Bug 65099: Fix incorrect handling of styles in XWPFStyle.getUsedStyleList

Closes github #216

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1886063 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/xwpf/usermodel/XWPFStyles.java

         String nextStyleID = style.getNextStyleID();
         XWPFStyle nextStyle = getStyle(nextStyleID);
         if ((nextStyle != null) && (!usedStyleList.contains(nextStyle))) {
-            usedStyleList.add(linkStyle);
-            getUsedStyleList(linkStyle, usedStyleList);
+            usedStyleList.add(nextStyle);
+            getUsedStyleList(nextStyle, usedStyleList);
         }
         return usedStyleList;
     }

src/ooxml/testcases/org/apache/poi/xwpf/usermodel/TestXWPFBugs.java

 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.math.BigInteger;
+import java.util.List;
 
 import org.apache.poi.util.Units;
 import org.apache.poi.xwpf.XWPFTestDataSamples;
 
         documentNumbering.addNum(abstractNumID);
     }
+
+    @Test
+    public void test65099() throws IOException {
+        try (XWPFDocument doc = XWPFTestDataSamples.openSampleDocument("65099.docx")) {
+            XWPFStyles styles = doc.getStyles();
+            assertNotNull(styles);
+
+            XWPFStyle normal = styles.getStyle("Normal");
+            assertNotNull(normal);
+
+            XWPFStyle style1 = styles.getStyle("EdfTitre3Car");
+            assertNotNull(style1);
+
+            List<XWPFStyle> list = styles.getUsedStyleList(normal);
+            assertNotNull(list);
+            assertEquals(1, list.size());
+
+            list = styles.getUsedStyleList(style1);
+            assertNotNull(list);
+            assertEquals(7, list.size());
+
+            assertThrows(NullPointerException.class,
+                    () -> styles.getUsedStyleList(null),
+                    "Pasisng in 'null' triggers an exception");
+
+            XWPFStyle style = doc.getStyles().getStyle("TableauGrille41");
+            doc.getStyles().getUsedStyleList(style);
+        }
+    }
 }

src/ooxml/testcases/org/apache/poi/xwpf/usermodel/TestXWPFStyles.java

                 assertNull(r.getColor());
                 assertNull(r.getFontFamily());
                 assertNull(r.getFontName());
-                assertEquals(-1, r.getFontSize());
+                assertNull(r.getFontSizeAsDouble());
             }
 
             // On page two, has explicit styles, but on runs not on
                 XWPFRun r = p.getRuns().get(0);
                 assertEquals("Arial Black", r.getFontFamily());
                 assertEquals("Arial Black", r.getFontName());
-                assertEquals(16, r.getFontSize());
+                assertEquals(16.0, r.getFontSizeAsDouble(), 0.01);
                 assertEquals("548DD4", r.getColor());
             }
 
             assertNotNull(styles.getDefaultRunStyle());
             assertNotNull(styles.getDefaultParagraphStyle());
 
-            assertEquals(11, styles.getDefaultRunStyle().getFontSize());
+            assertEquals(11.0, styles.getDefaultRunStyle().getFontSizeAsDouble(), 0.01);
             assertEquals(11.0, styles.getDefaultRunStyle().getFontSizeAsDouble(), 0.01);
             assertEquals(200, styles.getDefaultParagraphStyle().getSpacingAfter());
         }