Issue #25902: Fixed various refcount issues in ElementTree iteration.

diff --cc Lib/test/test_xml_etree.py
Simple merge

diff --cc Lib/xml/etree/ElementTree.py
Simple merge

diff --cc Misc/NEWS
index 01cf6729b55e2bcb2cb53fd92d31d547fb6e3b7e,90adba8eb8ee86fbd21a0d62b96961d179aef5e8..ad37eb7874160359a9470ab90732c5cab066adfe
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -115,14 -28,8 +115,16 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #25902: Fixed various refcount issues in ElementTree iteration.
+ 
 +- Issue #22227: The TarFile iterator is reimplemented using generator.
 +  This implementation is simpler that using class.
 +
 +- Issue #25638: Optimized ElementTree.iterparse(); it is now 2x faster.
 +  Optimized ElementTree parsing; it is now 10% faster.
 +
 +- Issue #25761: Improved detecting errors in broken pickle data.
 +
  - Issue #25717: Restore the previous behaviour of tolerating most fstat()
    errors when opening files.  This was a regression in 3.5a1, and stopped
    anonymous temporary files from working in special cases.

diff --cc Modules/_elementtree.c
Simple merge