Amend #828 to introduce a new TryParse method

instead of changing the behavior of an existing one.

Per discussion with @bording and @ig-sinicyn in #827.

Author: michaelklishin

projects/RabbitMQ.Client/client/api/PublicationAddress.cs

@@ -106,14 +106,6 @@ public PublicationAddress(string exchangeType, string exchangeName, string routi
         /// </summary>
         public static PublicationAddress Parse(string uriLikeString)
         {
-            // Callers such as IBasicProperties.ReplyToAddress
-            // expect null result for invalid input.
-            // The regex.Match() throws on null arguments so we perform explicit check here
-            if (uriLikeString == null)
-            {
-                return null;
-            }
-
             Match match = PSEUDO_URI_PARSER.Match(uriLikeString);
             if (match.Success)
             {
@@ -124,6 +116,22 @@ public static PublicationAddress Parse(string uriLikeString)
             return null;
         }
 
+        public static PublicationAddress TryParse(string uriLikeString) {
+            // Callers such as IBasicProperties.ReplyToAddress
+            // expect null result for invalid input.
+            // The regex.Match() throws on null arguments so we perform explicit check here
+            if (uriLikeString == null)
+            {
+                return null;
+            } else {
+                try {
+                    return Parse(uriLikeString);
+                } catch {
+                    return null;
+                }
+            }
+        }
+
         /// <summary>
         /// Reconstruct the "uri" from its constituents.
         /// </summary>

projects/RabbitMQ.Client/client/impl/BasicProperties.cs

@@ -115,7 +115,7 @@ public bool Persistent
         /// </summary>
         public PublicationAddress ReplyToAddress
         {
-            get { return PublicationAddress.Parse(ReplyTo); }
+            get { return PublicationAddress.TryParse(ReplyTo); }
             set { ReplyTo = value.ToString(); }
         }
 

projects/Unit/TestPublicationAddress.cs

@@ -57,10 +57,23 @@ public void TestParseOk()
         }
 
         [Test]
-        public void TestParseFail()
+        public void TestParseFailWithANE()
         {
-            Assert.IsNull(PublicationAddress.Parse(null));
-            Assert.IsNull(PublicationAddress.Parse("not a valid uri"));
+            Assert.That(()=> PublicationAddress.Parse(null), Throws.ArgumentNullException);
+        }
+
+        [Test]
+        public void TestParseFailWithUnparseableInput()
+        {
+            Assert.IsNull(PublicationAddress.Parse("not a valid URI"));
+        }
+
+        [Test]
+        public void TestTryParseFail()
+        {
+            Assert.IsNull(PublicationAddress.TryParse(null));
+            Assert.IsNull(PublicationAddress.TryParse("not a valid URI"));
+            Assert.IsNull(PublicationAddress.TryParse("}}}}}}}}"));
         }
 
         [Test]