Fixing parse

src/Discord.Net.Commands/CommandMatch.cs

@@ -16,8 +16,8 @@ namespace Discord.Commands
 
         public Task<PreconditionResult> CheckPreconditionsAsync(ICommandContext context, IDependencyMap map = null)
             => Command.CheckPreconditionsAsync(context, map);
-        public Task<ParseResult> ParseAsync(ICommandContext context, SearchResult searchResult, PreconditionResult? preconditionResult = null)
-            => Command.ParseAsync(context, Alias.Length, searchResult, preconditionResult);
+        public Task<ParseResult> ParseAsync(ICommandContext context, SearchResult searchResult)
+            => Command.ParseAsync(context, Alias.Length, searchResult);
         public Task<ExecuteResult> ExecuteAsync(ICommandContext context, IEnumerable<object> argList, IEnumerable<object> paramList, IDependencyMap map)
             => Command.ExecuteAsync(context, argList, paramList, map);
         public Task<ExecuteResult> ExecuteAsync(ICommandContext context, ParseResult parseResult, IDependencyMap map)

src/Discord.Net.Commands/CommandService.cs

@@ -245,6 +245,7 @@ namespace Discord.Commands
             if (!searchResult.IsSuccess)
                 return searchResult;
 
+            PreconditionResult? secondOption = null;
             var commands = searchResult.Commands;
             for (int i = commands.Count - 1; i >= 0; i--)
             {
@@ -253,11 +254,10 @@ namespace Discord.Commands
                 {
                     if (commands.Count == 1)
                         return preconditionResult;
-                    else
+                    else if (secondOption != null) //we already got our last hope, so we can skip
                         continue;
                 }
-
-                var parseResult = await commands[i].ParseAsync(context, searchResult, preconditionResult).ConfigureAwait(false);
+                var parseResult = await commands[i].ParseAsync(context, searchResult).ConfigureAwait(false);
                 if (!parseResult.IsSuccess)
                 {
                     if (parseResult.Error == CommandError.MultipleMatches)
@@ -272,19 +272,23 @@ namespace Discord.Commands
                                 break;
                         }
                     }
-
                     if (!parseResult.IsSuccess)
                     {
                         if (commands.Count == 1)
                             return parseResult;
-                        else
+                        else if (secondOption != null) //we already got our last hope, so we can skip
                             continue;
                     }
                 }
 
-                return await commands[i].ExecuteAsync(context, parseResult, dependencyMap).ConfigureAwait(false);
+                if (parseResult.IsSuccess && preconditionResult.IsSuccess)
+                    return await commands[i].ExecuteAsync(context, parseResult, dependencyMap).ConfigureAwait(false); // Perfect match and highest priority
+                else if (secondOption == null && parseResult.IsSuccess)
+                    secondOption = preconditionResult; // It's a parse match, not perfect, but the highest priority
             }
 
+            if (secondOption != null)
+                return secondOption;
             return SearchResult.FromError(CommandError.UnknownCommand, "This input does not match any overload.");
         }
     }

src/Discord.Net.Commands/Info/CommandInfo.cs

@@ -85,13 +85,13 @@ namespace Discord.Commands
             return PreconditionResult.FromSuccess();
         }
         
-        public async Task<ParseResult> ParseAsync(ICommandContext context, int startIndex, SearchResult searchResult, PreconditionResult? preconditionResult = null)
+        public async Task<ParseResult> ParseAsync(ICommandContext context, int startIndex, SearchResult searchResult)
         {
-            if (!searchResult.IsSuccess)
+            if (!searchResult.IsSuccess)                                            // I think this should be removed too. Same reason as below.
                 return ParseResult.FromError(searchResult);
-            if (preconditionResult != null && !preconditionResult.Value.IsSuccess)
-                return ParseResult.FromError(preconditionResult.Value);
-            
+            //if (preconditionResult != null && !preconditionResult.Value.IsSuccess)    Why? It could be our last hope and some preconditions removed it?
+            //    return ParseResult.FromError(preconditionResult.Value);               Parse should parse, not check if the preconditions are okay, this is ExecuteAsync's job.
+
             string input = searchResult.Text.Substring(startIndex);
             return await CommandParser.ParseArgs(this, context, input, 0).ConfigureAwait(false);
         }