test: add test-transaction-rollback-on-sigpipe.t demonstrating py3 regression
When an hg push is interrupted with C-c, the remote [hg serve] command
receives SIGPIPE.
If a pretxnchangegroup hook fails, the remote hg then tries to
rollback the transaction. It begins by printing "transaction
abort!\n". This returns EPIPE, but ui.py ignores that error.
In python3 (but not python2), this "transaction abort!\n" message
stays in a buffer, so future flushes of stderr will try to print the
message again, and so those flushes will also hit EPIPE.
This test demonstrates such a case where this EPIPE causes the
transaction rollback to fail, leaving behind an abandoned transaction.
Differential Revision: https://phab.mercurial-scm.org/D9151
$ cat > writepatterns.py <<EOF
> import sys
>
> path = sys.argv[1]
> patterns = sys.argv[2:]
>
> fp = open(path, 'wb')
> for pattern in patterns:
> count = int(pattern[0:-1])
> char = pattern[-1].encode('utf8') + b'\n'
> fp.write(char * count)
> fp.close()
> EOF
prepare repo
$ hg init a
$ cd a
These initial lines of Xs were not in the original file used to generate
the patch. So all the patch hunks need to be applied to a constant offset
within this file. If the offset isn't tracked then the hunks can be
applied to the wrong lines of this file.
$ "$PYTHON" ../writepatterns.py a 34X 10A 1B 10A 1C 10A 1B 10A 1D 10A 1B 10A 1E 10A 1B 10A
$ hg commit -Am adda
adding a
This is a cleaner patch generated via diff
In this case it reproduces the problem when
the output of hg export does not
import patch
$ hg import -v -m 'b' -d '2 0' - <<EOF
> --- a/a 2009-12-08 19:26:17.000000000 -0800
> +++ b/a 2009-12-08 19:26:17.000000000 -0800
> @@ -9,7 +9,7 @@
> A
> A
> B
> -A
> +a
> A
> A
> A
> @@ -53,7 +53,7 @@
> A
> A
> B
> -A
> +a
> A
> A
> A
> @@ -75,7 +75,7 @@
> A
> A
> B
> -A
> +a
> A
> A
> A
> EOF
applying patch from stdin
patching file a
Hunk #1 succeeded at 43 (offset 34 lines).
Hunk #2 succeeded at 87 (offset 34 lines).
Hunk #3 succeeded at 109 (offset 34 lines).
committing files:
a
committing manifest
committing changelog
created 189885cecb41
compare imported changes against reference file
$ "$PYTHON" ../writepatterns.py aref 34X 10A 1B 1a 9A 1C 10A 1B 10A 1D 10A 1B 1a 9A 1E 10A 1B 1a 9A
$ diff aref a
$ cd ..