Inject invalid command for testing

Author: JimBobSquarePants

src/ImageSharp.Web/Middleware/ImageSharpMiddleware.cs

@@ -201,7 +201,7 @@ public async Task Invoke(HttpContext context)
                         break;
                     }
 
-                    ++index;
+                    index++;
                 }
             }
 
@@ -249,7 +249,7 @@ await this.ProcessRequestAsync(
         private void StripUnknownCommands(Dictionary<string, string> commands, int startAtIndex)
         {
             var keys = new List<string>(commands.Keys);
-            for (var index = startAtIndex; index < keys.Count; index++)
+            for (int index = startAtIndex; index < keys.Count; index++)
             {
                 string command = keys[index];
                 if (!this.knownCommands.Contains(command))

tests/ImageSharp.Web.Tests/Processing/PhysicalFileSystemCacheServerTests.cs

@@ -16,8 +16,8 @@ namespace SixLabors.ImageSharp.Web.Tests.Processing
     public class PhysicalFileSystemCacheServerTests : ServerTestBase<PhysicalFileSystemCacheTestServerFixture>
     {
         private const int Width = 20;
-        private static readonly string Command = "?width=" + Width + "&v=" + Guid.NewGuid().ToString();
-        private static readonly string Command2 = "?width=" + (Width + 1) + "&v=" + Guid.NewGuid().ToString();
+        private static readonly string Command = "?invalidcommand=qwerty&width=" + Width + "&v=" + Guid.NewGuid().ToString();
+        private static readonly string Command2 = "?invalidcommand=qwerty&width=" + (Width + 1) + "&v=" + Guid.NewGuid().ToString();
 
         public PhysicalFileSystemCacheServerTests(PhysicalFileSystemCacheTestServerFixture fixture)
             : base(fixture)