view tests/test-patch.t @ 36426:23d12524a202

http: drop custom http client logic

Eight and a half years ago, as my starter bug on code.google.com, I
investigated a mysterious "broken pipe" error from seemingly random
clients[0]. That investigation revealed a tragic story: the Python
standard library's httplib was (and remains) barely functional. During
large POSTs, if a server responds early with an error (even a
permission denied error!) the client only notices that the server
closed the connection and everything breaks. Such server behavior is
implicitly legal under RFC 2616 (the latest HTTP RFC as of when I was
last working on this), and my understanding is that later RFCs have
made it explicitly legal to respond early with any status code outside
the 2xx range.

I embarked, probably foolishly, on a journey to write a new http
library with better overall behavior. The http library appears to work
well in most cases, but it can get confused in the presence of
proxies, and it depends on select(2) which limits its utility if a lot
of file descriptors are open. I haven't touched the http library in
almost two years, and in the interim the Python community has
discovered a better way[1] of writing network code. In theory some day
urllib3 will have its own home-grown http library built on h11[2], or
we could do that. Either way, it's time to declare our current
confusingly-named "http2" client logic and move on. I do hope to
revisit this some day: it's still garbage that we can't even respond
with a 401 or 403 without reading the entire POST body from the
client, but the goalposts on writing a new http client library have
moved substantially. We're almost certainly better off just switching
to requests and eventually picking up their http fixes than trying to
live with something that realistically only we'll ever use. Another
approach would be to write an adapter so that Mercurial can use pycurl
if it's installed. Neither of those approaches seem like they should
be investigated prior to a release of Mercurial that works on Python
3: that's where the mindshare is going to be for any improvements to
the state of the http client art.

0: http://web.archive.org/web/20130501031801/http://code.google.com/p/support/issues/detail?id=2716
1: http://sans-io.readthedocs.io/
2: https://github.com/njsmith/h11

Differential Revision: https://phab.mercurial-scm.org/D2444

  $ cat > patchtool.py <<EOF
  > from __future__ import absolute_import, print_function
  > import sys
  > print('Using custom patch')
  > if '--binary' in sys.argv:
  >     print('--binary found !')
  > EOF

  $ echo "[ui]" >> $HGRCPATH
  $ echo "patch=$PYTHON ../patchtool.py" >> $HGRCPATH

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg commit -Ama -d '1 0'
  adding a
  $ echo b >> a
  $ hg commit -Amb -d '2 0'
  $ cd ..

This test checks that:
 - custom patch commands with arguments actually work
 - patch code does not try to add weird arguments like
 --binary when custom patch commands are used. For instance
 --binary is added by default under win32.

check custom patch options are honored

  $ hg --cwd a export -o ../a.diff tip
  $ hg clone -r 0 a b
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 8580ff50825a
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg --cwd b import -v ../a.diff
  applying ../a.diff
  Using custom patch
  applied to working directory

Issue2417: hg import with # comments in description

Prepare source repo and patch:

  $ rm $HGRCPATH
  $ hg init c
  $ cd c
  $ printf "a\rc" > a
  $ hg ci -A -m 0 a -d '0 0'
  $ printf "a\rb\rc" > a
  $ cat << eof > log
  > first line which can't start with '# '
  > # second line is a comment but that shouldn't be a problem.
  > A patch marker like this was more problematic even after d7452292f9d3:
  > # HG changeset patch
  > # User lines looks like this - but it _is_ just a comment
  > eof
  $ hg ci -l log -d '0 0'
  $ hg export -o p 1
  $ cd ..

Clone and apply patch:

  $ hg clone -r 0 c d
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 7fadb901d403
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd d
  $ hg import ../c/p
  applying ../c/p
  $ hg log -v -r 1
  changeset:   1:cd0bde79c428
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       a
  description:
  first line which can't start with '# '
  # second line is a comment but that shouldn't be a problem.
  A patch marker like this was more problematic even after d7452292f9d3:
  # HG changeset patch
  # User lines looks like this - but it _is_ just a comment
  
  
  $ cd ..