From c6210f75cac186f644c899ea54f7ad9d3e0f733a Mon Sep 17 00:00:00 2001
From: Patrik Svensson <patrik@patriksvensson.se>
Date: Fri, 1 Jan 2021 22:54:44 +0100
Subject: [PATCH] Prevent endless loop in tokenization

Closes #198
---
 .../Internal/Parsing/CommandTreeTokenizer.cs  | 25 ++++++++++++-------
 .../Cli/Internal/TextBuffer.cs                |  6 +++++
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/src/Spectre.Console/Cli/Internal/Parsing/CommandTreeTokenizer.cs b/src/Spectre.Console/Cli/Internal/Parsing/CommandTreeTokenizer.cs
index a70a832..6495b94 100644
--- a/src/Spectre.Console/Cli/Internal/Parsing/CommandTreeTokenizer.cs
+++ b/src/Spectre.Console/Cli/Internal/Parsing/CommandTreeTokenizer.cs
@@ -63,16 +63,23 @@ namespace Spectre.Console.Cli.Internal
                 }
 
                 var character = reader.Peek();
-                if (!char.IsWhiteSpace(character))
+
+                // Eat whitespace
+                if (char.IsWhiteSpace(character))
                 {
-                    if (character == '-')
-                    {
-                        tokens.AddRange(ScanOptions(context, reader));
-                    }
-                    else
-                    {
-                        tokens.Add(ScanString(context, reader));
-                    }
+                    reader.Consume();
+                    continue;
+                }
+
+                if (character == '-')
+                {
+                    // Option
+                    tokens.AddRange(ScanOptions(context, reader));
+                }
+                else
+                {
+                    // Command or argument
+                    tokens.Add(ScanString(context, reader));
                 }
 
                 // Flush remaining tokens
diff --git a/src/Spectre.Console/Cli/Internal/TextBuffer.cs b/src/Spectre.Console/Cli/Internal/TextBuffer.cs
index 6237337..41ee2c2 100644
--- a/src/Spectre.Console/Cli/Internal/TextBuffer.cs
+++ b/src/Spectre.Console/Cli/Internal/TextBuffer.cs
@@ -51,6 +51,12 @@ namespace Spectre.Console.Cli.Internal
             return true;
         }
 
+        public void Consume()
+        {
+            EnsureNotAtEnd();
+            Read();
+        }
+
         public void Consume(char character)
         {
             EnsureNotAtEnd();