prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  The smt combiner is raising IndexError exceptions in production.
  The CpuTopology combiner is throwing a large number of the exception IndexError('list index out of range',) in production.
  
  </issue>
  <code>
  [start of insights/combiners/smt.py]
  1 """
  2 Simultaneous Multithreading (SMT) combiner
  3 ==========================================
  4 
  5 Combiner for Simultaneous Multithreading (SMT). It uses the results of the following parsers:
  6 :class:`insights.parsers.smt.CpuCoreOnline`,
  7 :class:`insights.parsers.smt.CpuSiblings`.
  8 """
  9 
  10 from insights.core.plugins import combiner
  11 from insights.parsers.smt import CpuCoreOnline, CpuSiblings
  12 
  13 
  14 @combiner(CpuCoreOnline, CpuSiblings)
  15 class CpuTopology(object):
  16     """
  17     Class for collecting the online/siblings status for all CPU cores.
  18 
  19     Sample output of the ``CpuCoreOnline`` parser is::
  20 
  21         [[Core 0: Online], [Core 1: Online], [Core 2: Online], [Core 3: Online]]
  22 
  23     Sample output of the ``CpuSiblings`` parser is::
  24 
  25         [[Core 0 Siblings: [0, 2]], [Core 1 Siblings: [1, 3]], [Core 2 Siblings: [0, 2]], [Core 3 Siblings: [1, 3]]]
  26 
  27     Attributes:
  28         cores (list of dictionaries): List of all cores.
  29         all_solitary (bool): True, if hyperthreading is not used.
  30 
  31     Examples:
  32         >>> type(cpu_topology)
  33         <class 'insights.combiners.smt.CpuTopology'>
  34         >>> cpu_topology.cores == [{'online': True, 'siblings': [0, 2]}, {'online': True, 'siblings': [1, 3]}, {'online': True, 'siblings': [0, 2]}, {'online': True, 'siblings': [1, 3]}]
  35         True
  36         >>> cpu_topology.all_solitary
  37         False
  38     """
  39 
  40     def __init__(self, cpu_online, cpu_siblings):
  41         self.cores = []
  42 
  43         max_cpu_core_id = max([core.core_id for core in cpu_online])
  44         for n in range(max_cpu_core_id + 1):
  45             online = [core for core in cpu_online if core.core_id == n]
  46             online = online[0].on
  47             siblings = [sibling for sibling in cpu_siblings if sibling.core_id == n]
  48             if len(siblings) != 0:
  49                 siblings = siblings[0].siblings
  50 
  51             one_core = {"online": online, "siblings": siblings}
  52             self.cores.append(one_core)
  53 
  54         self.all_solitary = all([len(core["siblings"]) <= 1 for core in self.cores])
  55 
  56     def online(self, core_id):
  57         """
  58         Returns bool value obtained from "online" file for given core_id.
  59         """
  60         if core_id >= len(self.cores) or core_id < 0:
  61             return None
  62         return self.cores[core_id]["online"]
  63 
  64     def siblings(self, core_id):
  65         """
  66         Returns list of siblings for given core_id.
  67         """
  68         if core_id >= len(self.cores) or core_id < 0:
  69             return None
  70         return self.cores[core_id]["siblings"]
  71
  [end of insights/combiners/smt.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/insights/combiners/smt.py b/insights/combiners/smt.py
  --- a/insights/combiners/smt.py
  +++ b/insights/combiners/smt.py
  @@ -43,7 +43,13 @@
           max_cpu_core_id = max([core.core_id for core in cpu_online])
           for n in range(max_cpu_core_id + 1):
               online = [core for core in cpu_online if core.core_id == n]
  -            online = online[0].on
  +            # On some boxes cpu0 doesn't have the online file, since technically cpu0 will always
  +            # be online. So check if online returns anything before trying to access online[0].
  +            # If it returns nothing and n is 0 set online to True.
