tests/test-ssh.t

branchcache: stop writing more branchcache file on disk than needed

Before this change, we were unconditionally writing a branchmap file for the
filter level passed to `update_disk`. This is actually counter productive if no
update were needed for this filter level. In many case, the branch cache for a
filter level is identical to its parent "subset" and it is better to simply
keep the subset update and reuse it every time instead of having to do identical
work for similar subset.

So we change the `update_disk` method to only write a file when that filter
level differ from its parent. This removes many cases where identical files were
written, requiring multiple boring update in the test suite.

The only notable changes is the change to `test-strip-branch-cache.t`, this
case was checking a scenario that no longer reproduce the bug as writing less
branchmap file result in less stalled cache on disk.

Strictly speaking, we could create a more convoluted scenario that create a
similar issue. However the next changeset would also cover that scenario so we
directly updated that test case to a "no longer buggy" state.

This test tries to exercise the ssh functionality with a dummy script

creating 'remote' repo

  $ hg init remote
  $ cd remote
  $ echo this > foo
  $ echo this > fooO
  $ hg ci -A -m "init" foo fooO

insert a closed branch (issue4428)

  $ hg up null
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg branch closed
  marked working directory as branch closed
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -mc0
  $ hg ci --close-branch -mc1
  $ hg up -q default

configure for serving

  $ cat <<EOF > .hg/hgrc
  > [server]
  > uncompressed = True
  > 
  > [hooks]
  > changegroup = sh -c "printenv.py --line changegroup-in-remote 0 ../dummylog"
  > EOF
  $ cd $TESTTMP

repo not found error

  $ hg clone ssh://user@dummy/nonexistent local
  remote: abort: repository nonexistent not found
  abort: no suitable response from remote hg
  [255]
  $ hg clone -q ssh://user@dummy/nonexistent local
  remote: abort: repository nonexistent not found
  abort: no suitable response from remote hg
  [255]

non-existent absolute path

  $ hg clone ssh://user@dummy/`pwd`/nonexistent local
  remote: abort: repository $TESTTMP/nonexistent not found
  abort: no suitable response from remote hg
  [255]

clone remote via stream

#if no-reposimplestore

  $ hg clone --stream ssh://user@dummy/remote local-stream
  streaming all changes
  9 files to transfer, 827 bytes of data (no-zstd !)
  transferred 827 bytes in * seconds (*) (glob) (no-zstd !)
  9 files to transfer, 846 bytes of data (zstd no-rust !)
  11 files to transfer, 972 bytes of data (zstd rust !)
  transferred * bytes in * seconds (* */sec) (glob) (zstd !)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local-stream
  $ hg verify -q
  $ hg branches
  default                        0:1160648e36ce
  $ cd $TESTTMP

clone bookmarks via stream

  $ hg -R local-stream book mybook
  $ hg clone --stream ssh://user@dummy/local-stream stream2
  streaming all changes
  12 files to transfer, * of data (glob) (no-rust !)
  14 files to transfer, * of data (glob) (rust !)
  transferred * in * seconds (*) (glob)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd stream2
  $ hg book
     mybook                    0:1160648e36ce
  $ cd $TESTTMP
  $ rm -rf local-stream stream2

#endif

clone remote via pull

  $ hg clone ssh://user@dummy/remote local
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files
  new changesets 1160648e36ce:ad076bfb429d
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

verify

  $ cd local
  $ hg verify -q
  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > changegroup = sh -c "printenv.py changegroup-in-local 0 ../dummylog"
  > EOF

empty default pull

  $ hg paths
  default = ssh://user@dummy/remote
  $ hg pull
  pulling from ssh://user@dummy/remote
  searching for changes
  no changes found

pull from wrong ssh URL

  $ hg pull ssh://user@dummy/doesnotexist
  pulling from ssh://user@dummy/doesnotexist
  remote: abort: repository doesnotexist not found
  abort: no suitable response from remote hg
  [255]

local change

  $ echo bleah > foo
  $ hg ci -m "add"

updating rc

  $ echo "default-push = ssh://user@dummy/remote" >> .hg/hgrc

find outgoing

  $ hg out ssh://user@dummy/remote
  comparing with ssh://user@dummy/remote
  searching for changes
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  

find incoming on the remote side

  $ hg incoming -R ../remote ssh://user@dummy/local
  comparing with ssh://user@dummy/local
  searching for changes
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  

find incoming on the remote side (using absolute path)

