init fold-rename
  $ cd fold-rename
  $ echo a > a.txt
  $ hg add a.txt
  $ hg commit -m a
  $ hg rename a.txt b.txt
  $ hg commit -m rename
  $ echo b >> b.txt
  $ hg commit -m b

  $ hg logt --follow b.txt
  2:e0371e0426bc b
  1:1c4f440a8085 rename
  0:6c795aa153cb a

  $ hg histedit 1c4f440a8085 --commands - 2>&1 << EOF | fixbundle
  > pick 1c4f440a8085 rename
  > fold e0371e0426bc b
  > EOF

  $ hg logt --follow b.txt
  1:cf858d235c76 rename
  0:6c795aa153cb a

  $ cd ..

Folding with swapping
---------------------

This is an excuse to test hook with histedit temporary commit (issue4422)


  $ hg init issue4422
  $ cd issue4422
  $ echo a > a.txt
  $ hg add a.txt
  $ hg commit -m a
  $ echo b > b.txt
  $ hg add b.txt
  $ hg commit -m b
  $ echo c > c.txt
  $ hg add c.txt
  $ hg commit -m c

  $ hg logt
  2:a1a953ffb4b0 c
  1:199b6bb90248 b
  0:6c795aa153cb a

  $ hg histedit 6c795aa153cb --config hooks.commit='echo commit $HG_NODE' --config hooks.tonative.commit=True \
  >     --commands - 2>&1 << EOF | fixbundle
  > pick 199b6bb90248 b
  > fold a1a953ffb4b0 c
  > pick 6c795aa153cb a
  > EOF
  commit 9599899f62c05f4377548c32bf1c9f1a39634b0c

  $ hg logt
  1:9599899f62c0 a
  0:79b99e9c8e49 b

Test unix -> windows style variable substitution in external hooks.

  $ cat > $TESTTMP/tmp.hgrc <<'EOF'
  > [hooks]
  > pre-add = echo no variables
  > post-add = echo ran $HG_ARGS, literal \$non-var, 'also $non-var', $HG_RESULT
  > tonative.post-add = True
  > EOF

  $ echo "foo" > amended.txt
  $ HGRCPATH=$TESTTMP/tmp.hgrc hg add -v amended.txt
  running hook pre-add: echo no variables
  no variables
  adding amended.txt
  converting hook "post-add" to native (windows !)
  running hook post-add: echo ran %HG_ARGS%, literal $non-var, "also $non-var", %HG_RESULT% (windows !)
  running hook post-add: echo ran $HG_ARGS, literal \$non-var, 'also $non-var', $HG_RESULT (no-windows !)
  ran add -v amended.txt, literal $non-var, "also $non-var", 0 (windows !)
  ran add -v amended.txt, literal $non-var, also $non-var, 0 (no-windows !)
  $ hg ci -q --config extensions.largefiles= --amend -I amended.txt
  The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)

Test that folding multiple changes in a row doesn't show multiple
editors.

  $ echo foo >> foo
  $ hg add foo
  $ hg ci -m foo1
  $ echo foo >> foo
  $ hg ci -m foo2
  $ echo foo >> foo
  $ hg ci -m foo3
  $ hg logt
  4:21679ff7675c foo3
  3:b7389cc4d66e foo2
  2:0e01aeef5fa8 foo1
  1:578c7455730c a
  0:79b99e9c8e49 b
  $ cat > "$TESTTMP/editor.sh" <<EOF
  > echo ran editor >> "$TESTTMP/editorlog.txt"
  > cat \$1 >> "$TESTTMP/editorlog.txt"
  > echo END >> "$TESTTMP/editorlog.txt"
  > echo merged foos > \$1
  > EOF
  $ HGEDITOR="sh \"$TESTTMP/editor.sh\"" hg histedit 1 --commands - 2>&1 <<EOF | fixbundle
  > pick 578c7455730c 1 a
  > pick 0e01aeef5fa8 2 foo1
  > fold b7389cc4d66e 3 foo2
  > fold 21679ff7675c 4 foo3
  > EOF
  merging foo
  $ hg logt
  2:e8bedbda72c1 merged foos
  1:578c7455730c a
  0:79b99e9c8e49 b
Editor should have run only once
  $ cat $TESTTMP/editorlog.txt
  ran editor
  foo1
  ***
  foo2
  ***
  foo3
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added foo
  END

  $ cd ..

Test rolling into a commit with multiple children (issue5498)

  $ hg init roll
  $ cd roll
  $ echo a > a
  $ hg commit -qAm aa
  $ echo b > b
  $ hg commit -qAm bb
  $ hg up -q ".^"
  $ echo c > c
  $ hg commit -qAm cc
  $ hg log -G -T '{node|short} {desc}'
  @  5db65b93a12b cc
  |
  | o  301d76bdc3ae bb
  |/
  o  8f0162e483d0 aa
  

  $ hg histedit . --commands - << EOF
  > r 5db65b93a12b
  > EOF
  hg: parse error: first changeset cannot use verb "roll"
  [255]
  $ hg log -G -T '{node|short} {desc}'
  @  5db65b93a12b cc
  |
  | o  301d76bdc3ae bb
  |/
  o  8f0162e483d0 aa
  

  $ cd ..

====================================
Test update-timestamp config option|
====================================

  $ addwithdate ()
  > {
  >     echo $1 > $1
  >     hg add $1
  >     hg ci -m $1 -d "$2 0"
  > }

  $ initrepo ()
  > {
  >     hg init r
  >     cd r
  >     addwithdate a 1
  >     addwithdate b 2
  >     addwithdate c 3
  >     addwithdate d 4
  >     addwithdate e 5
  >     addwithdate f 6
  > }

  $ initrepo

log before edit

  $ hg log
  changeset:   5:178e35e0ce73
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:06 1970 +0000
  summary:     f
  
  changeset:   4:1ddb6c90f2ee
  user:        test
  date:        Thu Jan 01 00:00:05 1970 +0000
  summary:     e
  
  changeset:   3:532247a8969b
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     d
  
  changeset:   2:ff2c9fa2018b
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  
  changeset:   1:97d72e5f12c7
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     b
  
  changeset:   0:8580ff50825a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

  $ hg histedit 1ddb6c90f2ee --commands - 2>&1 --config rewrite.update-timestamp=True <<EOF | fixbundle
  > pick 178e35e0ce73 f
  > fold 1ddb6c90f2ee e
  > EOF

log after edit
observe time from f is updated

  $ hg log
  changeset:   4:f7909b1863a2
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     f
  
  changeset:   3:532247a8969b
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     d
  
  changeset:   2:ff2c9fa2018b
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  
  changeset:   1:97d72e5f12c7
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     b
  
  changeset:   0:8580ff50825a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  
post-fold manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

  $ cd ..