view tests/test-http-bundle1.t @ 42044:bb271ec2fbfb

compression: introduce a `storage.revlog.zstd.level` configuration

This option control the zstd compression level used when compressing revlog
chunk. The usage of zstd for revlog compression has not graduated from
experimental yet, but we intend to fix that soon.

The option name for the compression level is more straight forward to pick, so
this changesets comes first.  Having a dedicated option for each compression
engine is useful because they don't support the same range of values.

I ran the same measurement as for the zlib compression level (in the parent
changesets). The variation in repository size is stay mostly in the same (small)
range. The "read/write" performance see smallish variation, but are overall much
better than zlib. Write performance show the same tend of having better write
performance for when reaching high-end compression.

Again, we don't intend to change the default zstd compression level (currently:
3) in this series. However this is worth investigating in the future.

The Performance comparison of zlib vs zstd is quite impressive. The repository
size stay in the same range, but the performance are much better in all
situations.

Comparison summary
==================

We are looking at:
- performance range for zlib
- performance range for zstd
- comparison of default zstd (level-3) to default zlib (level 6)
- comparison of the slowest zstd time to the fastest zlib time

Read performance:
-----------------
          |           zlib          |           zstd          | cmp | f2s
mercurial |   0.170159 -   0.189219 |   0.144127 -   0.149624 | 80% | 88%
pypy      |   2.679217 -   2.768691 |   1.532317 -   1.705044 | 60% | 63%
netbeans  | 122.477027 - 141.620281 |  72.996346 -  89.731560 | 58% | 73%
mozilla   | 147.867662 - 170.572118 |  91.700995 - 105.853099 | 56% | 71%

Write performance:
------------------
          |           zlib          |           zstd          | cmp | f2s
mercurial |  53.250304 - 56.2936129 |  40.877025 -  45.677286 | 75% | 86%
pypy      | 460.721984 - 476.589918 | 270.545409 - 301.002219 | 63% | 65%
netbeans  | 520.560316 - 715.930400 | 370.356311 - 428.329652 | 55% | 82%
mozilla   | 739.803002 - 987.056093 | 505.152906 - 591.930683 | 57% | 80%

Raw data
--------

repo      alg lvl  .hg/store size  00manifest.d read       write

mercurial zlib  1      49,402,813     5,963,475   0.170159  53.250304
mercurial zlib  6      47,197,397     5,875,730   0.182820  56.264320
mercurial zlib  9      47,121,596     5,849,781   0.189219  56.293612

mercurial zstd  1      49,737,084     5,966,355   0.144127  40.877025
mercurial zstd  3      48,961,867     5,895,208   0.146376  42.268142
mercurial zstd  5      48,200,592     5,938,676   0.149624  43.162875
mercurial zstd 10      47,833,520     5,913,353   0.145185  44.012489
mercurial zstd 15      47,314,604     5,728,679   0.147686  45.677286
mercurial zstd 20      47,330,502     5,830,539   0.145789  45.025407
mercurial zstd 22      47,330,076     5,830,539   0.143996  44.690460


pypy      zlib  1     370,830,572    28,462,425   2.679217 460.721984
pypy      zlib  6     340,112,317    27,648,747   2.768691 467.537158
pypy      zlib  9     338,360,736    27,639,003   2.763495 476.589918

pypy      zstd  1     362,377,479    27,916,214   1.532317 270.545409
pypy      zstd  3     354,137,693    27,905,988   1.686718 294.951509
pypy      zstd  5     342,640,043    27,655,774   1.705044 301.002219
pypy      zstd 10     334,224,327    27,164,493   1.567287 285.186239
pypy      zstd 15     329,000,363    26,645,965   1.637729 299.561332
pypy      zstd 20     324,534,039    26,199,547   1.526813 302.149827
pypy      zstd 22     324,530,595    26,198,932   1.525718 307.821218


netbeans  zlib  1   1,281,847,810   165,495,457 122.477027 520.560316
netbeans  zlib  6   1,205,284,353   159,161,207 139.876147 715.930400
netbeans  zlib  9   1,197,135,671   155,034,586 141.620281 678.297064