  $ hg incoming -R ../remote "ssh://user@dummy/`pwd`"
  comparing with ssh://user@dummy/$TESTTMP/local
  searching for changes
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  

push

  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  $ cd $TESTTMP/remote

check remote tip

  $ hg tip
  changeset:   3:a28a9d1a809c
  tag:         tip
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add
  
  $ hg verify -q
  $ hg cat -r tip foo
  bleah
  $ echo z > z
  $ hg ci -A -m z z
  created new head

test pushkeys and bookmarks

  $ cd $TESTTMP/local
  $ hg debugpushkey ssh://user@dummy/remote namespaces
  bookmarks	
  namespaces	
  phases	
  $ hg book foo -r 0
  $ hg out -B --config paths.default=bogus://invalid --config paths.default:pushurl=`hg paths default`
  comparing with ssh://user@dummy/remote
  searching for changed bookmarks
     foo                       1160648e36ce
  $ hg push -B foo
  pushing to ssh://user@dummy/remote
  searching for changes
  no changes found
  exporting bookmark foo
  [1]
  $ hg debugpushkey ssh://user@dummy/remote bookmarks
  foo	1160648e36cec0054048a7edc4110c6f84fde594
  $ hg book -f foo
  $ hg push --traceback
  pushing to ssh://user@dummy/remote
  searching for changes
  no changes found
  updating bookmark foo
  [1]
  $ hg book -d foo
  $ hg in -B
  comparing with ssh://user@dummy/remote
  searching for changed bookmarks
     foo                       a28a9d1a809c
  $ hg book -f -r 0 foo
  $ hg pull -B foo
  pulling from ssh://user@dummy/remote
  no changes found
  updating bookmark foo
  $ hg book -d foo
  $ hg push -B foo
  pushing to ssh://user@dummy/remote
  searching for changes
  no changes found
  deleting remote bookmark foo
  [1]

a bad, evil hook that prints to stdout

  $ cat <<EOF > $TESTTMP/badhook
  > import sys
  > sys.stdout.write("KABOOM\n")
  > sys.stdout.flush()
  > EOF

  $ cat <<EOF > $TESTTMP/badpyhook.py
  > import sys
  > def hook(ui, repo, hooktype, **kwargs):
  >     sys.stdout.write("KABOOM IN PROCESS\n")
  >     sys.stdout.flush()
  > EOF

  $ cat <<EOF >> ../remote/.hg/hgrc
  > [hooks]
  > changegroup.stdout = "$PYTHON" $TESTTMP/badhook
  > changegroup.pystdout = python:$TESTTMP/badpyhook.py:hook
  > EOF
  $ echo r > r
  $ hg ci -A -m z r

push should succeed even though it has an unexpected response

  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote has heads on branch 'default' that are not known locally: 6c0482d977a3
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: KABOOM
  remote: KABOOM IN PROCESS
  $ hg -R ../remote heads
  changeset:   5:1383141674ec
  tag:         tip
  parent:      3:a28a9d1a809c
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     z
  
  changeset:   4:6c0482d977a3
  parent:      0:1160648e36ce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     z
  

#if chg

try again with remote chg, which should succeed as well

  $ hg rollback -R ../remote
  repository tip rolled back to revision 4 (undo serve)

  $ hg push --config ui.remotecmd=chg
  pushing to ssh://user@dummy/remote
  searching for changes
  remote has heads on branch 'default' that are not known locally: 6c0482d977a3
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: KABOOM
  remote: KABOOM IN PROCESS

#endif

clone bookmarks

  $ hg -R ../remote bookmark test
  $ hg -R ../remote bookmarks
   * test                      4:6c0482d977a3
  $ hg clone ssh://user@dummy/remote local-bookmarks
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 5 changes to 4 files (+1 heads)
  new changesets 1160648e36ce:1383141674ec
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R local-bookmarks bookmarks
     test                      4:6c0482d977a3

passwords in ssh urls are not supported
(we use a glob here because different Python versions give different
results here)

  $ hg push ssh://user:erroneouspwd@dummy/remote
  pushing to ssh://user:*@dummy/remote (glob)
  abort: password in URL not supported
  [255]

