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()

```

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)

{"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"}]}