prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  A little bug in Buffer class
  There is a litttle bug in pwnlib.tubes.Buffer class.The class method unget has a type error in  line 117.add a buffer and a list
  
  ```
  Traceback (most recent call last):
    File "<input>", line 1, in <module>
      a.unget(b)
    File "buffer.py", line 117, in unget
      self.data = data + self.data
  TypeError: unsupported operand type(s) for +: 'Buffer' and 'list'
  ```
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `pwnlib/tubes/buffer.py`
  Content:
  ```
  1 #!/usr/bin/env python2
  2 
  3 class Buffer(Exception):
  4     """
  5     List of strings with some helper routines.
  6 
  7     Example:
  8 
  9         >>> b = Buffer()
  10         >>> b.add("A" * 10)
  11         >>> b.add("B" * 10)
  12         >>> len(b)
  13         20
  14         >>> b.get(1)
  15         'A'
  16         >>> len(b)
  17         19
  18         >>> b.get(9999)
  19         'AAAAAAAAABBBBBBBBBB'
  20         >>> len(b)
  21         0
  22         >>> b.get(1)
  23         ''
  24 
  25     Implementation Details:
  26 
  27         Implemented as a list.  Strings are added onto the end.
  28         The ``0th`` item in the buffer is the oldest item, and
  29         will be received first.
  30     """
  31     def __init__(self):
  32         self.data = [] # Buffer
  33         self.size = 0  # Length
  34 
  35 
  36     def __len__(self):
  37         """
  38         >>> b = Buffer()
  39         >>> b.add('lol')
  40         >>> len(b) == 3
  41         True
  42         >>> b.add('foobar')
  43         >>> len(b) == 9
  44         True
  45         """
  46         return self.size
  47 
  48     def __nonzero__(self):
  49         return len(self) > 0
  50 
  51     def __contains__(self, x):
  52         """
  53         >>> b = Buffer()
  54         >>> b.add('asdf')
  55         >>> 'x' in b
  56         False
  57         >>> b.add('x')
  58         >>> 'x' in b
  59         True
  60         """
  61         for b in self.data:
  62             if x in b:
  63                 return True
  64         return False
  65 
  66     def index(self, x):
  67         """
  68         >>> b = Buffer()
  69         >>> b.add('asdf')
  70         >>> b.add('qwert')
  71         >>> b.index('t') == len(b) - 1
  72         True
  73         """
  74         sofar = 0
  75         for b in self.data:
  76             if x in b:
  77                 return sofar + b.index(x)
  78             sofar += len(b)
  79         raise IndexError()
  80 
  81     def add(self, data):
  82         """
  83         Adds data to the buffer.
  84 
  85         Arguments:
  86             data(str,Buffer): Data to add
  87         """
  88         # Fast path for ''
  89         if not data: return
  90 
  91         if isinstance(data, Buffer):
  92             self.size += data.size
  93             self.data += data.data
  94         else:
  95             self.size += len(data)
  96             self.data.append(data)
  97 
  98     def unget(self, data):
  99         """
  100         Places data at the front of the buffer.
  101 
  102         Arguments:
  103             data(str,Buffer): Data to place at the beginning of the buffer.
  104 
  105         Example:
  106 
  107             >>> b = Buffer()
  108             >>> b.add("hello")
  109             >>> b.add("world")
  110             >>> b.get(5)
  111             'hello'
  112             >>> b.unget("goodbye")
  113             >>> b.get()
  114             'goodbyeworld'
  115         """
  116         if isinstance(data, Buffer):
  117             self.data = data + self.data
  118             self.size += data.size
  119         else:
  120             self.data.insert(0, data)
  121             self.size += len(data)
  122 
  123     def get(self, want=float('inf')):
  124         """
  125         Retrieves bytes from the buffer.
  126 
  127         Arguments:
  128             want(int): Maximum number of bytes to fetch
  129 
  130         Returns:
  131             Data as string
  132 
  133         Example:
  134 
  135             >>> b = Buffer()
  136             >>> b.add('hello')
  137             >>> b.add('world')
  138             >>> b.get(1)
  139             'h'
  140             >>> b.get()
  141             'elloworld'
  142         """
  143         # Fast path, get all of the data
  144         if want >= self.size:
  145             data   = ''.join(self.data)
  146             self.size = 0
  147             self.data = []
  148             return data
  149 
  150         # Slow path, find the correct-index chunk
  151         have = 0
  152         i    = 0
  153         while want >= have:
  154             have += len(self.data[i])
  155             i    += 1
  156 
  157         # Join the chunks, evict from the buffer
  158         data   = ''.join(self.data[:i])
  159         self.data = self.data[i:]
  160 
  161         # If the last chunk puts us over the limit,
  162         # stick the extra back at the beginning.
