view tests/test-rebase-named-branches.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 >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
  > EOF

  $ hg init a
  $ cd a
  $ hg unbundle "$TESTDIR/bundles/rebase.hg"
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd ..

  $ hg clone -q -u . a a1

  $ cd a1

  $ hg update 3
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg branch dev-one
  marked working directory as branch dev-one
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m 'dev-one named branch'

  $ hg update 7
  2 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ hg branch dev-two
  marked working directory as branch dev-two

  $ echo x > x

  $ hg add x

  $ hg ci -m 'dev-two named branch'

  $ hg tglog
  @  9: cb039b7cae8e 'dev-two named branch' dev-two
  |
  | o  8: 643fc9128048 'dev-one named branch' dev-one
  | |
  o |  7: 02de42196ebe 'H'
  | |
  +---o  6: eea13746799a 'G'
  | | |
  o | |  5: 24b6387c8c8c 'F'
  | | |
  +---o  4: 9520eea781bc 'E'
  | |
  | o  3: 32af7686d403 'D'
  | |
  | o  2: 5fddd98957c8 'C'
  | |
  | o  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  

Branch name containing a dash (issue3181)

  $ hg rebase -b dev-two -d dev-one --keepbranches
  rebasing 5:24b6387c8c8c "F"
  rebasing 6:eea13746799a "G"
  rebasing 7:02de42196ebe "H"
  rebasing 9:cb039b7cae8e "dev-two named branch" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/24b6387c8c8c-24cb8001-rebase.hg

  $ hg tglog
  @  9: 9e70cd31750f 'dev-two named branch' dev-two
  |
  o  8: 31d0e4ba75e6 'H'
  |
  | o  7: 4b988a958030 'G'
  |/|
  o |  6: 24de4aff8e28 'F'
  | |
  o |  5: 643fc9128048 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  | |
  o |  3: 32af7686d403 'D'
  | |
  o |  2: 5fddd98957c8 'C'
  | |
  o |  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg rebase -s dev-one -d 0 --keepbranches
  rebasing 5:643fc9128048 "dev-one named branch"
  rebasing 6:24de4aff8e28 "F"
  rebasing 7:4b988a958030 "G"
  rebasing 8:31d0e4ba75e6 "H"
  rebasing 9:9e70cd31750f "dev-two named branch" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/643fc9128048-c4ee9ef5-rebase.hg

  $ hg tglog
  @  9: 59c2e59309fe 'dev-two named branch' dev-two
  |
  o  8: 904590360559 'H'
  |
  | o  7: 1a1e6f72ec38 'G'
  |/|
  o |  6: 42aa3cf0fa7a 'F'
  | |
  o |  5: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  |/
  | o  3: 32af7686d403 'D'
  | |
  | o  2: 5fddd98957c8 'C'
  | |
  | o  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg update 3
  3 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ hg branch -f dev-one
  marked working directory as branch dev-one
  $ hg ci -m 'dev-one named branch'
  created new head

  $ hg tglog
  @  10: 643fc9128048 'dev-one named branch' dev-one
  |
  | o  9: 59c2e59309fe 'dev-two named branch' dev-two
  | |
  | o  8: 904590360559 'H'
  | |
  | | o  7: 1a1e6f72ec38 'G'
  | |/|
  | o |  6: 42aa3cf0fa7a 'F'
  | | |
  | o |  5: bc8139ee757c 'dev-one named branch' dev-one
  | | |
  | | o  4: 9520eea781bc 'E'
  | |/
  o |  3: 32af7686d403 'D'
  | |
  o |  2: 5fddd98957c8 'C'
  | |
  o |  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg rebase -b 'max(branch("dev-two"))' -d dev-one --keepbranches
  rebasing 5:bc8139ee757c "dev-one named branch"
  note: rebase of 5:bc8139ee757c created no changes to commit
  rebasing 6:42aa3cf0fa7a "F"
  rebasing 7:1a1e6f72ec38 "G"
  rebasing 8:904590360559 "H"
  rebasing 9:59c2e59309fe "dev-two named branch"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/bc8139ee757c-f11c1080-rebase.hg

  $ hg tglog
  o  9: 71325f8bc082 'dev-two named branch' dev-two
  |
  o  8: 12b2bc666e20 'H'
  |
  | o  7: 549f007a9f5f 'G'
  |/|
  o |  6: 679f28760620 'F'
  | |
  @ |  5: 643fc9128048 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  | |
  o |  3: 32af7686d403 'D'
  | |
  o |  2: 5fddd98957c8 'C'
  | |
  o |  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg rebase -s 'max(branch("dev-one"))' -d 0 --keepbranches
  rebasing 5:643fc9128048 "dev-one named branch"
  rebasing 6:679f28760620 "F"
  rebasing 7:549f007a9f5f "G"
  rebasing 8:12b2bc666e20 "H"
  rebasing 9:71325f8bc082 "dev-two named branch" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/643fc9128048-6cdd1a52-rebase.hg

  $ hg tglog
  o  9: 3944801ae4ea 'dev-two named branch' dev-two
  |
  o  8: 8e279d293175 'H'
  |
  | o  7: aeefee77ab01 'G'
  |/|
  o |  6: e908b85f3729 'F'
  | |
  @ |  5: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  4: 9520eea781bc 'E'
  |/
  | o  3: 32af7686d403 'D'
  | |
  | o  2: 5fddd98957c8 'C'
  | |
  | o  1: 42ccdea3bb16 'B'
  |/
  o  0: cd010b8cd998 'A'
  