netbeans  zstd  1   1,259,581,737   160,840,613  72.996346 370.356311
netbeans  zstd  3   1,232,978,122   157,691,551  81.622317 396.733087
netbeans  zstd  5   1,208,034,075   160,246,880  83.080549 364.342626
netbeans  zstd 10   1,188,624,176   156,083,417  79.323935 403.594602
netbeans  zstd 15   1,176,973,589   153,859,477  89.731560 428.329652
netbeans  zstd 20   1,162,958,258   151,147,535  82.842667 392.335349
netbeans  zstd 22   1,162,707,029   151,150,220  82.565695 402.840655


mozilla   zlib  1   2,775,497,186   298,527,987 147.867662 751.263721
mozilla   zlib  6   2,596,856,420   286,597,671 170.572118 987.056093
mozilla   zlib  9   2,587,542,494   287,018,264 163.622338 739.803002

mozilla   zstd  1   2,723,159,348   286,617,532  91.700995 570.042751
mozilla   zstd  3   2,665,055,001   286,152,013  95.240155 561.412805
mozilla   zstd  5   2,607,819,817   288,060,030 101.978048 505.152906
mozilla   zstd 10   2,558,761,085   283,967,648 104.113481 497.771202
mozilla   zstd 15   2,526,216,060   275,581,300 105.853099 591.930683
mozilla   zstd 20   2,485,114,806   266,478,859  95.268795 576.515389
mozilla   zstd 22   2,484,869,080   266,456,505  94.429282 572.785537

#require serve

This test is a duplicate of 'test-http.t', feel free to factor out
parts that are not bundle1/bundle2 specific.

  $ cat << EOF >> $HGRCPATH
  > [devel]
  > # This test is dedicated to interaction through old bundle
  > legacy.exchange = bundle1
  > EOF

  $ hg init test
  $ cd test
  $ echo foo>foo
  $ mkdir foo.d foo.d/bAr.hg.d foo.d/baR.d.hg
  $ echo foo>foo.d/foo
  $ echo bar>foo.d/bAr.hg.d/BaR
  $ echo bar>foo.d/baR.d.hg/bAR
  $ hg commit -A -m 1
  adding foo
  adding foo.d/bAr.hg.d/BaR
  adding foo.d/baR.d.hg/bAR
  adding foo.d/foo
  $ hg serve -p $HGPORT -d --pid-file=../hg1.pid -E ../error.log
  $ hg serve --config server.uncompressed=False -p $HGPORT1 -d --pid-file=../hg2.pid

Test server address cannot be reused

  $ hg serve -p $HGPORT1 2>&1
  abort: cannot start server at 'localhost:$HGPORT1': $EADDRINUSE$
  [255]

  $ cd ..
  $ cat hg1.pid hg2.pid >> $DAEMON_PIDS

clone via stream

#if no-reposimplestore
  $ hg clone --stream http://localhost:$HGPORT/ copy 2>&1
  streaming all changes
  6 files to transfer, 606 bytes of data
  transferred * bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg verify -R copy
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 4 changes to 4 files
#endif

try to clone via stream, should use pull instead

  $ hg clone --stream http://localhost:$HGPORT1/ copy2
  warning: stream clone requested but server has them disabled
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 4 changes to 4 files
  new changesets 8b6053c928fe
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved

try to clone via stream but missing requirements, so should use pull instead

  $ cat > $TESTTMP/removesupportedformat.py << EOF
  > from mercurial import localrepo
  > def extsetup(ui):
  >     localrepo.localrepository.supportedformats.remove(b'generaldelta')
  > EOF

  $ hg clone --config extensions.rsf=$TESTTMP/removesupportedformat.py --stream http://localhost:$HGPORT/ copy3
  warning: stream clone requested but client is missing requirements: generaldelta
  (see https://www.mercurial-scm.org/wiki/MissingRequirement for more information)
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 4 changes to 4 files
  new changesets 8b6053c928fe
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved

clone via pull

  $ hg clone http://localhost:$HGPORT1/ copy-pull
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 4 changes to 4 files
  new changesets 8b6053c928fe
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg verify -R copy-pull
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 4 changes to 4 files
  $ cd test
  $ echo bar > bar
  $ hg commit -A -d '1 0' -m 2
  adding bar
  $ cd ..

