annotate tests/test-lfs-test-server.t @ 37048:fc5e261915b9

wireproto: require POST for all HTTPv2 requests

Wire protocol version 1 transfers argument data via request
headers by default. This has historically caused problems because
servers institute limits on the length of individual HTTP headers
as well as the total size of all request headers. Mercurial servers
can advertise the maximum length of an individual header. But
there's no guarantee any intermediate HTTP agents will accept
headers up to that length.

In the existing wire protocol, server operators typically also
key off the HTTP request method to implement authentication.
For example, GET requests translate to read-only requests and
can be allowed. But read-write commands must use POST and require
authentication. This has typically worked because the only wire
protocol commands that use POST modify the repo (e.g. the
"unbundle" command).

There is an experimental feature to enable clients to transmit
argument data via POST request bodies. This is technically a
better and more robust solution. But we can't enable it by default
because of servers assuming POST means write access.

In version 2 of the wire protocol, the permissions of a request
are encoded in the URL. And with it being a new protocol in a new
URL space, we're not constrained by backwards compatibility
requirements.

This commit adopts the technically superior mechanism of using
HTTP request bodies to send argument data by requiring POST for
all commands. Strictly speaking, it may be possible to send
request bodies on GET requests. But my experience is that not all
HTTP stacks support this. POST pretty much always works. Using POST
for read-only operations does sacrifice some RESTful design
purity. But this API cares about practicality, not about being
in Roy T. Fielding's REST ivory tower.

There's a chance we may relax this restriction in the future. But
for now, I want to see how far we can get with a POST only API.

Differential Revision: https://phab.mercurial-scm.org/D2837

#require lfs-test-server

  $ LFS_LISTEN="tcp://:$HGPORT"
  $ LFS_HOST="localhost:$HGPORT"
  $ LFS_PUBLIC=1
  $ export LFS_LISTEN LFS_HOST LFS_PUBLIC
#if no-windows
  $ lfs-test-server &> lfs-server.log &
  $ echo $! >> $DAEMON_PIDS
#else
  $ cat >> $TESTTMP/spawn.py <<EOF
  > import os
  > import subprocess
  > import sys
  > 
  > for path in os.environ["PATH"].split(os.pathsep):
  >     exe = os.path.join(path, 'lfs-test-server.exe')
  >     if os.path.exists(exe):
  >         with open('lfs-server.log', 'wb') as out:
  >             p = subprocess.Popen(exe, stdout=out, stderr=out)
  >             sys.stdout.write('%s\n' % p.pid)
  >             sys.exit(0)
  > sys.exit(1)
  > EOF
  $ $PYTHON $TESTTMP/spawn.py >> $DAEMON_PIDS
#endif

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > lfs=
  > [lfs]
  > url=http://foo:bar@$LFS_HOST/
  > track=all()
  > EOF

  $ hg init repo1
  $ cd repo1
  $ echo THIS-IS-LFS > a
  $ hg commit -m a -A a

A push can be serviced directly from the usercache if it isn't in the local
store.

  $ hg init ../repo2
  $ mv .hg/store/lfs .hg/store/lfs_
  $ hg push ../repo2 --debug
  http auth: user foo, password ***
  pushing to ../repo2
  http auth: user foo, password ***
  query 1; heads
  searching for changes
  1 total queries in *s (glob)
  listing keys for "phases"
  checking for updated bookmarks
  listing keys for "bookmarks"
  lfs: computing set of blobs to upload
  Status: 200
  Content-Length: 309
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "upload": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b"
          }
        }, 
        "oid": "31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b", 
        "size": 12
      }
    ]
  }
  lfs: uploading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes)
  Status: 200
  Content-Length: 0
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b
  lfs: uploaded 1 files (12 bytes)
  1 changesets found
  list of changesets:
  99a7098854a3984a5c9eab0fc7a2906697b7cb5c
  bundle2-output-bundle: "HG20", 4 parts total
  bundle2-output-part: "replycaps" * bytes payload (glob)
  bundle2-output-part: "check:heads" streamed payload
  bundle2-output-part: "changegroup" (params: 1 mandatory) streamed payload
  bundle2-output-part: "phase-heads" 24 bytes payload
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "replycaps" supported
  bundle2-input-part: total payload size * (glob)
  bundle2-input-part: "check:heads" supported
  bundle2-input-part: total payload size 20
  bundle2-input-part: "changegroup" (params: 1 mandatory) supported
  adding changesets
  add changeset 99a7098854a3
  adding manifests
  adding file changes
  adding a revisions
  added 1 changesets with 1 changes to 1 files
  calling hook pretxnchangegroup.lfs: hgext.lfs.checkrequireslfs
  bundle2-input-part: total payload size 617
  bundle2-input-part: "phase-heads" supported
  bundle2-input-part: total payload size 24
  bundle2-input-bundle: 3 parts total
  updating the branch cache
  bundle2-output-bundle: "HG20", 1 parts total
  bundle2-output-part: "reply:changegroup" (advisory) (params: 0 advisory) empty payload
  bundle2-input-bundle: no-transaction
  bundle2-input-part: "reply:changegroup" (advisory) (params: 0 advisory) supported
  bundle2-input-bundle: 0 parts total
  listing keys for "phases"
  $ mv .hg/store/lfs_ .hg/store/lfs

