view tests/test-oldcgi.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.

#require no-msys # MSYS will translate web paths as if they were file paths

This tests if CGI files from before d0db3462d568 still work.

  $ hg init test
  $ cat >hgweb.cgi <<HGWEB
  > #!/usr/bin/env python
  > #
  > # An example CGI script to use hgweb, edit as necessary
  > 
  > import cgitb, os, sys
  > cgitb.enable()
  > 
  > # sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
  > from mercurial import hgweb
  > 
  > h = hgweb.hgweb("test", "Empty test repository")
  > h.run()
  > HGWEB

  $ chmod 755 hgweb.cgi

  $ cat >hgweb.config <<HGWEBDIRCONF
  > [paths]
  > test = test
  > HGWEBDIRCONF

  $ cat >hgwebdir.cgi <<HGWEBDIR
  > #!/usr/bin/env python
  > #
  > # An example CGI script to export multiple hgweb repos, edit as necessary
  > 
  > import cgitb, sys
  > cgitb.enable()
  > 
  > # sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
  > from mercurial import hgweb
  > 
  > # The config file looks like this.  You can have paths to individual
  > # repos, collections of repos in a directory tree, or both.
  > #
  > # [paths]
  > # virtual/path = /real/path
  > # virtual/path = /real/path
  > #
  > # [collections]
  > # /prefix/to/strip/off = /root/of/tree/full/of/repos
  > #
  > # collections example: say directory tree /foo contains repos /foo/bar,
  > # /foo/quux/baz.  Give this config section:
  > #   [collections]
  > #   /foo = /foo
  > # Then repos will list as bar and quux/baz.
  > 
  > # Alternatively you can pass a list of ('virtual/path', '/real/path') tuples
  > # or use a dictionary with entries like 'virtual/path': '/real/path'
  > 
  > h = hgweb.hgwebdir("hgweb.config")
  > h.run()
  > HGWEBDIR

  $ chmod 755 hgwebdir.cgi

  $ . "$TESTDIR/cgienv"
  $ python hgweb.cgi > page1
  $ python hgwebdir.cgi > page2

  $ PATH_INFO="/test/"
  $ PATH_TRANSLATED="/var/something/test.cgi"
  $ REQUEST_URI="/test/test/"
  $ SCRIPT_URI="http://hg.omnifarious.org/test/test/"
  $ SCRIPT_URL="/test/test/"
  $ python hgwebdir.cgi > page3

  $ grep -i error page1 page2 page3
  [1]