earlier check

Injector/Properties/VersionInfo.cs

@@ -12,4 +12,4 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("0.5.2.0")]
+[assembly: AssemblyVersion("0.5.2.1")]

Loader/GitHubClient.cs

@@ -57,19 +57,12 @@ public bool PublishRelease(CreateRelease create, params string[] assetsPaths)
 				if (!File.Exists(path))
 					throw new ArgumentException("File does not exist: " + path);
 
-			// check for extant release
-			Release[] releases = GetReleases();
-			if (releases == null)
+			string fail;
+			if (!CanCreateRelease(create.version, out fail))
 			{
-				Logger.WriteLine("Failed to download releases");
+				Logger.WriteLine(fail);
 				return false;
 			}
-			foreach (Release rel in releases)
-				if (rel.version.CompareTo(create.version) == 0)
-				{
-					Logger.WriteLine("Release exists: " + create.version);
-					return false;
-				}
 
 			// release needs to be draft while it is being created, in case of failure
 			bool draft = create.draft;
@@ -128,6 +121,31 @@ public bool PublishRelease(CreateRelease create, params string[] assetsPaths)
 			return true;
 		}
 
+		/// <summary>
+		/// Checks if a release with a specified version can be created.
+		/// </summary>
+		/// <param name="version">A version that might be in use.</param>
+		/// <param name="reason">In the event of failure, the reason for the failure.</param>
+		public bool CanCreateRelease(Version version, out string reason)
+		{
+			Release[] releases = GetReleases();
+			if (releases == null)
+			{
+				reason = "Failed to download releases";
+				return false;
+			}
+
+			foreach (Release release in releases)
+				if (release.version.CompareTo(version) == 0)
+				{
+					reason = "Release exists: " + version;
+					return false;
+				}
+
+			reason = null;
+			return true;
+		}
+
 		/// <summary>
 		/// Edit information about a release.
 		/// </summary>

Loader/ReleaseCreater.cs

@@ -45,6 +45,13 @@ public static void Publish(ModVersion modVersion, string directory, string oAuth
 				using (XmlDictionaryWriter writer = JsonReaderWriterFactory.CreateJsonWriter(new FileStream(releaseFile, FileMode.CreateNew), Encoding.UTF8, true, true))
 					serializer.WriteObject(writer, input);
 
+				string fail;
+				if (!client.CanCreateRelease(modVersion.version, out fail))
+				{
+					Console.WriteLine(fail);
+					return;
+				}
+
 				while (true)
 				{
 					Process edit = Process.Start(releaseFile);