view contrib/mercurial.spec @ 35884:197d10e157ce

httppeer: remove support for connecting to <0.9.1 servers (BC)

Previously, HTTP wire protocol clients would attempt a
"capabilities" wire protocol command. If that failed, they would
fall back to issuing a "between" command.

The "capabilities" command was added in Mercurial 0.9.1 (released
July 2006). The "between" command has been present for as long as
the wire protocol has existed. So if the "between" command failed,
it was safe to assume that the remote could not speak any version
of the Mercurial wire protocol.

The "between" fallback was added in 395a84f78736 in 2011. Before that
changeset, Mercurial would *always* issue the "between" command and
would issue "capabilities" if capabilities were requested. At that time,
many connections would issue "capabilities" eventually, so it was
decided to issue "capabilities" by default and fall back to "between"
if that failed. This saved a round trip when connecting to modern
servers while still preserving compatibility with legacy servers.

Fast forward ~7 years. Mercurial servers supporting "capabilities"
have been around for over a decade. If modern clients are
connecting to <0.9.1 servers, they are getting a bad experience.
They may even be getting bad data (an old server is vulnerable to
numerous security issues and could have been p0wned, leading to a
Mercurial repository serving backdoors or other badness).

In addition, the fallback can harm experience for modern servers.
If a client experiences an intermittent HTTP request failure (due to
bad network, etc) and falls back to a "between" that works, it would
assume an empty capability set and would attempt to communicate with
the repository using a very ancient wire protocol. Auditing HTTP logs
for hg.mozilla.org, I did find a handful of requests for the
null range of the "between" command. However, requests can be days
apart. And when I do see requests, they come in batches. Those
batches seem to correlate to spikes of HTTP 500 or other
server/network events. So I think these requests are fallbacks from
failed "capabilities" requests and not from old clients.

If you need even more evidence to discontinue support, apparently
we have no test coverage for communicating with servers not
supporting "capabilities." I know this because all tests pass
with the "between" fallback removed.

Finally, server-side support for <0.9.1 pushing (the "addchangegroup"
wire protocol command along with locking-related commands) was dropped
from the HTTP client in fda0867cfe03 in 2017 and the SSH client in
9f6e0e7ef828 in 2015.

I think this all adds up to enough justification for removing client
support for communicating with servers not supporting "capabilities."
So this commit removes that fallback.

Differential Revision: https://phab.mercurial-scm.org/D2001

%global emacs_lispdir %{_datadir}/emacs/site-lisp

%define withpython %{nil}

%if "%{?withpython}"

%global pythonver %{withpython}
%global pythonname Python-%{withpython}
%global docutilsname docutils-0.12
%global docutilsmd5 4622263b62c5c771c03502afa3157768
%global pythonhg python-hg
%global hgpyprefix /opt/%{pythonhg}
# byte compilation will fail on some some Python /test/ files
%global _python_bytecompile_errors_terminate_build 0

%else

%global pythonver %(python -c 'import sys;print ".".join(map(str, sys.version_info[:2]))')

%endif

Summary: A fast, lightweight Source Control Management system
Name: mercurial
Version: snapshot
Release: 0
License: GPLv2+
Group: Development/Tools
URL: https://mercurial-scm.org/
Source0: %{name}-%{version}-%{release}.tar.gz
%if "%{?withpython}"
Source1: %{pythonname}.tgz
Source2: %{docutilsname}.tar.gz
%endif
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root

BuildRequires: make, gcc, gettext
%if "%{?withpython}"
BuildRequires: readline-devel, openssl-devel, ncurses-devel, zlib-devel, bzip2-devel
%else
BuildRequires: python >= 2.7, python-devel, python-docutils >= 0.5
Requires: python >= 2.7
%endif
# The hgk extension uses the wish tcl interpreter, but we don't enforce it
#Requires: tk

%description
Mercurial is a fast, lightweight source control management system designed
for efficient handling of very large distributed projects.

