New error code for if you try to set a bad project name

build/Version.props

@@ -5,10 +5,10 @@
   <PropertyGroup>
     <TgsCoreVersion>6.7.0</TgsCoreVersion>
     <TgsConfigVersion>5.1.0</TgsConfigVersion>
-    <TgsApiVersion>10.5.0</TgsApiVersion>
+    <TgsApiVersion>10.6.0</TgsApiVersion>
     <TgsCommonLibraryVersion>7.0.0</TgsCommonLibraryVersion>
-    <TgsApiLibraryVersion>13.5.0</TgsApiLibraryVersion>
-    <TgsClientVersion>15.5.0</TgsClientVersion>
+    <TgsApiLibraryVersion>13.6.0</TgsApiLibraryVersion>
+    <TgsClientVersion>15.6.0</TgsClientVersion>
     <TgsDmapiVersion>7.1.3</TgsDmapiVersion>
     <TgsInteropVersion>5.9.0</TgsInteropVersion>
     <TgsHostWatchdogVersion>1.4.1</TgsHostWatchdogVersion>

src/Tgstation.Server.Api/Models/ErrorCode.cs

@@ -651,5 +651,11 @@ namespace Tgstation.Server.Api.Models
 		/// </summary>
 		[Description("Could not create dump as dotnet diagnostics threw an exception!")]
 		DotnetDiagnosticsFailure,
+
+		/// <summary>
+		/// The configured .dme could not be found.
+		/// </summary>
+		[Description("Could not load configured .dme due to it being outside the deployment directory! This should be a relative path.")]
+		DeploymentWrongDme,
 	}
 }

src/Tgstation.Server.Host/Components/Deployment/DreamMaker.cs

@@ -610,6 +610,9 @@ namespace Tgstation.Server.Host.Components.Deployment
 					var targetDmeExists = await ioManager.FileExists(targetDme, cancellationToken);
 					if (!targetDmeExists)
 						throw new JobException(ErrorCode.DeploymentMissingDme);
+
+					if (!await ioManager.PathIsChildOf(outputDirectory, targetDme, cancellationToken))
+						throw new JobException(ErrorCode.DeploymentWrongDme);
 				}
 
 				logger.LogDebug("Selected \"{dmeName}.dme\" for compilation!", job.DmeName);

tests/Tgstation.Server.Tests/Live/Instance/DeploymentTest.cs

@@ -1,4 +1,6 @@
 using System;
+using System.IO;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -200,6 +202,27 @@ namespace Tgstation.Server.Tests.Live.Instance
 			deployJob = await dreamMakerClient.Compile(cancellationToken);
 			await WaitForJob(deployJob, 40, true, ErrorCode.DeploymentMissingDme, cancellationToken);
 
+			// set to an absolute path that does exist
+			var tempFile = Path.GetTempFileName().Replace('\\', '/');
+			try
+			{
+				// for testing purposes, assume same drive for windows
+				var relativePath = $"../../{String.Join("/", instanceClient.Metadata.Path.Replace('\\', '/').Where(pathChar => pathChar == '/').Select(x => ".."))}{tempFile.Substring(tempFile.IndexOf('/'))}";
+				var dmePath = $"{tempFile}.dme";
+				File.Move(tempFile, dmePath);
+				tempFile = dmePath;
+				await dreamMakerClient.Update(new DreamMakerRequest
+				{
+					ProjectName = relativePath
+				}, cancellationToken);
+				deployJob = await dreamMakerClient.Compile(cancellationToken);
+				await WaitForJob(deployJob, 40, true, ErrorCode.DeploymentWrongDme, cancellationToken);
+			}
+			finally
+			{
+				File.Delete(tempFile);
+			}
+
 			// check that we can change the visibility
 
 			await vpTest;