BUG21530100: Fix reading option files

During iteration of a dictionary, deleting of a key from the
dictionary causes the following exception:

RuntimeError: dictionary changed size during iteration

This happens because `dict.keys` returns iterable views in
python 3 instead of copies like in python 2.

Using Python Dictionary Comprehension's fixes this issue.

Test has been added for regression.

Author: amitab

lib/mysql/connector/optionfiles.py

@@ -286,19 +286,19 @@ def get_groups(self, *args):
             args = self._options_dict.keys()
 
         options = {}
+        priority = {}
         for group in args:
             try:
-                for option, value in self._options_dict[group].items():
-                    if option not in options or options[option][1] <= value[1]:
-                        options[option] = value
+                for option, value in [(key, value,) for key, value in
+                                      self._options_dict[group].items() if
+                                      key != "__name__" and
+                                      not key.startswith("!")]:
+                    if option not in options or priority[option] <= value[1]:
+                        priority[option] = value[1]
+                        options[option] = value[0]
             except KeyError:
                 pass
 
-        for key in options.keys():
-            if key == '__name__' or key.startswith('!'):
-                del options[key]
-            else:
-                options[key] = options[key][0]
         return options
 
     def get_groups_as_dict_with_priority(self, *args): # pylint: disable=C0103
@@ -321,14 +321,13 @@ def get_groups_as_dict_with_priority(self, *args): # pylint: disable=C0103
         options = dict()
         for group in args:
             try:
-                options[group] = dict(self._options_dict[group])
+                options[group] = {key: value for key, value in
+                                  self._options_dict[group].items() if
+                                  key != "__name__" and
+                                  not key.startswith("!")}
             except KeyError:
                 pass
 
-        for group in options.keys():
-            for key in options[group].keys():
-                if key == '__name__' or key.startswith('!'):
-                    del options[group][key]
         return options
 
     def get_groups_as_dict(self, *args):
@@ -347,14 +346,11 @@ def get_groups_as_dict(self, *args):
         options = dict()
         for group in args:
             try:
-                options[group] = dict(self._options_dict[group])
+                options[group] = {key: value[0] for key, value in
+                                  self._options_dict[group].items() if
+                                  key != "__name__" and
+                                  not key.startswith("!")}
             except KeyError:
                 pass
 
-        for group in options.keys():
-            for key in options[group].keys():
-                if key == '__name__' or key.startswith('!'):
-                    del options[group][key]
-                else:
-                    options[group][key] = options[group][key][0]
         return options

tests/test_bugs.py

@@ -3119,6 +3119,46 @@ def test_unsupported_arguments(self):
         self.assertEqual(exp, new_config)
 
 
+class BugOra21530100(tests.MySQLConnectorTests):
+    """BUG#21530100: CONNECT FAILS WHEN USING MULTIPLE OPTION_GROUPS WITH
+       PYTHON 3.3
+    """
+    def test_option_files_with_option_groups(self):
+        temp_cnf_file = os.path.join(os.getcwd(), 'temp.cnf')
+        temp_include_file = os.path.join(os.getcwd(), 'include.cnf')
+
+        try:
+            cnf_file = open(temp_cnf_file, "w+")
+            include_file = open(temp_include_file, "w+")
+
+            config = tests.get_mysql_config()
+
+            cnf = "[group32]\n"
+            cnf += '\n'.join(['{0} = {1}'.format(key, value)
+                             for key, value in config.items()])
+
+            cnf += "\n[group31]\n"
+            cnf += "!include {0}\n".format(temp_include_file)
+
+            include_cnf = "[group41]\n"
+            include_cnf += "charset=utf8\n"
+
+            cnf_file.write(cnf)
+            include_file.write(include_cnf)
+
+            cnf_file.close()
+            include_file.close()
+
+            conn = mysql.connector.connect(option_files=temp_cnf_file,
+                option_groups=['group31','group32','group41'])
+        except Exception as exc:
+            self.fail("Connection failed with option_files argument: {0}"
+                      "".format(exc))
+        finally:
+            os.remove(temp_cnf_file)
+            os.remove(temp_include_file)
+
+
 class BugOra19481761(tests.MySQLConnectorTests):
     """BUG#19481761: OPTION_FILES + !INCLUDE FAILS WITH TRAILING NEWLINE
     """