Issue #7048: logb should round its result when that result doesn't fit
into the available precision.  (Tests for this change are included in
the most recent set of testcases from the Decimal Specification site;
those testcases will be updated shortly.)
diff --git a/Misc/NEWS b/Misc/NEWS
index f90c8f4..cbd3040 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -398,6 +398,9 @@
 Library
 -------
 
+- Issue #7048: Force Decimal.logb to round its result when that result
+  is too large to fit in the current precision.
+
 - Issue #6516: Added owner/group support when creating tar archives in 
   Distutils.