prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  support@gittip.com still linked several places
  Should be support@gratipay.com, right? ;-)
  
  
  </issue>
  <code>
  [start of gratipay/exceptions.py]
  1 """
  2 This module contains exceptions shared across application code.
  3 """
  4 
  5 from __future__ import print_function, unicode_literals
  6 
  7 
  8 class ProblemChangingUsername(Exception):
  9     def __str__(self):
  10         return self.msg.format(self.args[0])
  11 
  12 class UsernameIsEmpty(ProblemChangingUsername):
  13     msg = "You need to provide a username!"
  14 
  15 class UsernameTooLong(ProblemChangingUsername):
  16     msg = "The username '{}' is too long."
  17 
  18 class UsernameContainsInvalidCharacters(ProblemChangingUsername):
  19     msg = "The username '{}' contains invalid characters."
  20 
  21 class UsernameIsRestricted(ProblemChangingUsername):
  22     msg = "The username '{}' is restricted."
  23 
  24 class UsernameAlreadyTaken(ProblemChangingUsername):
  25     msg = "The username '{}' is already taken."
  26 
  27 
  28 class ProblemChangingNumber(Exception):
  29     def __str__(self):
  30         return self.msg
  31 
  32 class HasBigTips(ProblemChangingNumber):
  33     msg = "You receive tips too large for an individual. Please contact support@gittip.com."
  34 
  35 
  36 class TooGreedy(Exception): pass
  37 class NoSelfTipping(Exception): pass
  38 class NoTippee(Exception): pass
  39 class BadAmount(Exception): pass
  40 class UserDoesntAcceptTips(Exception): pass
  41 
  42 class FailedToReserveUsername(Exception): pass
  43 
  44 class NegativeBalance(Exception):
  45     def __str__(self):
  46         return "Negative balance not allowed in this context."
  47 
  48 class NotWhitelisted(Exception): pass
  49 class NoBalancedCustomerHref(Exception): pass
  50
  [end of gratipay/exceptions.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/gratipay/exceptions.py b/gratipay/exceptions.py
  --- a/gratipay/exceptions.py
  +++ b/gratipay/exceptions.py
  @@ -30,7 +30,7 @@
           return self.msg
   
   class HasBigTips(ProblemChangingNumber):
  -    msg = "You receive tips too large for an individual. Please contact support@gittip.com."
  +    msg = "You receive tips too large for an individual. Please contact support@gratipay.com."
   
   
   class TooGreedy(Exception): pass
  
verification_info: {"golden_diff": "diff --git a/gratipay/exceptions.py b/gratipay/exceptions.py\n--- a/gratipay/exceptions.py\n+++ b/gratipay/exceptions.py\n@@ -30,7 +30,7 @@\n         return self.msg\n \n class HasBigTips(ProblemChangingNumber):\n-    msg = \"You receive tips too large for an individual. Please contact support@gittip.com.\"\n+    msg = \"You receive tips too large for an individual. Please contact support@gratipay.com.\"\n \n \n class TooGreedy(Exception): pass\n", "issue": "support@gittip.com still linked several places\nShould be support@gratipay.com, right? ;-)\n\n", "before_files": [{"content": "\"\"\"\nThis module contains exceptions shared across application code.\n\"\"\"\n\nfrom __future__ import print_function, unicode_literals\n\n\nclass ProblemChangingUsername(Exception):\n    def __str__(self):\n        return self.msg.format(self.args[0])\n\nclass UsernameIsEmpty(ProblemChangingUsername):\n    msg = \"You need to provide a username!\"\n\nclass UsernameTooLong(ProblemChangingUsername):\n    msg = \"The username '{}' is too long.\"\n\nclass UsernameContainsInvalidCharacters(ProblemChangingUsername):\n    msg = \"The username '{}' contains invalid characters.\"\n\nclass UsernameIsRestricted(ProblemChangingUsername):\n    msg = \"The username '{}' is restricted.\"\n\nclass UsernameAlreadyTaken(ProblemChangingUsername):\n    msg = \"The username '{}' is already taken.\"\n\n\nclass ProblemChangingNumber(Exception):\n    def __str__(self):\n        return self.msg\n\nclass HasBigTips(ProblemChangingNumber):\n    msg = \"You receive tips too large for an individual. Please contact support@gittip.com.\"\n\n\nclass TooGreedy(Exception): pass\nclass NoSelfTipping(Exception): pass\nclass NoTippee(Exception): pass\nclass BadAmount(Exception): pass\nclass UserDoesntAcceptTips(Exception): pass\n\nclass FailedToReserveUsername(Exception): pass\n\nclass NegativeBalance(Exception):\n    def __str__(self):\n        return \"Negative balance not allowed in this context.\"\n\nclass NotWhitelisted(Exception): pass\nclass NoBalancedCustomerHref(Exception): pass\n", "path": "gratipay/exceptions.py"}]}