[Cython] Control Flow

[Stefan Behnel]

Vitja,

here are some more quirks, but they are minor issues. I'll commit my 
changes to lxml to keep it working, and then merge in the branch. It's 
certainly in a "good enough for a merge" state.

I'm actually surprised how few problems I had to fix, given how old the 
code in lxml is by now. Let's see how much of Sage we break.

Stefan


Some more issues:

     cdef Py_ssize_t c = 0, i
     [...]
     while c_node is not NULL and c < count:
         for i from 0 <= i < step:
             c_next = next_element(c_next)
         _removeNode(doc, c_node)
         c = c + 1
         c_node = c_next
     return 0

src/lxml/apihelpers.pxi:1079:23: Unused entry 'i'

(Although the best fix is to change the code to for-in-range() here...)


Here's another interesting constellation:

         live_refs = _convert_xslt_parameters(transform_ctxt, kw, &params)
         c_result = self._run_transform(
             c_doc, params, context, transform_ctxt)
         if params is not NULL:
             # deallocate space for parameters
             python.PyMem_Free(params)
         live_refs = None   # release objects

src/lxml/xslt.pxi:519:22: Unused entry 'live_refs'

So, holding on to Python references to keep their C char* alive gives me a 
warning. Fine. I guess I'll have to live with that...


Another missing bit:

     cdef void registerExsltFunctions(self):
         cdef xpath.xmlXPathContext* ctxt = self._xpathCtxt
         cdef int i
         cdef char* c_href
         if xslt.LIBXSLT_VERSION < 10125:
             # we'd only execute dummy functions anyway
             return
         tree.xmlHashScan(
             self._xpathCtxt.nsHash, _registerExsltFunctionsForNamespaces,
             self._xpathCtxt)

src/lxml/xpath.pxi:80:34: Unused entry 'ctxt'

Ok, right, "ctxt" is unused here. But all *3* declarations are actually 
left-over code from the last refactoring. None of them is used, and I only 
get one warning?