Fix infinite loops in BotTokenParser when looping through characters …

…and EOF is reached
ethanmoffat · Feb 4, 2022 · 48aad2d · 48aad2d
1 parent 8c696e4
commit 48aad2d
Showing 1 changed file with 8 additions and 4 deletions.
diff --git a/EOBot/Interpreter/BotTokenParser.cs b/EOBot/Interpreter/BotTokenParser.cs
@@ -75,7 +75,7 @@ public BotToken GetNextToken()
                     do
                     {
                         inputChar = Read();
-                    } while (inputChar != '\n');
+                    } while (inputChar != '\n' && !_inputStream.EndOfStream);
 
                     LineNumber++;
                     Column = 1;
@@ -86,7 +86,7 @@ public BotToken GetNextToken()
             if (char.IsLetter(inputChar))
             {
                 var identifier = inputChar.ToString();
-                while (char.IsLetterOrDigit(Peek()) || Peek() == '_')
+                while ((char.IsLetterOrDigit(Peek()) || Peek() == '_') && !_inputStream.EndOfStream)
                     identifier += Read();
 
                 var type = Keywords.Contains(identifier)
@@ -98,7 +98,7 @@ public BotToken GetNextToken()
             else if (char.IsDigit(inputChar))
             {
                 var number = inputChar.ToString();
-                while (char.IsDigit((char)_inputStream.Peek()))
+                while (char.IsDigit((char)_inputStream.Peek()) && !_inputStream.EndOfStream)
                     number += Read();
                 return Token(BotTokenType.Literal, number);
             }
@@ -117,8 +117,12 @@ public BotToken GetNextToken()
                     case '"':
                         {
                             var stringLiteral = string.Empty;
-                            while ((char)_inputStream.Peek() != '"')
+                            while ((char)_inputStream.Peek() != '"' && !_inputStream.EndOfStream)
                                 stringLiteral += Read();
+
+                            if (_inputStream.EndOfStream)
+                                return Token(BotTokenType.Error, string.Empty);
+
                             Read();
                             return Token(BotTokenType.Literal, stringLiteral);
                         }