view tests/test-bundle-type.t @ 26375:3686fa2b8eee

windows: insert file positioning call between reads and writes

fopen() and fdopen() have a unique-to-Windows requirement that
transitions between read and write operations in files opened
in modes r+, w+, and a+ perform a file positioning call
(fsetpos, fseek, or rewind) in between. While the MSDN docs don't
say what will happen if this is not done, observations reveal
that Python raises an IOError with errno 0. Furthermore, I
/think/ this behavior isn't deterministic. But I can reproduce
it reliably with subsequent patches applied that open revlogs
in a+ mode and perform both reads and writes.

This patch introduces a proxy class for file handles opened
in r+, w+, and a+ mode on Windows. The class intercepts calls
and audits whether a file positioning function has been called
between read and write operations. If not, a dummy, no-op seek
to the current file position is performed. This appears to be
sufficient to "trick" Windows into allowing transitions between
read and writes without raising errors.

bundle w/o type option

  $ hg init t1
  $ hg init t2
  $ cd t1
  $ echo blablablablabla > file.txt
  $ hg ci -Ama
  adding file.txt
  $ hg log | grep summary
  summary:     a
  $ hg bundle ../b1 ../t2
  searching for changes
  1 changesets found

  $ cd ../t2
  $ hg pull ../b1
  pulling from ../b1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log | grep summary
  summary:     a
  $ cd ..

test bundle types

  $ for t in "None" "bzip2" "gzip"; do
  >   echo % test bundle type $t
  >   hg init t$t
  >   cd t1
  >   hg bundle -t $t ../b$t ../t$t
  >   cut -b 1-6 ../b$t | head -n 1
  >   cd ../t$t
  >   hg pull ../b$t
  >   hg up
  >   hg log | grep summary
  >   cd ..
  > done
  % test bundle type None
  searching for changes
  1 changesets found
  HG10UN
  pulling from ../bNone
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  summary:     a
  % test bundle type bzip2
  searching for changes
  1 changesets found
  HG10BZ
  pulling from ../bbzip2
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  summary:     a
  % test bundle type gzip
  searching for changes
  1 changesets found
  HG10GZ
  pulling from ../bgzip
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  summary:     a

test garbage file

  $ echo garbage > bgarbage
  $ hg init tgarbage
  $ cd tgarbage
  $ hg pull ../bgarbage
  pulling from ../bgarbage
  abort: ../bgarbage: not a Mercurial bundle
  [255]
  $ cd ..

test invalid bundle type

  $ cd t1
  $ hg bundle -a -t garbage ../bgarbage
  abort: unknown bundle type specified with --type
  [255]
  $ cd ..