%prep

%if "%{?withpython}"
%setup -q -n mercurial-%{version}-%{release} -a1 -a2
# despite the comments in cgi.py, we do this to prevent rpmdeps from picking /usr/local/bin/python up
sed -i '1c#! /usr/bin/env python' %{pythonname}/Lib/cgi.py
%else
%setup -q -n mercurial-%{version}-%{release}
%endif

%build

%if "%{?withpython}"

PYPATH=$PWD/%{pythonname}
cd $PYPATH
./configure --prefix=%{hgpyprefix}
make all %{?_smp_mflags}
cd -

cd %{docutilsname}
LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py build
cd -

# verify Python environment
LD_LIBRARY_PATH=$PYPATH PYTHONPATH=$PWD/%{docutilsname} $PYPATH/python -c 'import sys, zlib, bz2, ssl, curses, readline'

# set environment for make
export PATH=$PYPATH:$PATH
export LD_LIBRARY_PATH=$PYPATH
export CFLAGS="-L $PYPATH"
export PYTHONPATH=$PWD/%{docutilsname}

%endif

make all
make -C contrib/chg

%install
rm -rf $RPM_BUILD_ROOT

%if "%{?withpython}"

PYPATH=$PWD/%{pythonname}
cd $PYPATH
make install DESTDIR=$RPM_BUILD_ROOT
# these .a are not necessary and they are readonly and strip fails - kill them!
rm -f %{buildroot}%{hgpyprefix}/lib/{,python2.*/config}/libpython2.*.a
cd -

cd %{docutilsname}
LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py install --root="$RPM_BUILD_ROOT"
cd -

PATH=$PYPATH:$PATH LD_LIBRARY_PATH=$PYPATH make install DESTDIR=$RPM_BUILD_ROOT PREFIX=%{hgpyprefix} MANDIR=%{_mandir}
mkdir -p $RPM_BUILD_ROOT%{_bindir}
( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/hg . )
( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/python2.? %{pythonhg} )

%else

make install DESTDIR=$RPM_BUILD_ROOT PREFIX=%{_prefix} MANDIR=%{_mandir}

%endif

install -m 755 contrib/chg/chg $RPM_BUILD_ROOT%{_bindir}/
install -m 755 contrib/hgk $RPM_BUILD_ROOT%{_bindir}/
install -m 755 contrib/hg-ssh $RPM_BUILD_ROOT%{_bindir}/

bash_completion_dir=$RPM_BUILD_ROOT%{_sysconfdir}/bash_completion.d
mkdir -p $bash_completion_dir
install -m 644 contrib/bash_completion $bash_completion_dir/mercurial.sh

zsh_completion_dir=$RPM_BUILD_ROOT%{_datadir}/zsh/site-functions
mkdir -p $zsh_completion_dir
install -m 644 contrib/zsh_completion $zsh_completion_dir/_mercurial

mkdir -p $RPM_BUILD_ROOT%{emacs_lispdir}
install -m 644 contrib/mercurial.el $RPM_BUILD_ROOT%{emacs_lispdir}/
install -m 644 contrib/mq.el $RPM_BUILD_ROOT%{emacs_lispdir}/

mkdir -p $RPM_BUILD_ROOT/%{_sysconfdir}/mercurial/hgrc.d

%clean
rm -rf $RPM_BUILD_ROOT

%files
%defattr(-,root,root,-)
%doc CONTRIBUTORS COPYING doc/README doc/hg*.txt doc/hg*.html *.cgi contrib/*.fcgi
%doc %attr(644,root,root) %{_mandir}/man?/hg*
%doc %attr(644,root,root) contrib/*.svg
%dir %{_datadir}/zsh/
%dir %{_datadir}/zsh/site-functions/
%{_datadir}/zsh/site-functions/_mercurial
%dir %{_datadir}/emacs/site-lisp/
%{_datadir}/emacs/site-lisp/mercurial.el
%{_datadir}/emacs/site-lisp/mq.el
%{_bindir}/hg
%{_bindir}/chg
%{_bindir}/hgk
%{_bindir}/hg-ssh
%dir %{_sysconfdir}/bash_completion.d/
%config(noreplace) %{_sysconfdir}/bash_completion.d/mercurial.sh
%dir %{_sysconfdir}/mercurial
%dir %{_sysconfdir}/mercurial/hgrc.d
%if "%{?withpython}"
%{_bindir}/%{pythonhg}
%{hgpyprefix}
%else
%{_libdir}/python%{pythonver}/site-packages/%{name}-*-py%{pythonver}.egg-info
%{_libdir}/python%{pythonver}/site-packages/%{name}
%{_libdir}/python%{pythonver}/site-packages/hgext
%{_libdir}/python%{pythonver}/site-packages/hgext3rd
%{_libdir}/python%{pythonver}/site-packages/hgdemandimport
%endif