Clear the cache to force a download
  $ rm -rf `hg config lfs.usercache`
  $ cd ../repo2
  $ hg update tip --debug
  http auth: user foo, password ***
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 000000000000, local: 000000000000+, remote: 99a7098854a3
  Status: 200
  Content-Length: 311
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b"
          }
        }, 
        "oid": "31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b", 
        "size": 12
      }
    ]
  }
  lfs: downloading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes)
  Status: 200
  Content-Length: 12
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b to the usercache
  lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b
   a: remote created -> g
  getting a
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

When the server has some blobs already

  $ hg mv a b
  $ echo ANOTHER-LARGE-FILE > c
  $ echo ANOTHER-LARGE-FILE2 > d
  $ hg commit -m b-and-c -A b c d
  $ hg push ../repo1 --debug
  http auth: user foo, password ***
  pushing to ../repo1
  http auth: user foo, password ***
  query 1; heads
  searching for changes
  all remote heads known locally
  listing keys for "phases"
  checking for updated bookmarks
  listing keys for "bookmarks"
  listing keys for "bookmarks"
  lfs: computing set of blobs to upload
  Status: 200
  Content-Length: 901
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b"
          }
        }, 
        "oid": "31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b", 
        "size": 12
      }, 
      {
        "actions": {
          "upload": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19"
          }
        }, 
        "oid": "37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19", 
        "size": 20
      }, 
      {
        "actions": {
          "upload": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998"
          }
        }, 
        "oid": "d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998", 
        "size": 19
      }
    ]
  }
  lfs: need to transfer 2 objects (39 bytes)
  lfs: uploading 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 (20 bytes)
  Status: 200
  Content-Length: 0
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: processed: 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19
  lfs: uploading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes)
  Status: 200
  Content-Length: 0
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  lfs: uploaded 2 files (39 bytes)
  1 changesets found
  list of changesets:
  dfca2c9e2ef24996aa61ba2abd99277d884b3d63
  bundle2-output-bundle: "HG20", 5 parts total
  bundle2-output-part: "replycaps" * bytes payload (glob)
  bundle2-output-part: "check:phases" 24 bytes payload
  bundle2-output-part: "check:heads" streamed payload
  bundle2-output-part: "changegroup" (params: 1 mandatory) streamed payload
  bundle2-output-part: "phase-heads" 24 bytes payload
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "replycaps" supported
  bundle2-input-part: total payload size * (glob)
  bundle2-input-part: "check:phases" supported
  bundle2-input-part: total payload size 24
  bundle2-input-part: "check:heads" supported
  bundle2-input-part: total payload size 20
  bundle2-input-part: "changegroup" (params: 1 mandatory) supported
  adding changesets
  add changeset dfca2c9e2ef2
  adding manifests
  adding file changes
  adding b revisions
  adding c revisions
  adding d revisions
  added 1 changesets with 3 changes to 3 files
  bundle2-input-part: total payload size 1315
  bundle2-input-part: "phase-heads" supported
  bundle2-input-part: total payload size 24
  bundle2-input-bundle: 4 parts total
  updating the branch cache
  bundle2-output-bundle: "HG20", 1 parts total
  bundle2-output-part: "reply:changegroup" (advisory) (params: 0 advisory) empty payload
  bundle2-input-bundle: no-transaction
  bundle2-input-part: "reply:changegroup" (advisory) (params: 0 advisory) supported
  bundle2-input-bundle: 0 parts total
  listing keys for "phases"

Clear the cache to force a download
  $ rm -rf `hg config lfs.usercache`
  $ hg --repo ../repo1 update tip --debug
  http auth: user foo, password ***
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 99a7098854a3, local: 99a7098854a3+, remote: dfca2c9e2ef2
  Status: 200
  Content-Length: 608
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19"
          }
        }, 
        "oid": "37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19", 
        "size": 20
      }, 
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998"
          }
        }, 
        "oid": "d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998", 
        "size": 19
      }
    ]
  }
  lfs: need to transfer 2 objects (39 bytes)
  lfs: downloading 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 (20 bytes)
  Status: 200
  Content-Length: 20
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 to the usercache
  lfs: processed: 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19
  lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes)
  Status: 200
  Content-Length: 19
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 to the usercache
  lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
   b: remote created -> g
  getting b
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
   c: remote created -> g
  getting c
  lfs: found d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 in the local lfs store
   d: remote created -> g
  getting d
  lfs: found 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 in the local lfs store
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

Test a corrupt file download, but clear the cache first to force a download.