  $ cd $TESTTMP

hide outer repo
  $ hg init

Test remote paths with spaces (issue2983):

  $ hg init "ssh://user@dummy/a repo"
  $ touch "$TESTTMP/a repo/test"
  $ hg -R 'a repo' commit -A -m "test"
  adding test
  $ hg -R 'a repo' tag tag
  $ hg id "ssh://user@dummy/a repo"
  73649e48688a

  $ hg id "ssh://user@dummy/a repo#noNoNO"
  abort: unknown revision 'noNoNO'
  [255]

Test (non-)escaping of remote paths with spaces when cloning (issue3145):

  $ hg clone "ssh://user@dummy/a repo"
  destination directory: a repo
  abort: destination 'a repo' is not empty
  [10]

#if no-rhg
Make sure hg is really paranoid in serve --stdio mode. It used to be
possible to get a debugger REPL by specifying a repo named --debugger.
  $ hg -R --debugger serve --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', '--debugger', 'serve', '--stdio']
  [255]
  $ hg -R --config=ui.debugger=yes serve --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', '--config=ui.debugger=yes', 'serve', '--stdio']
  [255]
Abbreviations of 'serve' also don't work, to avoid shenanigans.
  $ hg -R narf serv --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', 'narf', 'serv', '--stdio']
  [255]
#else
rhg aborts early on -R without a repository at that path
  $ hg -R --debugger serve --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', '--debugger', 'serve', '--stdio'] (missing-correct-output !)
  abort: repository --debugger not found (known-bad-output !)
  [255]
  $ hg -R --config=ui.debugger=yes serve --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', '--config=ui.debugger=yes', 'serve', '--stdio'] (missing-correct-output !)
  abort: repository --config=ui.debugger=yes not found (known-bad-output !)
  [255]
  $ hg -R narf serv --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', 'narf', 'serv', '--stdio'] (missing-correct-output !)
  abort: repository narf not found (known-bad-output !)
  [255]
If the repo does exist, rhg finds an unsupported command and falls back to Python
which still does the right thing
  $ hg init narf
  $ hg -R narf serv --stdio
  abort: potentially unsafe serve --stdio invocation: ['-R', 'narf', 'serv', '--stdio']
  [255]
#endif

Test hg-ssh using a helper script that will restore PYTHONPATH (which might
have been cleared by a hg.exe wrapper) and invoke hg-ssh with the right
parameters:

  $ cat > ssh.sh << EOF
  > userhost="\$1"
  > SSH_ORIGINAL_COMMAND="\$2"
  > export SSH_ORIGINAL_COMMAND
  > PYTHONPATH="$PYTHONPATH"
  > export PYTHONPATH
  > "$PYTHON" "$TESTDIR/../contrib/hg-ssh" "$TESTTMP/a repo"
  > EOF

  $ hg id --ssh "sh ssh.sh" "ssh://user@dummy/a repo"
  73649e48688a

  $ hg id --ssh "sh ssh.sh" "ssh://user@dummy/a'repo"
  remote: Illegal repository "$TESTTMP/a'repo"
  abort: no suitable response from remote hg
  [255]

  $ hg id --ssh "sh ssh.sh" --remotecmd hacking "ssh://user@dummy/a'repo"
  remote: Illegal command "hacking -R 'a'\''repo' serve --stdio"
  abort: no suitable response from remote hg
  [255]

  $ SSH_ORIGINAL_COMMAND="'hg' -R 'a'repo' serve --stdio" "$PYTHON" "$TESTDIR/../contrib/hg-ssh"
  Illegal command "'hg' -R 'a'repo' serve --stdio": No closing quotation
  [255]

Test hg-ssh in read-only mode:

  $ cat > ssh.sh << EOF
  > userhost="\$1"
  > SSH_ORIGINAL_COMMAND="\$2"
  > export SSH_ORIGINAL_COMMAND
  > PYTHONPATH="$PYTHONPATH"
  > export PYTHONPATH
  > "$PYTHON" "$TESTDIR/../contrib/hg-ssh" --read-only "$TESTTMP/remote"
  > EOF

