Fix a ClassCastException reported on mailing list.
diff --git a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/SpecializableTransform.java b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/SpecializableTransform.java
index 1d9e306..d86fa95 100644
--- a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/SpecializableTransform.java
+++ b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/transform/SpecializableTransform.java
@@ -254,7 +254,15 @@
* we do not know what was the last search result.
*/
private SubArea locate(final DirectPosition pos) {
- return (SubArea) RTreeNode.locate(domains, pos);
+ /*
+ * All nodes should be SubArea instances, except in some circumstances the root node.
+ * That root node may returned by `RTreeNode.locate(…)` if given position is inside
+ * the union of all bounding boxes, but not in the bounding box of any specific grid.
+ * In such case the caller will fallback on `DatumShiftGridGroup.interpolateInCell(…)`
+ * which perform a more extensive search for the nearest grid.
+ */
+ final RTreeNode node = RTreeNode.locate(domains, pos);
+ return (node instanceof SubArea) ? (SubArea) node : null;
}
/**
