Adds proper handling of empty properties in CssFontFaceRule

DEVSIX-6339

Autoported commit.
Original commit hash: [aaf9dee82]

Author: glenn.volckaert

itext/itext.styledxmlparser/itext/styledxmlparser/css/CssFontFaceRule.cs

@@ -60,6 +60,9 @@ public CssFontFaceRule()
         /// <summary>Gets the properties.</summary>
         /// <returns>the properties</returns>
         public virtual IList<CssDeclaration> GetProperties() {
+            if (properties == null) {
+                return new List<CssDeclaration>();
+            }
             return new List<CssDeclaration>(properties);
         }
 
@@ -76,7 +79,7 @@ public override void AddBodyCssDeclarations(IList<CssDeclaration> cssDeclaration
         public override String ToString() {
             StringBuilder sb = new StringBuilder();
             sb.Append("@").Append(GetRuleName()).Append(" {").Append("\n");
-            foreach (CssDeclaration declaration in properties) {
+            foreach (CssDeclaration declaration in GetProperties()) {
                 sb.Append("    ");
                 sb.Append(declaration);
                 sb.Append(";\n");

port-hash

@@ -1 +1 @@
-32b7cef68810f31fbac4035995430d0d6025ce76
+aaf9dee82b3f93db0f1e8367a6aa18f62cbe77d7