[Python-checkins] Add NEWS entry for opcode tracing change. (GH-4045)

[Nick Coghlan]

https://github.com/python/cpython/commit/05a634b12a8207611ae8e9d051427d615fcacb69
commit: 05a634b12a8207611ae8e9d051427d615fcacb69
branch: master
author: George King <george.w.king at gmail.com>
committer: Nick Coghlan <ncoghlan at gmail.com>
date: 2017-10-19T17:41:59+10:00
summary:

Add NEWS entry for opcode tracing change. (GH-4045)

files:
A Misc/NEWS.d/next/Core and Builtins/2017-10-18-19-41-12.bpo-31618.liLDiS.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2017-10-18-19-41-12.bpo-31618.liLDiS.rst b/Misc/NEWS.d/next/Core and Builtins/2017-10-18-19-41-12.bpo-31618.liLDiS.rst
new file mode 100644
index 00000000000..5a8d3418a79
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2017-10-18-19-41-12.bpo-31618.liLDiS.rst	
@@ -0,0 +1,7 @@
+The per-frame tracing logic added in 3.7a1 has been altered so that
+``frame->f_lineno`` is updated before either ``"line"`` or ``"opcode"``
+events are emitted. Previously, opcode events were emitted first, and
+therefore would occasionally see stale line numbers on the frame. The
+behavior of this feature has changed slightly as a result: when both
+``f_trace_lines`` and ``f_trace_opcodes`` are enabled, line events now occur
+first.