  $ hg up -r 0 > /dev/null

Rebasing descendant onto ancestor across different named branches

  $ hg rebase -s 1 -d 9 --keepbranches
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/42ccdea3bb16-3cb021d3-rebase.hg

  $ hg tglog
  o  9: e9f862ce8bad 'D'
  |
  o  8: a0d543090fa4 'C'
  |
  o  7: 3bdb949809d9 'B'
  |
  o  6: 3944801ae4ea 'dev-two named branch' dev-two
  |
  o  5: 8e279d293175 'H'
  |
  | o  4: aeefee77ab01 'G'
  |/|
  o |  3: e908b85f3729 'F'
  | |
  o |  2: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  1: 9520eea781bc 'E'
  |/
  @  0: cd010b8cd998 'A'
  
  $ hg rebase -s 5 -d 6
  abort: source and destination form a cycle
  [255]

  $ hg rebase -s 6 -d 5
  rebasing 6:3944801ae4ea "dev-two named branch"
  rebasing 7:3bdb949809d9 "B"
  rebasing 8:a0d543090fa4 "C"
  rebasing 9:e9f862ce8bad "D" (tip)
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/3944801ae4ea-fb46ed74-rebase.hg

  $ hg tglog
  o  9: e522577ccdbd 'D'
  |
  o  8: 810110211f50 'C'
  |
  o  7: 160b0930ccc6 'B'
  |
  o  6: c57724c84928 'dev-two named branch'
  |
  o  5: 8e279d293175 'H'
  |
  | o  4: aeefee77ab01 'G'
  |/|
  o |  3: e908b85f3729 'F'
  | |
  o |  2: bc8139ee757c 'dev-one named branch' dev-one
  | |
  | o  1: 9520eea781bc 'E'
  |/
  @  0: cd010b8cd998 'A'
  

Reopen branch by rebase

  $ hg up -qr3
  $ hg branch -q b
  $ hg ci -m 'create b'
  $ hg ci -m 'close b' --close
  $ hg rebase -b 8 -d b
  reopening closed branch head 2b586e70108d
  rebasing 5:8e279d293175 "H"
  rebasing 6:c57724c84928 "dev-two named branch"
  rebasing 7:160b0930ccc6 "B"
  rebasing 8:810110211f50 "C"
  rebasing 9:e522577ccdbd "D"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/8e279d293175-b023e27c-rebase.hg

  $ cd ..

Rebase to other head on branch

Set up a case:

  $ hg init case1
  $ cd case1
  $ touch f
  $ hg ci -qAm0
  $ hg branch -q b
  $ echo >> f
  $ hg ci -qAm 'b1'
  $ hg up -qr -2
  $ hg branch -qf b
  $ hg ci -qm 'b2'
  $ hg up -qr -3
  $ hg branch -q c
  $ hg ci -m 'c1'

  $ hg tglog
  @  3: c062e3ecd6c6 'c1' c
  |
  | o  2: 792845bb77ee 'b2' b
  |/
  | o  1: 40039acb7ca5 'b1' b
  |/
  o  0: d681519c3ea7 '0'
  
  $ hg clone -q . ../case2

rebase 'b2' to another lower branch head

  $ hg up -qr 2
  $ hg rebase
  rebasing 2:792845bb77ee "b2"
  note: rebase of 2:792845bb77ee created no changes to commit
  saved backup bundle to $TESTTMP/case1/.hg/strip-backup/792845bb77ee-627120ee-rebase.hg
  $ hg tglog
  o  2: c062e3ecd6c6 'c1' c
  |
  | @  1: 40039acb7ca5 'b1' b
  |/
  o  0: d681519c3ea7 '0'
  

rebase 'b1' on top of the tip of the branch ('b2') - ignoring the tip branch ('c1')

  $ cd ../case2
  $ hg up -qr 1
  $ hg rebase
  rebasing 1:40039acb7ca5 "b1"
  saved backup bundle to $TESTTMP/case2/.hg/strip-backup/40039acb7ca5-342b72d1-rebase.hg
  $ hg tglog
  @  3: 76abc1c6f8c7 'b1' b
  |
  | o  2: c062e3ecd6c6 'c1' c
  | |
  o |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  

rebase 'c1' to the branch head 'c2' that is closed

  $ hg branch -qf c
  $ hg ci -qm 'c2 closed' --close
  $ hg up -qr 2
  $ hg tglog
  _  4: 8427af5d86f2 'c2 closed' c
  |
  o  3: 76abc1c6f8c7 'b1' b
  |
  | @  2: c062e3ecd6c6 'c1' c
  | |
  o |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  
  $ hg rebase
  abort: branch 'c' has one head - please rebase to an explicit rev
  (run 'hg heads' to see all heads)
  [255]
  $ hg tglog
  _  4: 8427af5d86f2 'c2 closed' c
  |
  o  3: 76abc1c6f8c7 'b1' b
  |
  | @  2: c062e3ecd6c6 'c1' c
  | |
  o |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  

  $ hg up -cr 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch x
  marked working directory as branch x
  $ hg rebase -r 3:: -d .
  rebasing 3:76abc1c6f8c7 "b1"
  rebasing 4:8427af5d86f2 "c2 closed" (tip)
  note: rebase of 4:8427af5d86f2 created no changes to commit
  saved backup bundle to $TESTTMP/case2/.hg/strip-backup/76abc1c6f8c7-cd698d13-rebase.hg
  $ hg tglog
  o  3: 117b0ed08075 'b1' x
  |
  | o  2: c062e3ecd6c6 'c1' c
  | |
  @ |  1: 792845bb77ee 'b2' b
  |/
  o  0: d681519c3ea7 '0'
  

  $ cd ..