Fix recognition of network paths in UrlUtil, add test

DEVSIX-1670

Author: LodrKumquat

itext.tests/itext.layout.tests/itext/layout/NetWorkPathTest.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using iText.IO.Image;
+using iText.Layout.Element;
+
+namespace iText.Layout
+{
+    // This test is present only in c#
+    class NetWorkPathTest
+    {
+        [NUnit.Framework.Test]
+        public virtual void NetworkPathImageTest()
+        {
+            var fullImagePath = @"\\someVeryRandomWords\SomeVeryRandomName.img";
+            string startOfMsg = null;
+            Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
+            Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture;
+            try
+            {
+                Image drawing = new Image(ImageDataFactory.Create(fullImagePath));
+            }
+            catch (Exception e)
+            {
+                if (e.InnerException != null && e.InnerException.Message.Length > 18)
+                    startOfMsg = e.InnerException.Message.Substring(0, 19);
+            }
+            NUnit.Framework.Assert.IsNotNull(startOfMsg);
+            NUnit.Framework.Assert.AreNotEqual("Could not find file", startOfMsg);
+        }
+    }
+}

itext/itext.io/itext/io/source/RandomAccessSourceFactory.cs

@@ -153,7 +153,7 @@ public IRandomAccessSource CreateSource(FileStream raf)
 		/// <exception cref="System.IO.IOException"/>
         public IRandomAccessSource CreateSource(Uri url) {
 #if !NETSTANDARD1_6
-            WebRequest wr = WebRequest.Create(Uri.UnescapeDataString(url.AbsoluteUri));
+            WebRequest wr = WebRequest.Create(url.LocalPath);
             wr.Credentials = CredentialCache.DefaultCredentials;
             Stream isp = wr.GetResponse().GetResponseStream();
 #else

itext/itext.io/itext/io/util/UrlUtil.cs

@@ -71,7 +71,9 @@ public static Uri ToURL(String filename) {
         public static Stream OpenStream(Uri url) {
             Stream isp;
             if (url.IsFile) {
-                isp = new FileStream(Uri.UnescapeDataString(url.AbsolutePath), FileMode.Open, FileAccess.Read);
+                // do not replace first argument with Uri.UnescapeDataString(url.AbsolutePath) instead of url.LocalPath
+                // it breaks the recognition of network paths
+                isp = new FileStream(url.LocalPath, FileMode.Open, FileAccess.Read);     
             } else {
 #if !NETSTANDARD1_6
                 WebRequest req = WebRequest.Create(url);