DM-31027: Fix buffer overrun in getMaskPropagationThreshold and add tests.

src/math/Statistics.cc

@@ -726,7 +726,7 @@ std::shared_ptr<std::vector<typename ImageT::Pixel> > makeVectorCopy(ImageT cons
 
 double StatisticsControl::getMaskPropagationThreshold(int bit) const {
     int oldSize = _maskPropagationThresholds.size();
-    if (oldSize < bit) {
+    if (oldSize <= bit) {
         return 1.0;
     }
     return _maskPropagationThresholds[bit];

tests/test_maskPropagationThreshold.py

@@ -0,0 +1,57 @@
+# This file is part of afw.
+#
+# Developed for the LSST Data Management System.
+# This product includes software developed by the LSST Project
+# (https://www.lsst.org).
+# See the COPYRIGHT file at the top-level directory of this distribution
+# for details of code ownership.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+"""Tests for statsCtrl mask propagation thresholds."""
+import unittest
+
+import lsst.utils.tests
+import lsst.afw.math as afwMath
+
+
+class PropagationThresholdTestCase(lsst.utils.tests.TestCase):
+    """Testing for propagation thresholds."""
+    def testEmpty(self):
+        """Test retrieving an empty threshold."""
+        statsCtrl = afwMath.StatisticsControl()
+        self.assertEqual(statsCtrl.getMaskPropagationThreshold(0), 1.0)
+
+    def testSetSingle(self):
+        """Test setting and retrieving a single threshold."""
+        statsCtrl = afwMath.StatisticsControl()
+        statsCtrl.setMaskPropagationThreshold(1, 0.1)
+
+        for bit in range(32):
+            if bit == 1:
+                self.assertEqual(statsCtrl.getMaskPropagationThreshold(bit), 0.1)
+            else:
+                self.assertEqual(statsCtrl.getMaskPropagationThreshold(bit), 1.0)
+
+
+class TestMemory(lsst.utils.tests.MemoryTestCase):
+    pass
+
+
+def setup_module(module):
+    lsst.utils.tests.init()
+
+
+if __name__ == "__main__":
+    lsst.utils.tests.init()
+    unittest.main()