New test pushcrash.t.

This tests how git push to a remote hg repository reacts when hg
crashes.  Currently: by having git-cinnabar crash too.

glandium#338

tests/pushcrash.t

@@ -0,0 +1,92 @@
+#!/usr/bin/env cram
+
+  $ PATH=$TESTDIR/..:$PATH
+
+Test repository setup.
+
+  $ n=0
+  $ createhg() {
+  >   echo $1 > $1
+  >   hg add $1
+  >   hg commit -q -m $1 -u nobody -d "$n 0"
+  >   n=$(expr $n + 1)
+  > }
+  $ creategit() {
+  >   echo $1 > $1
+  >   git add $1
+  >   GIT_COMMITTER_DATE="1970-01-01 0:0:$n" git -c user.name=Nobody -c user.email=nobody@nowhere commit -q -m $1 --date "1970-01-01 0:0:$n"
+  >   n=$(expr $n + 1)
+  > }
+
+Create an hg repository with an initial commit:
+
+  $ hg init repo.hg
+  $ cd repo.hg
+  $ createhg x
+  $ cd ..
+  $ hg -R repo.hg log -G
+  @  changeset:   0:2642976da98a
+     tag:         tip
+     user:        nobody
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     x
+
+
+Clone it with git-cinnabar:
+
+  $ git -c fetch.prune=true clone -n -q hg::$(pwd)/repo.hg repo.git
+  $ git -C repo.git log --graph --decorate=short branches/default/tip
+  * commit d51ea055a776dc74cc3d013441af88d26b68ab88 (HEAD -> branches/default/tip, origin/branches/default/tip, origin/HEAD)
+    Author: nobody <>
+    Date:   Thu Jan 1 00:00:00 1970 +0000
+
+        x
+
+Configure the hg repository with a broken hook so it crashes:
+
+  $ cat <<EOF >repo.hg/.hg/hgrc
+  > [hooks]
+  > pretxnclose = python:/nonexistent:fail
+  > EOF
+
+Commit something in the git clone:
+
+  $ cd repo.git
+  $ creategit z
+  $ cd ..
+
+XXX git-cinnabar failure is a bit ungraceful!
+git push fails gracefully with nonzero exit status:
+
+  $ git -C repo.git push origin
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: loading pretxnclose hook failed:
+  remote: transaction abort!
+  remote: rollback completed
+  remote: abort: No such file or directory: '/nonexistent'
+  fatal: called `Result::unwrap()` on an `Err` value: Error { kind: UnexpectedEof, message: "failed to fill whole buffer" }
+  Run the command again with `git -c cinnabar.check=traceback <command>` to see the full traceback.
+  error: git-remote-hg died of signal 6
+  error: failed to push some refs to 'hg::*/cramtests-*/pushcrash.t/repo.hg' (glob)
+  [1]
+
+The change does not appear in the hg repository:
+
+  $ hg -R repo.hg log -G
+  @  changeset:   0:2642976da98a
+     tag:         tip
+     user:        nobody
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     x
+
+
+The git-cinnabar remote does not reflect the failed push:
+
+  $ git -C repo.git log --graph --decorate=short origin/branches/default/tip
+  * commit d51ea055a776dc74cc3d013441af88d26b68ab88 (origin/branches/default/tip, origin/HEAD)
+    Author: nobody <>
+    Date:   Thu Jan 1 00:00:00 1970 +0000
+
+        x