prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  tagger analyzer not functiong properly 
  **Describe the bug**
  After upgrade TimeSketch to version: 20210602 the tagger analyzer is not functioning with custom tags
  
  **To Reproduce**
  Steps to reproduce the behavior:
  1. Import plaso file with evtx data 
  2. Add the following tagging rule to tags.yaml
  ```yaml
  logon_tagger:  
    query_string: 'data_type: "windows:evtx:record" AND source_name: "Microsoft-Windows-Security-Auditing" AND event_identifier: 4688'
    tags: ['logon']
    save_search: true
    search_name: 'logon'
  ```
  3. run tagger analyzer
  4. See error
  
  **Expected behavior**
  The tagger analyzer to run correctly as in previous versions.
  
  **Desktop (please complete the following information):**
  -OS:Ubuntu 20.04.2 LTS
  -Browser : Firefox
  -Version: 86.0
  
  **Additional context**
  The following exception is thrown once the tagger analyzer is ran:
  ```
  Traceback (most recent call last): File "/usr/local/lib/python3.8/dist-packages/timesketch/lib/analyzers/interface.py", line 995, in run_wrapper result = self.run() File "/usr/local/lib/python3.8/dist-packages/timesketch/lib/analyzers/tagger.py", line 48, in run tag_result = self.tagger(name, tag_config) File "/usr/local/lib/python3.8/dist-packages/timesketch/lib/analyzers/tagger.py", line 100, in tagger if expression: UnboundLocalError: local variable 'expression' referenced before assignment
  ``` 
  
  
  </issue>
  <code>
  [start of timesketch/lib/analyzers/tagger.py]
  1 """Analyzer plugin for tagging."""
  2 import logging
  3 
  4 from timesketch.lib import emojis
  5 from timesketch.lib.analyzers import interface
  6 from timesketch.lib.analyzers import manager
  7 from timesketch.lib.analyzers import utils
  8 
  9 
  10 logger = logging.getLogger('timesketch.analyzers.tagger')
  11 
  12 
  13 class TaggerSketchPlugin(interface.BaseAnalyzer):
  14     """Analyzer for tagging events."""
  15 
  16     NAME = 'tagger'
  17     DISPLAY_NAME = 'Tagger'
  18     DESCRIPTION = 'Tag events based on pre-defined rules'
  19 
  20     CONFIG_FILE = 'tags.yaml'
  21 
  22     def __init__(self, index_name, sketch_id, timeline_id=None, config=None):
  23         """Initialize The Sketch Analyzer.
  24 
  25         Args:
  26             index_name: Elasticsearch index name
  27             sketch_id: Sketch ID
  28             timeline_id: The ID of the timeline.
  29             config: Optional dict that contains the configuration for the
  30                 analyzer. If not provided, the default YAML file will be used.
  31         """
  32         self.index_name = index_name
  33         self._config = config
  34         super().__init__(index_name, sketch_id, timeline_id=timeline_id)
  35 
  36     def run(self):
  37         """Entry point for the analyzer.
  38 
  39         Returns:
  40             String with summary of the analyzer result.
  41         """
  42         config = self._config or interface.get_yaml_config(self.CONFIG_FILE)
  43         if not config:
  44             return 'Unable to parse the config file.'
  45 
  46         tag_results = []
  47         for name, tag_config in iter(config.items()):
  48             tag_result = self.tagger(name, tag_config)
  49             if tag_result and not tag_result.startswith('0 events tagged'):
  50                 tag_results.append(tag_result)
  51 
  52         if tag_results:
  53             return ', '.join(tag_results)
  54         return 'No tags applied'
  55 
  56     def tagger(self, name, config):
  57         """Tag and add emojis to events.
  58 
  59         Args:
  60             name: String with the name describing what will be tagged.
  61             config: A dict that contains the configuration See data/tags.yaml
  62                 for fields and documentation of what needs to be defined.
  63 
  64         Returns:
  65             String with summary of the analyzer result.
  66         """
  67         query = config.get('query_string')
  68         query_dsl = config.get('query_dsl')
  69         save_search = config.get('save_search', False)
  70         # For legacy reasons to support both save_search and
  71         # create_view parameters.
  72         if not save_search:
  73             save_search = config.get('create_view', False)
  74 
  75         search_name = config.get('search_name', None)
  76         # For legacy reasons to support both search_name and view_name.
  77         if search_name is None:
  78             search_name = config.get('view_name', name)
  79 
  80         tags = config.get('tags', [])
  81         emoji_names = config.get('emojis', [])
  82         emojis_to_add = [emojis.get_emoji(x) for x in emoji_names]
  83 
  84         expression_string = config.get('regular_expression', '')
  85         attributes = None
  86         if expression_string:
  87             expression = utils.compile_regular_expression(
  88                 expression_string=expression_string,
  89                 expression_flags=config.get('re_flags'))
  90 
  91             attribute = config.get('re_attribute')
  92             if attribute:
  93                 attributes = [attribute]
  94 
  95         event_counter = 0
  96         events = self.event_stream(
  97             query_string=query, query_dsl=query_dsl, return_fields=attributes)
  98 
  99         for event in events:
  100             if expression:
  101                 value = event.source.get(attributes[0])
  102                 if value:
  103                     result = expression.findall(value)
  104                     if not result:
  105                         # Skip counting this tag since the regular expression
  106                         # didn't find anything.
  107                         continue
  108 
  109             event_counter += 1
  110             event.add_tags(tags)
  111             event.add_emojis(emojis_to_add)
  112 
  113             # Commit the event to the datastore.
  114             event.commit()
  115 
  116         if save_search and event_counter:
  117             self.sketch.add_view(
  118                 search_name, self.NAME, query_string=query, query_dsl=query_dsl)
  119 
  120         return '{0:d} events tagged for [{1:s}]'.format(event_counter, name)
  121 
  122 
  123 manager.AnalysisManager.register_analyzer(TaggerSketchPlugin)
  124
  [end of timesketch/lib/analyzers/tagger.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/timesketch/lib/analyzers/tagger.py b/timesketch/lib/analyzers/tagger.py
  --- a/timesketch/lib/analyzers/tagger.py
  +++ b/timesketch/lib/analyzers/tagger.py
  @@ -83,6 +83,7 @@
   