clone over http with --update

  $ hg clone http://localhost:$HGPORT1/ updated --update 0
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 5 changes to 5 files
  new changesets 8b6053c928fe:5fed3813f7f5
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -r . -R updated
  changeset:   0:8b6053c928fe
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  $ rm -rf updated

incoming via HTTP

  $ hg clone http://localhost:$HGPORT1/ --rev 0 partial
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 4 changes to 4 files
  new changesets 8b6053c928fe
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd partial
  $ touch LOCAL
  $ hg ci -qAm LOCAL
  $ hg incoming http://localhost:$HGPORT1/ --template '{desc}\n'
  comparing with http://localhost:$HGPORT1/
  searching for changes
  2
  $ cd ..

pull

  $ cd copy-pull
  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > changegroup = sh -c "printenv.py --line changegroup"
  > EOF
  $ hg pull
  pulling from http://localhost:$HGPORT1/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 5fed3813f7f5
  changegroup hook: HG_HOOKNAME=changegroup
  HG_HOOKTYPE=changegroup
  HG_NODE=5fed3813f7f5e1824344fdc9cf8f63bb662c292d
  HG_NODE_LAST=5fed3813f7f5e1824344fdc9cf8f63bb662c292d
  HG_SOURCE=pull
  HG_TXNID=TXN:$ID$
  HG_TXNNAME=pull
  http://localhost:$HGPORT1/
  HG_URL=http://localhost:$HGPORT1/
  
  (run 'hg update' to get a working copy)
  $ cd ..

clone from invalid URL

  $ hg clone http://localhost:$HGPORT/bad
  abort: HTTP Error 404: Not Found
  [255]

test http authentication
+ use the same server to test server side streaming preference

  $ cd test

  $ hg serve --config extensions.x=$TESTDIR/httpserverauth.py -p $HGPORT2 -d \
  >    --pid-file=pid --config server.preferuncompressed=True \
  >    --config web.push_ssl=False --config web.allow_push=* -A ../access.log
  $ cat pid >> $DAEMON_PIDS

  $ cat << EOF > get_pass.py
  > import getpass
  > def newgetpass(arg):
  >   return "pass"
  > getpass.getpass = newgetpass
  > EOF

  $ hg id http://localhost:$HGPORT2/
  abort: http authorization required for http://localhost:$HGPORT2/
  [255]
  $ hg id http://localhost:$HGPORT2/
  abort: http authorization required for http://localhost:$HGPORT2/
  [255]
  $ hg id --config ui.interactive=true --config extensions.getpass=get_pass.py http://user@localhost:$HGPORT2/
  http authorization required for http://localhost:$HGPORT2/
  realm: mercurial
  user: user
  password: 5fed3813f7f5
  $ hg id http://user:pass@localhost:$HGPORT2/
  5fed3813f7f5
  $ echo '[auth]' >> .hg/hgrc
  $ echo 'l.schemes=http' >> .hg/hgrc
  $ echo 'l.prefix=lo' >> .hg/hgrc
  $ echo 'l.username=user' >> .hg/hgrc
  $ echo 'l.password=pass' >> .hg/hgrc
  $ hg id http://localhost:$HGPORT2/
  5fed3813f7f5
  $ hg id http://localhost:$HGPORT2/
  5fed3813f7f5
  $ hg id http://user@localhost:$HGPORT2/
  5fed3813f7f5

#if no-reposimplestore
  $ hg clone http://user:pass@localhost:$HGPORT2/ dest 2>&1
  streaming all changes
  7 files to transfer, 916 bytes of data
  transferred * bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found
  updating to branch default
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
#endif

--pull should override server's preferuncompressed

  $ hg clone --pull http://user:pass@localhost:$HGPORT2/ dest-pull 2>&1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 5 changes to 5 files
  new changesets 8b6053c928fe:5fed3813f7f5
  updating to branch default
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg id http://user2@localhost:$HGPORT2/
  abort: http authorization required for http://localhost:$HGPORT2/
  [255]
  $ hg id http://user:pass2@localhost:$HGPORT2/
  abort: HTTP Error 403: no
  [255]

  $ hg -R dest-pull tag -r tip top
  $ hg -R dest-pull push http://user:pass@localhost:$HGPORT2/
  pushing to http://user:***@localhost:$HGPORT2/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  $ hg rollback -q