  163         if have > want:
  164             extra = data[want:]
  165             data  = data[:want]
  166             self.data.insert(0, extra)
  167 
  168         # Size update
  169         self.size -= len(data)
  170 
  171         return data
  172
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/pwnlib/tubes/buffer.py b/pwnlib/tubes/buffer.py
  --- a/pwnlib/tubes/buffer.py
  +++ b/pwnlib/tubes/buffer.py
  @@ -114,7 +114,7 @@
               'goodbyeworld'
           """
           if isinstance(data, Buffer):
  -            self.data = data + self.data
  +            self.data = data.data + self.data
               self.size += data.size
           else:
               self.data.insert(0, data)
  
verification_info: {"golden_diff": "diff --git a/pwnlib/tubes/buffer.py b/pwnlib/tubes/buffer.py\n--- a/pwnlib/tubes/buffer.py\n+++ b/pwnlib/tubes/buffer.py\n@@ -114,7 +114,7 @@\n             'goodbyeworld'\n         \"\"\"\n         if isinstance(data, Buffer):\n-            self.data = data + self.data\n+            self.data = data.data + self.data\n             self.size += data.size\n         else:\n             self.data.insert(0, data)\n", "issue": "A little bug in Buffer class\nThere is a litttle bug in pwnlib.tubes.Buffer class.The class method unget has a type error in  line 117.add a buffer and a list\n\n```\nTraceback (most recent call last):\n  File \"<input>\", line 1, in <module>\n    a.unget(b)\n  File \"buffer.py\", line 117, in unget\n    self.data = data + self.data\nTypeError: unsupported operand type(s) for +: 'Buffer' and 'list'\n```\n\n", "before_files": [{"content": "#!/usr/bin/env python2\n\nclass Buffer(Exception):\n    \"\"\"\n    List of strings with some helper routines.\n\n    Example:\n\n        >>> b = Buffer()\n        >>> b.add(\"A\" * 10)\n        >>> b.add(\"B\" * 10)\n        >>> len(b)\n        20\n        >>> b.get(1)\n        'A'\n        >>> len(b)\n        19\n        >>> b.get(9999)\n        'AAAAAAAAABBBBBBBBBB'\n        >>> len(b)\n        0\n        >>> b.get(1)\n        ''\n\n    Implementation Details:\n\n        Implemented as a list.  Strings are added onto the end.\n        The ``0th`` item in the buffer is the oldest item, and\n        will be received first.\n    \"\"\"\n    def __init__(self):\n        self.data = [] # Buffer\n        self.size = 0  # Length\n\n\n    def __len__(self):\n        \"\"\"\n        >>> b = Buffer()\n        >>> b.add('lol')\n        >>> len(b) == 3\n        True\n        >>> b.add('foobar')\n        >>> len(b) == 9\n        True\n        \"\"\"\n        return self.size\n\n    def __nonzero__(self):\n        return len(self) > 0\n\n    def __contains__(self, x):\n        \"\"\"\n        >>> b = Buffer()\n        >>> b.add('asdf')\n        >>> 'x' in b\n        False\n        >>> b.add('x')\n        >>> 'x' in b\n        True\n        \"\"\"\n        for b in self.data:\n            if x in b:\n                return True\n        return False\n\n    def index(self, x):\n        \"\"\"\n        >>> b = Buffer()\n        >>> b.add('asdf')\n        >>> b.add('qwert')\n        >>> b.index('t') == len(b) - 1\n        True\n        \"\"\"\n        sofar = 0\n        for b in self.data:\n            if x in b:\n                return sofar + b.index(x)\n            sofar += len(b)\n        raise IndexError()\n\n    def add(self, data):\n        \"\"\"\n        Adds data to the buffer.\n\n        Arguments:\n            data(str,Buffer): Data to add\n        \"\"\"\n        # Fast path for ''\n        if not data: return\n\n        if isinstance(data, Buffer):\n            self.size += data.size\n            self.data += data.data\n        else:\n            self.size += len(data)\n            self.data.append(data)\n\n    def unget(self, data):\n        \"\"\"\n        Places data at the front of the buffer.\n\n        Arguments:\n            data(str,Buffer): Data to place at the beginning of the buffer.\n\n        Example:\n\n            >>> b = Buffer()\n            >>> b.add(\"hello\")\n            >>> b.add(\"world\")\n            >>> b.get(5)\n            'hello'\n            >>> b.unget(\"goodbye\")\n            >>> b.get()\n            'goodbyeworld'\n        \"\"\"\n        if isinstance(data, Buffer):\n            self.data = data + self.data\n            self.size += data.size\n        else:\n            self.data.insert(0, data)\n            self.size += len(data)\n\n    def get(self, want=float('inf')):\n        \"\"\"\n        Retrieves bytes from the buffer.