           expression_string = config.get('regular_expression', '')
           attributes = None
  +        expression = None
           if expression_string:
               expression = utils.compile_regular_expression(
                   expression_string=expression_string,
  
verification_info: {"golden_diff": "diff --git a/timesketch/lib/analyzers/tagger.py b/timesketch/lib/analyzers/tagger.py\n--- a/timesketch/lib/analyzers/tagger.py\n+++ b/timesketch/lib/analyzers/tagger.py\n@@ -83,6 +83,7 @@\n \n         expression_string = config.get('regular_expression', '')\n         attributes = None\n+        expression = None\n         if expression_string:\n             expression = utils.compile_regular_expression(\n                 expression_string=expression_string,\n", "issue": "tagger analyzer not functiong properly \n**Describe the bug**\r\nAfter upgrade TimeSketch to version: 20210602 the tagger analyzer is not functioning with custom tags\r\n\r\n**To Reproduce**\r\nSteps to reproduce the behavior:\r\n1. Import plaso file with evtx data \r\n2. Add the following tagging rule to tags.yaml\r\n```yaml\r\nlogon_tagger:  \r\n  query_string: 'data_type: \"windows:evtx:record\" AND source_name: \"Microsoft-Windows-Security-Auditing\" AND event_identifier: 4688'\r\n  tags: ['logon']\r\n  save_search: true\r\n  search_name: 'logon'\r\n```\r\n3. run tagger analyzer\r\n4. See error\r\n\r\n**Expected behavior**\r\nThe tagger analyzer to run correctly as in previous versions.\r\n\r\n**Desktop (please complete the following information):**\r\n-OS:Ubuntu 20.04.2 LTS\r\n-Browser : Firefox\r\n-Version: 86.0\r\n\r\n**Additional context**\r\nThe following exception is thrown once the tagger analyzer is ran:\r\n```\r\nTraceback (most recent call last): File \"/usr/local/lib/python3.8/dist-packages/timesketch/lib/analyzers/interface.py\", line 995, in run_wrapper result = self.run() File \"/usr/local/lib/python3.8/dist-packages/timesketch/lib/analyzers/tagger.py\", line 48, in run tag_result = self.tagger(name, tag_config) File \"/usr/local/lib/python3.8/dist-packages/timesketch/lib/analyzers/tagger.py\", line 100, in tagger if expression: UnboundLocalError: local variable 'expression' referenced before assignment\r\n``` \r\n\n", "before_files": [{"content": "\"\"\"Analyzer plugin for tagging.\"\"\"\nimport logging\n\nfrom timesketch.lib import emojis\nfrom timesketch.lib.analyzers import interface\nfrom timesketch.lib.analyzers import manager\nfrom timesketch.lib.analyzers import utils\n\n\nlogger = logging.getLogger('timesketch.analyzers.tagger')\n\n\nclass TaggerSketchPlugin(interface.BaseAnalyzer):\n    \"\"\"Analyzer for tagging events.\"\"\"\n\n    NAME = 'tagger'\n    DISPLAY_NAME = 'Tagger'\n    DESCRIPTION = 'Tag events based on pre-defined rules'\n\n    CONFIG_FILE = 'tags.yaml'\n\n    def __init__(self, index_name, sketch_id, timeline_id=None, config=None):\n        \"\"\"Initialize The Sketch Analyzer.\n\n        Args:\n            index_name: Elasticsearch index name\n            sketch_id: Sketch ID\n            timeline_id: The ID of the timeline.\n            config: Optional dict that contains the configuration for the\n                analyzer. If not provided, the default YAML file will be used.\n        \"\"\"\n        self.index_name = index_name\n        self._config = config\n        super().