Fix bug in making sure catalog is contiguous

LoadIndexedReferenceObjectsTask.loadSkyCircle could return
a catalog that was not contigous (despite code that attempted
to guarantee otherwise). Add tests for this to test_htmIndex.py.

Also document that the catalogs returned by
LoadIndexedReferenceObjectsTask.loadSkyCircle and loadSkyBox
are always contiguous.

python/lsst/meas/algorithms/loadIndexedReferenceObjects.py

@@ -84,10 +84,6 @@ def loadSkyCircle(self, ctrCoord, radius, filterName=None, epoch=None):
             else:
                 refCat.extend(shard)
 
-        # make sure catalog is contiguous
-        if not refCat.isContiguous():
-            refCat = refCat.copy()
-
         if epoch is not None:
             self.applyProperMotions(refCat, epoch)
 
@@ -104,6 +100,10 @@ def loadSkyCircle(self, ctrCoord, radius, filterName=None, epoch=None):
         expandedCat.extend(refCat, mapper=mapper)
         del refCat  # avoid accidentally returning the unexpanded reference catalog
 
+        # make sure catalog is contiguous
+        if not expandedCat.isContiguous():
+            expandedCat = expandedCat.copy(True)
+
         # return reference catalog
         return pipeBase.Struct(
             refCat=expandedCat,

python/lsst/meas/algorithms/loadReferenceObjects.py

@@ -240,6 +240,7 @@ def loadPixelBox(self, bbox, wcs, filterName=None, calib=None, epoch=None):
             @link meas_algorithms_loadReferenceObjects_Schema standard schema @endlink
             as documented in LoadReferenceObjects, including photometric, resolved and variable;
             hasCentroid is False for all objects.
+            The catalog is guaranteed to be contiguous.
         - fluxField = name of flux field for specified filterName
         """
         circle = self._calculateCircle(bbox, wcs)
@@ -283,6 +284,7 @@ def loadSkyCircle(self, ctrCoord, radius, filterName=None, epoch=None):
             @link meas_algorithms_loadReferenceObjects_Schema standard schema @endlink
             as documented in LoadReferenceObjects, including photometric, resolved and variable;
             hasCentroid is False for all objects.
+            The catalog is guaranteed to be contiguous.
         - fluxField = name of flux field for specified filterName
         """
         return

tests/test_htmIndex.py

@@ -369,16 +369,18 @@ def testIngest(self):
         config = LoadIndexedReferenceObjectsConfig()
         config.ref_dataset_name = "myrefcat"
         loader = LoadIndexedReferenceObjectsTask(butler=butler, config=config)
-        cat = loader.loadSkyCircle(cent, self.search_radius, filterName='a')
+        cat = loader.loadSkyCircle(cent, self.search_radius, filterName='a').refCat
         self.assertTrue(len(cat) > 0)
+        self.assertTrue(cat.isContiguous())
 
         # test that a catalog can be loaded even with a name not used for ingestion
         butler = dafPersist.Butler(self.test_repo_path)
         config = LoadIndexedReferenceObjectsConfig()
         config.ref_dataset_name = self.test_dataset_name
         loader = LoadIndexedReferenceObjectsTask(butler=butler, config=config)
-        cat = loader.loadSkyCircle(cent, self.search_radius, filterName='a')
+        cat = loader.loadSkyCircle(cent, self.search_radius, filterName='a').refCat
         self.assertTrue(len(cat) > 0)
+        self.assertTrue(cat.isContiguous())
 
     def testLoadIndexedReferenceConfig(self):
         """Make sure LoadIndexedReferenceConfig has needed fields."""
@@ -395,6 +397,7 @@ def testLoadSkyCircle(self):
         for tupl, idList in self.comp_cats.items():
             cent = make_coord(*tupl)
             lcat = loader.loadSkyCircle(cent, self.search_radius, filterName='a')
+            self.assertTrue(lcat.refCat.isContiguous())
             self.assertFalse("camFlux" in lcat.refCat.schema)
             self.assertEqual(Counter(lcat.refCat['id']), Counter(idList))
             if len(lcat.refCat) > 0: