Bug 66425: Avoid a ClassCastException found via oss-fuzz

Add exception details and fix expected exceptions to make tests run again

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1911503 13f79535-47bb-0310-9956-ffa450edef68

poi-ooxml/src/main/java/org/apache/poi/xwpf/usermodel/XWPFDocument.java

@@ -286,7 +286,7 @@ public class XWPFDocument extends POIXMLDocument implements Document, IBody {
                         }
                     }
                 } catch (ClassCastException e) {
-                    throw new IllegalArgumentException("Relation and type of document-part did not match, had relation " + relation + " and type of document-part: " + p.getClass());
+                    throw new IllegalArgumentException("Relation and type of document-part did not match, had relation " + relation + " and type of document-part: " + p.getClass(), e);
                 }
             }
             initHyperlinks();

poi-scratchpad/src/main/java/org/apache/poi/hsmf/datatypes/Chunks.java

@@ -251,7 +251,7 @@ public final class Chunks implements ChunkGroupWithProperties {
             allChunks.computeIfAbsent(prop, k -> new ArrayList<>());
             allChunks.get(prop).add(chunk);
         } catch (ClassCastException e) {
-            throw new IllegalArgumentException("Property and type of chunk did not match, had property " + prop + " and type of chunk: " + chunk.getClass());
+            throw new IllegalArgumentException("Property and type of chunk did not match, had property " + prop + " and type of chunk: " + chunk.getClass(), e);
         }
     }