  $ sed 's/.*] "/"/' < ../access.log
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=capabilities HTTP/1.1" 401 - (no-reposimplestore !)
  "GET /?cmd=capabilities HTTP/1.1" 200 - (no-reposimplestore !)
  "GET /?cmd=branchmap HTTP/1.1" 200 - x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (no-reposimplestore !)
  "GET /?cmd=stream_out HTTP/1.1" 200 - x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (no-reposimplestore !)
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (no-reposimplestore !)
  "GET /?cmd=batch HTTP/1.1" 200 - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D5fed3813f7f5e1824344fdc9cf8f63bb662c292d x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (no-reposimplestore !)
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (no-reposimplestore !)
  "GET /?cmd=capabilities HTTP/1.1" 401 - (no-reposimplestore !)
  "GET /?cmd=capabilities HTTP/1.1" 200 - (no-reposimplestore !)
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (no-reposimplestore !)
  "GET /?cmd=batch HTTP/1.1" 200 - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=getbundle HTTP/1.1" 200 - x-hgarg-1:common=0000000000000000000000000000000000000000&heads=5fed3813f7f5e1824344fdc9cf8f63bb662c292d x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 403 -
  "GET /?cmd=capabilities HTTP/1.1" 401 -
  "GET /?cmd=capabilities HTTP/1.1" 200 -
  "GET /?cmd=batch HTTP/1.1" 200 - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D7f4e523d01f2cc3765ac8934da3d14db775ff872 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=branchmap HTTP/1.1" 200 - x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull
  "POST /?cmd=unbundle HTTP/1.1" 200 - x-hgarg-1:heads=686173686564+5eb5abfefeea63c80dd7553bcc3783f37e0c5524* (glob)
  "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull

  $ cd ..

clone of serve with repo in root and unserved subrepo (issue2970)

  $ hg --cwd test init sub
  $ echo empty > test/sub/empty
  $ hg --cwd test/sub add empty
  $ hg --cwd test/sub commit -qm 'add empty'
  $ hg --cwd test/sub tag -r 0 something
  $ echo sub = sub > test/.hgsub
  $ hg --cwd test add .hgsub
  $ hg --cwd test commit -qm 'add subrepo'
  $ hg clone http://localhost:$HGPORT noslash-clone
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 7 changes to 7 files
  new changesets 8b6053c928fe:56f9bc90cce6
  updating to branch default
  cloning subrepo sub from http://localhost:$HGPORT/sub
  abort: HTTP Error 404: Not Found
  [255]
  $ hg clone http://localhost:$HGPORT/ slash-clone
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 7 changes to 7 files
  new changesets 8b6053c928fe:56f9bc90cce6
  updating to branch default
  cloning subrepo sub from http://localhost:$HGPORT/sub
  abort: HTTP Error 404: Not Found
  [255]

check error log

  $ cat error.log

Check error reporting while pulling/cloning

  $ $RUNTESTDIR/killdaemons.py
  $ hg serve -R test -p $HGPORT -d --pid-file=hg3.pid -E error.log --config extensions.crash=${TESTDIR}/crashgetbundler.py
  $ cat hg3.pid >> $DAEMON_PIDS
  $ hg clone http://localhost:$HGPORT/ abort-clone
  requesting all changes
  abort: remote error:
  this is an exercise
  [255]
  $ cat error.log

disable pull-based clones

  $ hg serve -R test -p $HGPORT1 -d --pid-file=hg4.pid -E error.log --config server.disablefullbundle=True
  $ cat hg4.pid >> $DAEMON_PIDS
  $ hg clone http://localhost:$HGPORT1/ disable-pull-clone
  requesting all changes
  abort: remote error:
  server has pull-based clones disabled
  [255]

#if no-reposimplestore
... but keep stream clones working

  $ hg clone --stream --noupdate http://localhost:$HGPORT1/ test-stream-clone
  streaming all changes
  * files to transfer, * of data (glob)
  transferred * in * seconds (* KB/sec) (glob)
  searching for changes
  no changes found
#endif

... and also keep partial clones and pulls working
  $ hg clone http://localhost:$HGPORT1 --rev 0 test-partial-clone
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 4 changes to 4 files
  new changesets 8b6053c928fe
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg pull -R test-partial-clone
  pulling from http://localhost:$HGPORT1/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 3 changes to 3 files
  new changesets 5fed3813f7f5:56f9bc90cce6
  (run 'hg update' to get a working copy)

  $ cat error.log