__init__(index_name, sketch_id, timeline_id=timeline_id)\n\n    def run(self):\n        \"\"\"Entry point for the analyzer.\n\n        Returns:\n            String with summary of the analyzer result.\n        \"\"\"\n        config = self._config or interface.get_yaml_config(self.CONFIG_FILE)\n        if not config:\n            return 'Unable to parse the config file.'\n\n        tag_results = []\n        for name, tag_config in iter(config.items()):\n            tag_result = self.tagger(name, tag_config)\n            if tag_result and not tag_result.startswith('0 events tagged'):\n                tag_results.append(tag_result)\n\n        if tag_results:\n            return ', '.join(tag_results)\n        return 'No tags applied'\n\n    def tagger(self, name, config):\n        \"\"\"Tag and add emojis to events.\n\n        Args:\n            name: String with the name describing what will be tagged.\n            config: A dict that contains the configuration See data/tags.yaml\n                for fields and documentation of what needs to be defined.\n\n        Returns:\n            String with summary of the analyzer result.\n        \"\"\"\n        query = config.get('query_string')\n        query_dsl = config.get('query_dsl')\n        save_search = config.get('save_search', False)\n        # For legacy reasons to support both save_search and\n        # create_view parameters.\n        if not save_search:\n            save_search = config.get('create_view', False)\n\n        search_name = config.get('search_name', None)\n        # For legacy reasons to support both search_name and view_name.\n        if search_name is None:\n            search_name = config.get('view_name', name)\n\n        tags = config.get('tags', [])\n        emoji_names = config.get('emojis', [])\n        emojis_to_add = [emojis.get_emoji(x) for x in emoji_names]\n\n        expression_string = config.get('regular_expression', '')\n        attributes = None\n        if expression_string:\n            expression = utils.compile_regular_expression(\n                expression_string=expression_string,\n                expression_flags=config.get('re_flags'))\n\n            attribute = config.get('re_attribute')\n            if attribute:\n                attributes = [attribute]\n\n        event_counter = 0\n        events = self.event_stream(\n            query_string=query, query_dsl=query_dsl, return_fields=attributes)\n\n        for event in events:\n            if expression:\n                value = event.source.get(attributes[0])\n                if value:\n                    result = expression.findall(value)\n                    if not result:\n                        # Skip counting this tag since the regular expression\n                        # didn't find anything.\n                        continue\n\n            event_counter += 1\n            event.add_tags(tags)\n            event.add_emojis(emojis_to_add)\n\n            # Commit the event to the datastore.\n            event.commit()\n\n        if save_search and event_counter:\n            self.sketch.add_view(\n                search_name, self.NAME, query_string=query, query_dsl=query_dsl)\n\n        return '{0:d} events tagged for [{1:s}]'.format(event_counter, name)\n\n\nmanager.AnalysisManager.register_analyzer(TaggerSketchPlugin)\n", "path": "timesketch/lib/analyzers/tagger.py"}]}