  $ hg clone --ssh "sh ssh.sh" "ssh://user@dummy/$TESTTMP/remote" read-only-local
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 5 changes to 4 files (+1 heads)
  new changesets 1160648e36ce:1383141674ec
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd read-only-local
  $ echo "baz" > bar
  $ hg ci -A -m "unpushable commit" bar
  $ hg push --ssh "sh ../ssh.sh"
  pushing to ssh://user@dummy/*/remote (glob)
  searching for changes
  remote: $EACCES$
  remote: pretxnopen.hg-ssh hook failed
  abort: push failed on remote
  [100]

  $ cd $TESTTMP

stderr from remote commands should be printed before stdout from local code (issue4336)

  $ hg clone remote stderr-ordering
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd stderr-ordering
  $ cat >> localwrite.py << EOF
  > from mercurial import exchange, extensions
  > 
  > def wrappedpush(orig, repo, *args, **kwargs):
  >     res = orig(repo, *args, **kwargs)
  >     repo.ui.write(b'local stdout\n')
  >     repo.ui.flush()
  >     return res
  > 
  > def extsetup(ui):
  >     extensions.wrapfunction(exchange, 'push', wrappedpush)
  > EOF

  $ cat >> .hg/hgrc << EOF
  > [paths]
  > default-push = ssh://user@dummy/remote
  > [extensions]
  > localwrite = localwrite.py
  > EOF

  $ echo localwrite > foo
  $ hg commit -m 'testing localwrite'
  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: KABOOM
  remote: KABOOM IN PROCESS
  local stdout

debug output

  $ hg pull --debug ssh://user@dummy/remote --config devel.debug.peer-request=yes
  pulling from ssh://user@dummy/remote
  running .* ".*[/\\]dummyssh" ['"]user@dummy['"] ['"]hg -R remote serve --stdio['"] (re)
  devel-peer-request: hello+between
  devel-peer-request:   pairs: 81 bytes
  sending hello command
  sending between command
  remote: \d+ (re)
  remote: capabilities: batch branchmap \$USUAL_BUNDLE2_CAPS\$ changegroupsubset getbundle known lookup protocaps pushkey streamreqs=[^ ,]+(,[^ ,]+)* unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash (re)
  remote: 1
  devel-peer-request: protocaps
  devel-peer-request:   caps: * bytes (glob)
  sending protocaps command
  query 1; heads
  devel-peer-request: batched-content
  devel-peer-request:    - heads (0 arguments)
  devel-peer-request:    - known (1 arguments)
  devel-peer-request: batch
  devel-peer-request:   cmds: 141 bytes
  sending batch command
  searching for changes
  all remote heads known locally
  no changes found
  devel-peer-request: getbundle
  devel-peer-request:   bookmarks: 1 bytes
  devel-peer-request:   bundlecaps: 275 bytes
  devel-peer-request:   cg: 1 bytes
  devel-peer-request:   common: 122 bytes
  devel-peer-request:   heads: 122 bytes
  devel-peer-request:   listkeys: 9 bytes
  devel-peer-request:   phases: 1 bytes
  sending getbundle command
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "bookmarks" supported
  bundle2-input-part: total payload size 26
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-part: total payload size 45
  bundle2-input-part: "phase-heads" supported
  bundle2-input-part: total payload size 72
  bundle2-input-bundle: 3 parts total
  checking for updated bookmarks

  $ cd $TESTTMP

  $ cat dummylog
  Got arguments 1:user@dummy 2:hg -R nonexistent serve --stdio
  Got arguments 1:user@dummy 2:hg -R nonexistent serve --stdio
  Got arguments 1:user@dummy 2:hg -R $TESTTMP/nonexistent serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R local-stream serve --stdio (no-reposimplestore !)
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio (no-reposimplestore !)
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio (no-reposimplestore !)
  Got arguments 1:user@dummy 2:hg -R doesnotexist serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R local serve --stdio
  Got arguments 1:user@dummy 2:hg -R $TESTTMP/local serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  changegroup-in-remote hook: HG_BUNDLE2=1
  HG_HOOKNAME=changegroup
  HG_HOOKTYPE=changegroup
  HG_NODE=a28a9d1a809cab7d4e2fde4bee738a9ede948b60
  HG_NODE_LAST=a28a9d1a809cab7d4e2fde4bee738a9ede948b60
  HG_SOURCE=serve
  HG_TXNID=TXN:$ID$
  HG_TXNNAME=serve
  HG_URL=remote:ssh:$LOCALIP
  