\n\n        Arguments:\n            want(int): Maximum number of bytes to fetch\n\n        Returns:\n            Data as string\n\n        Example:\n\n            >>> b = Buffer()\n            >>> b.add('hello')\n            >>> b.add('world')\n            >>> b.get(1)\n            'h'\n            >>> b.get()\n            'elloworld'\n        \"\"\"\n        # Fast path, get all of the data\n        if want >= self.size:\n            data   = ''.join(self.data)\n            self.size = 0\n            self.data = []\n            return data\n\n        # Slow path, find the correct-index chunk\n        have = 0\n        i    = 0\n        while want >= have:\n            have += len(self.data[i])\n            i    += 1\n\n        # Join the chunks, evict from the buffer\n        data   = ''.join(self.data[:i])\n        self.data = self.data[i:]\n\n        # If the last chunk puts us over the limit,\n        # stick the extra back at the beginning.\n        if have > want:\n            extra = data[want:]\n            data  = data[:want]\n            self.data.insert(0, extra)\n\n        # Size update\n        self.size -= len(data)\n\n        return data\n", "path": "pwnlib/tubes/buffer.py"}], "after_files": [{"content": "#!/usr/bin/env python2\n\nclass Buffer(Exception):\n    \"\"\"\n    List of strings with some helper routines.\n\n    Example:\n\n        >>> b = Buffer()\n        >>> b.add(\"A\" * 10)\n        >>> b.add(\"B\" * 10)\n        >>> len(b)\n        20\n        >>> b.get(1)\n        'A'\n        >>> len(b)\n        19\n        >>> b.get(9999)\n        'AAAAAAAAABBBBBBBBBB'\n        >>> len(b)\n        0\n        >>> b.get(1)\n        ''\n\n    Implementation Details:\n\n        Implemented as a list.  Strings are added onto the end.\n        The ``0th`` item in the buffer is the oldest item, and\n        will be received first.\n    \"\"\"\n    def __init__(self):\n        self.data = [] # Buffer\n        self.size = 0  # Length\n\n\n    def __len__(self):\n        \"\"\"\n        >>> b = Buffer()\n        >>> b.add('lol')\n        >>> len(b) == 3\n        True\n        >>> b.add('foobar')\n        >>> len(b) == 9\n        True\n        \"\"\"\n        return self.size\n\n    def __nonzero__(self):\n        return len(self) > 0\n\n    def __contains__(self, x):\n        \"\"\"\n        >>> b = Buffer()\n        >>> b.add('asdf')\n        >>> 'x' in b\n        False\n        >>> b.add('x')\n        >>> 'x' in b\n        True\n        \"\"\"\n        for b in self.data:\n            if x in b:\n                return True\n        return False\n\n    def index(self, x):\n        \"\"\"\n        >>> b = Buffer()\n        >>> b.add('asdf')\n        >>> b.add('qwert')\n        >>> b.index('t') == len(b) - 1\n        True\n        \"\"\"\n        sofar = 0\n        for b in self.data:\n            if x in b:\n                return sofar + b.index(x)\n            sofar += len(b)\n        raise IndexError()\n\n    def add(self, data):\n        \"\"\"\n        Adds data to the buffer.\n\n        Arguments:\n            data(str,Buffer): Data to add\n        \"\"\"\n        # Fast path for ''\n        if not data: return\n\n        if isinstance(data, Buffer):\n            self.size += data.size\n            self.data += data.data\n        else:\n            self.size += len(data)\n            self.data.append(data)\n\n    def unget(self, data):\n        \"\"\"\n        Places data at the front of the buffer.\n\n        Arguments:\n            data(str,Buffer): Data to place at the beginning of the buffer.\n\n        Example:\n\n            >>> b = Buffer()\n            >>> b.add(\"hello\")\n            >>> b.add(\"world\")\n            >>> b.get(5)\n            'hello'\n            >>> b.unget(\"goodbye\")\n            >>> b.get()\n            'goodbyeworld'\n        \"\"\"\n        if isinstance(data, Buffer):\n            self.data = data.data + self.data\n            self.size += data.size\n        else:\n            self.data.insert(0, data)\n            self.size += len(data)\n\n    def get(self, want=float('inf')):\n        \"\"\"\n        Retrieves bytes from the buffer.\n\n        Arguments:\n            want(int): Maximum number of bytes to fetch\n\n        Returns:\n            Data as string\n\n        Example:\n\n            >>> b = Buffer()\n            >>> b.add('hello')\n            >>> b.add('world')\n            >>> b.get(1)\n            'h'\n            >>> b.get()\n            'elloworld'\n        \"\"\"\n        # Fast path, get all of the data\n        if want >= self.size:\n            data   = ''.join(self.data)\n            self.size = 0\n            self.data = []\n            return data\n\n        # Slow path, find the correct-index chunk\n        have = 0\n        i    = 0\n        while want >= have:\n            have += len(self.data[i])\n            i    += 1\n\n        # Join the chunks, evict from the buffer\n        data   = ''.join(self.data[:i])\n        self.data = self.data[i:]\n\n        # If the last chunk puts us over the limit,\n        # stick the extra back at the beginning.\n        if have > want:\n            extra = data[want:]\n            data  = data[:want]\n            self.data.insert(0, extra)\n\n        # Size update\n        self.size -= len(data)\n\n        return data\n", "path": "pwnlib/tubes/buffer.py"}]}