  +            if online:
  +                online = online[0].on
  +            elif not online and n == 0:
  +                online = True
               siblings = [sibling for sibling in cpu_siblings if sibling.core_id == n]
               if len(siblings) != 0:
                   siblings = siblings[0].siblings
  
verification_info: {"golden_diff": "diff --git a/insights/combiners/smt.py b/insights/combiners/smt.py\n--- a/insights/combiners/smt.py\n+++ b/insights/combiners/smt.py\n@@ -43,7 +43,13 @@\n         max_cpu_core_id = max([core.core_id for core in cpu_online])\n         for n in range(max_cpu_core_id + 1):\n             online = [core for core in cpu_online if core.core_id == n]\n-            online = online[0].on\n+            # On some boxes cpu0 doesn't have the online file, since technically cpu0 will always\n+            # be online. So check if online returns anything before trying to access online[0].\n+            # If it returns nothing and n is 0 set online to True.\n+            if online:\n+                online = online[0].on\n+            elif not online and n == 0:\n+                online = True\n             siblings = [sibling for sibling in cpu_siblings if sibling.core_id == n]\n             if len(siblings) != 0:\n                 siblings = siblings[0].siblings\n", "issue": "The smt combiner is raising IndexError exceptions in production.\nThe CpuTopology combiner is throwing a large number of the exception IndexError('list index out of range',) in production.\n", "before_files": [{"content": "\"\"\"\nSimultaneous Multithreading (SMT) combiner\n==========================================\n\nCombiner for Simultaneous Multithreading (SMT). It uses the results of the following parsers:\n:class:`insights.parsers.smt.CpuCoreOnline`,\n:class:`insights.parsers.smt.CpuSiblings`.\n\"\"\"\n\nfrom insights.core.plugins import combiner\nfrom insights.parsers.smt import CpuCoreOnline, CpuSiblings\n\n\n@combiner(CpuCoreOnline, CpuSiblings)\nclass CpuTopology(object):\n    \"\"\"\n    Class for collecting the online/siblings status for all CPU cores.\n\n    Sample output of the ``CpuCoreOnline`` parser is::\n\n        [[Core 0: Online], [Core 1: Online], [Core 2: Online], [Core 3: Online]]\n\n    Sample output of the ``CpuSiblings`` parser is::\n\n        [[Core 0 Siblings: [0, 2]], [Core 1 Siblings: [1, 3]], [Core 2 Siblings: [0, 2]], [Core 3 Siblings: [1, 3]]]\n\n    Attributes:\n        cores (list of dictionaries): List of all cores.\n        all_solitary (bool): True, if hyperthreading is not used.\n\n    Examples:\n        >>> type(cpu_topology)\n        <class 'insights.combiners.smt.CpuTopology'>\n        >>> cpu_topology.cores == [{'online': True, 'siblings': [0, 2]}, {'online': True, 'siblings': [1, 3]}, {'online': True, 'siblings': [0, 2]}, {'online': True, 'siblings': [1, 3]}]\n        True\n        >>> cpu_topology.all_solitary\n        False\n    \"\"\"\n\n    def __init__(self, cpu_online, cpu_siblings):\n        self.cores = []\n\n        max_cpu_core_id = max([core.core_id for core in cpu_online])\n        for n in range(max_cpu_core_id + 1):\n            online = [core for core in cpu_online if core.core_id == n]\n            online = online[0].on\n            siblings = [sibling for sibling in cpu_siblings if sibling.core_id == n]\n            if len(siblings) != 0:\n                siblings = siblings[0].siblings\n\n            one_core = {\"online\": online, \"siblings\": siblings}\n            self.cores.append(one_core)\n\n        self.all_solitary = all([len(core[\"siblings\"]) <= 1 for core in self.cores])\n\n    def online(self, core_id):\n        \"\"\"\n        Returns bool value obtained from \"online\" file for given core_id.\n        \"\"\"\n        if core_id >= len(self.cores) or core_id < 0:\n            return None\n        return self.cores[core_id][\"online\"]\n\n    def siblings(self, core_id):\n        \"\"\"\n        Returns list of siblings for given core_id.\n        \"\"\"\n        if core_id >= len(self.cores) or core_id < 0:\n            return None\n        return self.cores[core_id][\"siblings\"]\n", "path": "insights/combiners/smt.py"}]}