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  changegroup-in-remote hook: HG_BUNDLE2=1
  HG_HOOKNAME=changegroup
  HG_HOOKTYPE=changegroup
  HG_NODE=1383141674ec756a6056f6a9097618482fe0f4a6
  HG_NODE_LAST=1383141674ec756a6056f6a9097618482fe0f4a6
  HG_SOURCE=serve
  HG_TXNID=TXN:$ID$
  HG_TXNNAME=serve
  HG_URL=remote:ssh:$LOCALIP
  
  Got arguments 1:user@dummy 2:chg -R remote serve --stdio (chg !)
  changegroup-in-remote hook: HG_BUNDLE2=1 (chg !)
  HG_HOOKNAME=changegroup (chg !)
  HG_HOOKTYPE=changegroup (chg !)
  HG_NODE=1383141674ec756a6056f6a9097618482fe0f4a6 (chg !)
  HG_NODE_LAST=1383141674ec756a6056f6a9097618482fe0f4a6 (chg !)
  HG_SOURCE=serve (chg !)
  HG_TXNID=TXN:$ID$ (chg !)
  HG_TXNNAME=serve (chg !)
  HG_URL=remote:ssh:$LOCALIP (chg !)
   (chg !)
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  Got arguments 1:user@dummy 2:hg init 'a repo'
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R 'a repo' serve --stdio
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio
  changegroup-in-remote hook: HG_BUNDLE2=1
  HG_HOOKNAME=changegroup
  HG_HOOKTYPE=changegroup
  HG_NODE=65c38f4125f9602c8db4af56530cc221d93b8ef8
  HG_NODE_LAST=65c38f4125f9602c8db4af56530cc221d93b8ef8
  HG_SOURCE=serve
  HG_TXNID=TXN:$ID$
  HG_TXNNAME=serve
  HG_URL=remote:ssh:$LOCALIP
  
  Got arguments 1:user@dummy 2:hg -R remote serve --stdio


remote hook failure is attributed to remote

  $ cat > $TESTTMP/failhook << EOF
  > def hook(ui, repo, **kwargs):
  >     ui.write(b'hook failure!\n')
  >     ui.flush()
  >     return 1
  > EOF

  $ echo "pretxnchangegroup.fail = python:$TESTTMP/failhook:hook" >> remote/.hg/hgrc

  $ hg -q clone ssh://user@dummy/remote hookout
  $ cd hookout
  $ touch hookfailure
  $ hg -q commit -A -m 'remote hook failure'
  $ hg push
  pushing to ssh://user@dummy/remote
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: hook failure!
  remote: transaction abort!
  remote: rollback completed
  remote: pretxnchangegroup.fail hook failed
  abort: push failed on remote
  [100]

abort during pull is properly reported as such

  $ echo morefoo >> ../remote/foo
  $ hg -R ../remote commit --message "more foo to be pulled"
  $ cat >> ../remote/.hg/hgrc << EOF
  > [extensions]
  > crash = ${TESTDIR}/crashgetbundler.py
  > EOF
  $ hg pull
  pulling from ssh://user@dummy/remote
  searching for changes
  remote: abort: this is an exercise
  abort: pull failed on remote
  [100]

abort with no error hint when there is a ssh problem when pulling

  $ hg pull ssh://brokenrepository
  pulling from ssh://brokenrepository/
  abort: no suitable response from remote hg
  [255]

abort with configured error hint when there is a ssh problem when pulling

  $ hg pull ssh://brokenrepository \
  > --config ui.ssherrorhint="Please see http://company/internalwiki/ssh.html"
  pulling from ssh://brokenrepository/
  abort: no suitable response from remote hg
  (Please see http://company/internalwiki/ssh.html)
  [255]

test that custom environment is passed down to ssh executable
  $ cat >>dumpenv <<EOF
  > #! /bin/sh
  > echo \$VAR >&2
  > EOF
  $ chmod +x dumpenv
  $ hg pull ssh://something --config ui.ssh="sh dumpenv"
  pulling from ssh://something/
  remote: 
  abort: no suitable response from remote hg
  [255]
  $ hg pull ssh://something --config ui.ssh="sh dumpenv" --config sshenv.VAR=17
  pulling from ssh://something/
  remote: 17
  abort: no suitable response from remote hg
  [255]