  $ rm -rf `hg config lfs.usercache`
  $ cp $TESTTMP/lfs-content/d1/1e/1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 blob
  $ echo 'damage' > $TESTTMP/lfs-content/d1/1e/1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  $ rm ../repo1/.hg/store/lfs/objects/d1/1e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  $ rm ../repo1/*

  $ hg --repo ../repo1 update -C tip --debug
  http auth: user foo, password ***
  resolving manifests
   branchmerge: False, force: True, partial: False
   ancestor: dfca2c9e2ef2+, local: dfca2c9e2ef2+, remote: dfca2c9e2ef2
  Status: 200
  Content-Length: 311
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998"
          }
        }, 
        "oid": "d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998", 
        "size": 19
      }
    ]
  }
  lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes)
  Status: 200
  Content-Length: 7
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  abort: corrupt remote lfs object: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  [255]

The corrupted blob is not added to the usercache or local store

  $ test -f ../repo1/.hg/store/lfs/objects/d1/1e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  [1]
  $ test -f `hg config lfs.usercache`/d1/1e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  [1]
  $ cp blob $TESTTMP/lfs-content/d1/1e/1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998

Test a corrupted file upload

  $ echo 'another lfs blob' > b
  $ hg ci -m 'another blob'
  $ echo 'damage' > .hg/store/lfs/objects/e6/59058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0
  $ hg push --debug ../repo1
  http auth: user foo, password ***
  pushing to ../repo1
  http auth: user foo, password ***
  query 1; heads
  searching for changes
  all remote heads known locally
  listing keys for "phases"
  checking for updated bookmarks
  listing keys for "bookmarks"
  listing keys for "bookmarks"
  lfs: computing set of blobs to upload
  Status: 200
  Content-Length: 309
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "upload": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/e659058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0"
          }
        }, 
        "oid": "e659058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0", 
        "size": 17
      }
    ]
  }
  lfs: uploading e659058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0 (17 bytes)
  abort: detected corrupt lfs object: e659058e26b07b39d2a9c7145b3f99b41f797b6621c8076600e9cb7ee88291f0
  (run hg verify)
  [255]

Archive will prefetch blobs in a group

  $ rm -rf .hg/store/lfs `hg config lfs.usercache`
  $ hg archive --debug -r 1 ../archive
  http auth: user foo, password ***
  Status: 200
  Content-Length: 905
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b"
          }
        }, 
        "oid": "31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b", 
        "size": 12
      }, 
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19"
          }
        }, 
        "oid": "37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19", 
        "size": 20
      }, 
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998"
          }
        }, 
        "oid": "d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998", 
        "size": 19
      }
    ]
  }
  lfs: need to transfer 3 objects (51 bytes)
  lfs: downloading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes)
  Status: 200
  Content-Length: 12
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b to the usercache
  lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b
  lfs: downloading 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 (20 bytes)
  Status: 200
  Content-Length: 20
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 to the usercache
  lfs: processed: 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19
  lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes)
  Status: 200
  Content-Length: 19
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 to the usercache
  lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
  lfs: found d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 in the local lfs store
  lfs: found 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 in the local lfs store
  $ find ../archive | sort
  ../archive
  ../archive/.hg_archival.txt
  ../archive/a
  ../archive/b
  ../archive/c
  ../archive/d

Cat will prefetch blobs in a group

  $ rm -rf .hg/store/lfs `hg config lfs.usercache`
  $ hg cat --debug -r 1 a b c
  http auth: user foo, password ***
  Status: 200
  Content-Length: 608
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b"
          }
        }, 
        "oid": "31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b", 
        "size": 12
      }, 
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998"
          }
        }, 
        "oid": "d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998", 
        "size": 19
      }
    ]
  }
  lfs: need to transfer 2 objects (31 bytes)
  lfs: downloading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes)
  Status: 200
  Content-Length: 12
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b to the usercache
  lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b
  lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes)
  Status: 200
  Content-Length: 19
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 to the usercache
  lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
  THIS-IS-LFS
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
  THIS-IS-LFS
  lfs: found d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 in the local lfs store
  ANOTHER-LARGE-FILE

