Avoid NPE with malformed EscherAggregate

poi/src/main/java/org/apache/poi/hssf/record/EscherAggregate.java

@@ -292,6 +292,9 @@ public final class EscherAggregate extends AbstractEscherHolderRecord {
 
             // Write the matching OBJ record
             Record obj = shapeToObj.get(shapes.get(i));
+            if (obj == null) {
+                throw new IllegalStateException("Cannot serialize EscherAggregate with missing shape-object");
+            }
             pos += obj.serialize(pos, data);
 
             isFirst = false;

poi/src/test/java/org/apache/poi/hssf/dev/TestBiffViewer.java

@@ -49,6 +49,7 @@ class TestBiffViewer extends BaseTestIteratingXLS {
         excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-6483562584932352.xls", IndexOutOfBoundsException.class);
         excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-5816431116615680.xls", RecordFormatException.class);
         excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-4734163573080064.xls", IndexOutOfBoundsException.class);
+        excludes.put("cf9f845e73447b092477d0472402a5baea4b8c9f.xls", RecordFormatException.class);
 
         return excludes;
     }

poi/src/test/java/org/apache/poi/hssf/dev/TestRecordLister.java

@@ -52,6 +52,7 @@ class TestRecordLister extends BaseTestIteratingXLS {
         excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-6483562584932352.xls", RecordFormatException.class);
         excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-5816431116615680.xls", RecordFormatException.class);
         excludes.put("clusterfuzz-testcase-minimized-POIHSSFFuzzer-4734163573080064.xls", IndexOutOfBoundsException.class);
+        excludes.put("cf9f845e73447b092477d0472402a5baea4b8c9f.xls", RecordFormatException.class);
 
         return excludes;
     }

poi/src/test/java/org/apache/poi/hssf/model/TestDrawingAggregate.java

@@ -138,7 +138,8 @@ class TestDrawingAggregate {
                 filter(file ->
                         !file.getName().equals("clusterfuzz-testcase-minimized-POIHSSFFuzzer-5285517825277952.xls") &&
                         !file.getName().equals("clusterfuzz-testcase-minimized-POIHSSFFuzzer-4977868385681408.xls") &&
-                        !file.getName().equals("crash-e329fca9087fe21bca4a80c8bc472a661c98d860.xls")).
+                        !file.getName().equals("crash-e329fca9087fe21bca4a80c8bc472a661c98d860.xls") &&
+                        !file.getName().equals("cf9f845e73447b092477d0472402a5baea4b8c9f.xls")).
                 map(Arguments::of);
     }