windows: allow readpipe() to actually read data out of the pipe It appears that the read() in readpipe() never actually ran before (in test-ssh.t anyway). A print of the size returned from os.fstat() is 0 for every single print output in test-ssh.t, so the data in the pipe ends up being read later instead of when it is available. This is the same problem as Linux, as mentioned in 331cbf088c4c. There are several places in the Windows SSH tests where the order of local output vs remote output differ from the other platforms. This only fixes one of those cases (and interstingly, not the one added in order to test 331cbf088c4c), so there is more investigation needed. However, without this patch, test-ssh.t also has this diff: --- c:/Users/Matt/Projects/hg/tests/test-ssh.t +++ c:/Users/Matt/Projects/hg/tests/test-ssh.t.err @@ -397,11 +397,11 @@ $ hg push --ssh "sh ../ssh.sh" pushing to ssh://user@dummy/*/remote (glob) searching for changes - remote: Permission denied - remote: abort: prechangegroup.hg-ssh hook failed - remote: Permission denied - remote: pushkey-abort: prepushkey.hg-ssh hook failed updating 6c0482d977a3 to public failed! + remote: Permission denied + remote: abort: prechangegroup.hg-ssh hook failed + remote: Permission denied + remote: pushkey-abort: prepushkey.hg-ssh hook failed [1] $ cd .. Output with this change was stable over 600+ runs of test-ssh.t. I initially tried a background thread to read the pipe[1], but this was simpler and the test results were exactly the same. I also tried SetNamedPipeHandleState(), but the PIPE_NOWAIT is for compatibility with LANMAN 2.0, not for async I/O (the results were identical though). [1] http://eyalarubas.com/python-subproc-nonblock.html

win32: add a method to fetch the available pipe data size This will be used in the next patch to do nonblocking reads from the child process, like on posix platforms. See that for why os.fstat() is insufficient.

dirs._addpath: reinstate use of Py_CLEAR I changed this to an explicit Py_DECREF + set to null in 6f0e6fa9fdd7. This was a silly misunderstanding on my part -- for some reason I thought Py_CLEAR set its argument to null only if its refcount reached 0. Turns out that's not actually the case -- Py_CLEAR is just Py_DECREF + set to null with some additional precautions around destructors that aren't relevant here. The real bug that 6f0e6fa9fdd7 fixed was the fact that we were mutating the string after setting it in the Python dictionary.