Fix #1232

ooxml/XWPF/Usermodel/XWPFSharedRun.cs

@@ -152,7 +152,26 @@ public String GetFontFamily(FontCharRange fcr)
             }
         }
 
-        public double FontSize { get; set; }
+        public double FontSize 
+        {
+            get
+            {
+                OpenXmlFormats.Wordprocessing.CT_RPr pr = run.rPr1;
+                return (pr != null && pr.IsSetSz()) ? pr.sz.val / 2.0 : -1;
+            }
+            set
+            {
+                OpenXmlFormats.Wordprocessing.CT_RPr pr = run.IsSetRPr1() ? run.rPr1 : run.AddNewRPr1();
+                if(value < 1)
+                {
+                    // fix for TestBug58922() in NPOI
+                    pr.sz = null; // unset
+                    return;
+                }
+                OpenXmlFormats.Wordprocessing.CT_HpsMeasure ctSize = pr.IsSetSz() ? pr.sz : pr.AddNewSz();
+                ctSize.val = (ulong) (value * 2);
+            }
+        }
 
         public string Text
         {

testcases/ooxml/XWPF/UserModel/TestXWPFSharedRun.cs

@@ -0,0 +1,38 @@
+using NPOI.OpenXmlFormats.Shared;
+using NPOI.XWPF.Usermodel;
+using NPOI.XWPF.UserModel;
+using NUnit.Framework;
+
+namespace TestCases.XWPF.UserModel
+{
+    public class TestXWPFSharedRun
+    {
+        private CT_R ctRun;
+        public IRunBody p;
+
+        [SetUp]
+        public void SetUp()
+        {
+            XWPFDocument doc = new XWPFDocument();
+            p = doc.CreateParagraph();
+
+            this.ctRun = new CT_R();
+        }
+
+        [Test]
+        public void TestSetGetFontSize()
+        {
+            NPOI.OpenXmlFormats.Wordprocessing.CT_RPr rpr = ctRun.AddNewRPr1();
+            rpr.AddNewSz().val = 14;
+
+            XWPFSharedRun run = new XWPFSharedRun(ctRun, p);
+            Assert.AreEqual(7.0, run.FontSize);
+
+            run.FontSize = 24;
+            Assert.AreEqual(48, (int) rpr.sz.val);
+
+            run.FontSize = 24.5;
+            Assert.AreEqual(24.5, run.FontSize);
+        }
+    }
+}