patch to guard against bad return numbers

PDAL_bad_return_numbers.patch

@@ -0,0 +1,14 @@
+diff --git a/io/private/las/Summary.cpp b/io/private/las/Summary.cpp
+index e9232d4806..91059bfaf9 100644
+--- a/io/private/las/Summary.cpp
++++ b/io/private/las/Summary.cpp
+@@ -57,7 +57,8 @@ void Summary::addPoint(double x, double y, double z, int returnNumber)
+     m_bounds.grow(x, y, z);
+ 
+     // Returns numbers are indexed from one, but the array indexes from 0.
+-    m_returnCounts[returnNumber - 1]++;
++    if (returnNumber >= 1 && returnNumber <= m_returnCounts.size())
++        m_returnCounts[returnNumber - 1]++;
+ }
+ 
+