Revert will prefetch blobs in a group

  $ rm -rf .hg/store/lfs
  $ rm -rf `hg config lfs.usercache`
  $ rm *
  $ hg revert --all -r 1 --debug
  http auth: user foo, password ***
  adding a
  reverting b
  reverting c
  reverting d
  Status: 200
  Content-Length: 905
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b"
          }
        }, 
        "oid": "31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b", 
        "size": 12
      }, 
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19"
          }
        }, 
        "oid": "37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19", 
        "size": 20
      }, 
      {
        "actions": {
          "download": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998"
          }
        }, 
        "oid": "d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998", 
        "size": 19
      }
    ]
  }
  lfs: need to transfer 3 objects (51 bytes)
  lfs: downloading 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b (12 bytes)
  Status: 200
  Content-Length: 12
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b to the usercache
  lfs: processed: 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b
  lfs: downloading 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 (20 bytes)
  Status: 200
  Content-Length: 20
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 to the usercache
  lfs: processed: 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19
  lfs: downloading d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 (19 bytes)
  Status: 200
  Content-Length: 19
  Content-Type: text/plain; charset=utf-8
  Date: $HTTP_DATE$
  lfs: adding d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 to the usercache
  lfs: processed: d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store
  lfs: found d11e1a642b60813aee592094109b406089b8dff4cb157157f753418ec7857998 in the local lfs store
  lfs: found 37a65ab78d5ecda767e8622c248b5dbff1e68b1678ab0e730d5eb8601ec8ad19 in the local lfs store
  lfs: found 31cf46fbc4ecd458a0943c5b4881f1f5a6dd36c53d6167d5b69ac45149b38e5b in the local lfs store

Check error message when the remote missed a blob:

  $ echo FFFFF > b
  $ hg commit -m b -A b
  $ echo FFFFF >> b
  $ hg commit -m b b
  $ rm -rf .hg/store/lfs
  $ rm -rf `hg config lfs.usercache`
  $ hg update -C '.^' --debug
  http auth: user foo, password ***
  resolving manifests
   branchmerge: False, force: True, partial: False
   ancestor: 62fdbaf221c6+, local: 62fdbaf221c6+, remote: ef0564edf47e
  Status: 200
  Content-Length: 308
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "upload": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/8e6ea5f6c066b44a0efa43bcce86aea73f17e6e23f0663df0251e7524e140a13"
          }
        }, 
        "oid": "8e6ea5f6c066b44a0efa43bcce86aea73f17e6e23f0663df0251e7524e140a13", 
        "size": 6
      }
    ]
  }
  abort: LFS server error. Remote object for "b" not found:(.*)! (re)
  [255]

Check error message when object does not exist:

  $ cd $TESTTMP
  $ hg init test && cd test
  $ echo "[extensions]" >> .hg/hgrc
  $ echo "lfs=" >> .hg/hgrc
  $ echo "[lfs]" >> .hg/hgrc
  $ echo "threshold=1" >> .hg/hgrc
  $ echo a > a
  $ hg add a
  $ hg commit -m 'test'
  $ echo aaaaa > a
  $ hg commit -m 'largefile'
  $ hg debugdata .hg/store/data/a.i 1 # verify this is no the file content but includes "oid", the LFS "pointer".
  version https://git-lfs.github.com/spec/v1
  oid sha256:bdc26931acfb734b142a8d675f205becf27560dc461f501822de13274fe6fc8a
  size 6
  x-is-binary 0
  $ cd ..
  $ rm -rf `hg config lfs.usercache`

(Restart the server in a different location so it no longer has the content)

  $ $PYTHON $RUNTESTDIR/killdaemons.py $DAEMON_PIDS
  $ rm $DAEMON_PIDS
  $ mkdir $TESTTMP/lfs-server2
  $ cd $TESTTMP/lfs-server2
#if no-windows
  $ lfs-test-server &> lfs-server.log &
  $ echo $! >> $DAEMON_PIDS
#else
  $ $PYTHON $TESTTMP/spawn.py >> $DAEMON_PIDS
#endif

  $ cd $TESTTMP
  $ hg --debug clone test test2
  http auth: user foo, password ***
  linked 6 files
  http auth: user foo, password ***
  updating to branch default
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 000000000000, local: 000000000000+, remote: d2a338f184a8
  Status: 200
  Content-Length: 308
  Content-Type: application/vnd.git-lfs+json
  Date: $HTTP_DATE$
  {
    "objects": [
      {
        "actions": {
          "upload": {
            "expires_at": "$ISO_8601_DATE_TIME$", 
            "header": {
              "Accept": "application/vnd.git-lfs"
            }, 
            "href": "http://localhost:$HGPORT/objects/bdc26931acfb734b142a8d675f205becf27560dc461f501822de13274fe6fc8a"
          }
        }, 
        "oid": "bdc26931acfb734b142a8d675f205becf27560dc461f501822de13274fe6fc8a", 
        "size": 6
      }
    ]
  }
  abort: LFS server error. Remote object for "a" not found:(.*)! (re)
  [255]

  $ $PYTHON $RUNTESTDIR/killdaemons.py $DAEMON_PIDS