Merge branch 'master' of github.com:ASKBOT/askbot-devel

16 files changed, 505 insertions, 244 deletions

diff --git a/askbot/__init__.py b/askbot/__init__.py
index 859b2695..8e4f20ab 100644
--- a/askbot/__init__.py
+++ b/askbot/__init__.py
@@ -5,9 +5,6 @@ Functions in the askbot module perform various
 basic actions on behalf of the forum application
 """
 import os
-import smtplib
-import sys
-import logging
 
 VERSION = (0, 7, 43)
 
@@ -43,17 +40,19 @@ try:
     from askbot.deployment.assertions import assert_package_compatibility
     assert_package_compatibility()
     patches.patch_django()
-    patches.patch_coffin()#must go after django
+    patches.patch_coffin()  # must go after django
 except ImportError:
     pass
 
+
 def get_install_directory():
     """returns path to directory
-    where code of the askbot django application 
+    where code of the askbot django application
     is installed
     """
     return os.path.dirname(__file__)
 
+
 def get_path_to(relative_path):
     """returns absolute path to a file
     relative to ``askbot`` directory
@@ -72,10 +71,11 @@ def get_version():
     """
     return '.'.join([str(subversion) for subversion in VERSION])
 
+
 def get_database_engine_name():
     """returns name of the database engine,
     independently of the version of django
-    - for django >=1.2 looks into ``settings.DATABASES['default']``, 
+    - for django >=1.2 looks into ``settings.DATABASES['default']``,
     (i.e. assumes that askbot uses database named 'default')
     , and for django 1.1 and below returns settings.DATABASE_ENGINE
     """
diff --git a/askbot/conf/forum_data_rules.py b/askbot/conf/forum_data_rules.py
index a26aa4b3..b7077a15 100644
--- a/askbot/conf/forum_data_rules.py
+++ b/askbot/conf/forum_data_rules.py
@@ -122,6 +122,17 @@ settings.register(
 settings.register(
     livesettings.BooleanValue(
         FORUM_DATA_RULES,
+        'LIMIT_ONE_ANSWER_PER_USER',
+        default = True,
+        description = _(
+            'Limit one answer per question per user'
+        )
+    )
+)
+
+settings.register(
+    livesettings.BooleanValue(
+        FORUM_DATA_RULES,
         'TAGS_ARE_REQUIRED',
         description = _('Are tags required?'),
         default = False,
diff --git a/askbot/doc/source/changelog.rst b/askbot/doc/source/changelog.rst
index 00918e76..c0540be9 100644
--- a/askbot/doc/source/changelog.rst
+++ b/askbot/doc/source/changelog.rst
@@ -3,6 +3,8 @@ Changes in Askbot
 
 Development version
 -------------------
+* Added optional support for unicode slugs (Evgeny)
+* Optionally allow limiting one answer per question per person (Evgeny)
 * Added management command `build_livesettings_cache` (Adolfo)
 * Welcome email for the case when replying by email is enabled (Evgeny)
 * Detection of email signature based on the response to the welcome email (Evgeny)
diff --git a/askbot/doc/source/settings.rst b/askbot/doc/source/settings.rst
new file mode 100644
index 00000000..d07e697b
--- /dev/null
+++ b/askbot/doc/source/settings.rst
@@ -0,0 +1,14 @@
+=================================
+Settings for ``settings.py`` file
+=================================
+
+* ``ALLOW_UNICODE_SLUGS`` - if ``True``, slugs will use unicode, default - ``False``
+
+There are more settings that are not documented yet,
+but most are described in the ``settings.py`` template:
+
+    askbot/setup_templates/settings.py.mustache
+
+TODO: describe all of them here.
+
+
diff --git a/askbot/exceptions.py b/askbot/exceptions.py
index d2d5ddf0..12802e7e 100644
--- a/askbot/exceptions.py
+++ b/askbot/exceptions.py
@@ -19,6 +19,11 @@ class InsufficientReputation(exceptions.PermissionDenied):
     """
     pass
 
+class AnswerAlreadyGiven(exceptions.PermissionDenied):
+    """Raised when user attempts to post a second answer
+    to the same question"""
+    pass
+
 class DuplicateCommand(exceptions.PermissionDenied):
     """exception class to indicate that something
     that can happen only once was attempted for the second time
diff --git a/askbot/forms.py b/askbot/forms.py
index 81382a2c..1188ed59 100644
--- a/askbot/forms.py
+++ b/askbot/forms.py
@@ -1,3 +1,5 @@
+"""Forms, custom form fields and related utility functions
+used in AskBot"""
 import re
 from django import forms
 from askbot import const
@@ -5,7 +7,6 @@ from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import ungettext_lazy, string_concat
 from django.utils.text import get_text_list
 from django.contrib.auth.models import User
-from django.contrib.contenttypes.models import ContentType
 from django_countries import countries
 from askbot.utils.forms import NextUrlField, UserNameField
 from askbot.mail import extract_first_email_address
@@ -13,6 +14,7 @@ from recaptcha_works.fields import RecaptchaField
 from askbot.conf import settings as askbot_settings
 import logging
 
+
 def cleanup_dict(dictionary, key, empty_value):
     """deletes key from dictionary if it exists
     and the corresponding value equals the empty_value
@@ -20,13 +22,27 @@ def cleanup_dict(dictionary, key, empty_value):
     if key in dictionary and dictionary[key] == empty_value:
         del dictionary[key]
 
+
 def format_form_errors(form):
+    """Formats form errors in HTML
+    if there is only one error - returns a plain string
+    if more than one, returns an unordered list of errors
+    in HTML format.
+    If there are no errors, returns empty string
+    """
     if form.errors:
         errors = form.errors.values()
         if len(errors) == 1:
             return errors[0]
         else:
-            return 'hahahahah'
+            result = '<ul>'
+            for error in errors:
+                result += '<li>%s</li>' % error
+            result += '</ul>'
+            return result
+    else:
+        return ''
+
 
 def clean_marked_tagnames(tagnames):
     """return two strings - one containing tagnames
@@ -35,7 +51,7 @@ def clean_marked_tagnames(tagnames):
     wildcard tags are those that have an asterisk at the end
     the function does not verify that the tag names are valid
     """
-    if askbot_settings.USE_WILDCARD_TAGS == False:
+    if askbot_settings.USE_WILDCARD_TAGS is False:
         return tagnames, list()
 
     pure_tags = list()
@@ -53,7 +69,8 @@ def clean_marked_tagnames(tagnames):
 
     return pure_tags, wildcards
 
-def filter_choices(remove_choices = None, from_choices = None):
+
+def filter_choices(remove_choices=None, from_choices=None):
     """a utility function that will remove choice tuples
     usable for the forms.ChoicesField from
     ``from_choices``, the removed ones will be those given
@@ -73,12 +90,47 @@ def filter_choices(remove_choices = None, from_choices = None):
             if choice == choice_to_test[0]:
                 remove = True
                 break
-        if remove == False:
-            filtered_choices += ( choice_to_test, )
+        if remove is False:
+            filtered_choices += (choice_to_test, )
 
     return filtered_choices
 
-COUNTRY_CHOICES = (('unknown',_('select country')),) + countries.COUNTRIES
+
+def need_mandatory_tags():
+    """true, if list of mandatory tags is not empty"""
+    from askbot import models
+    return (
+        askbot_settings.TAGS_ARE_REQUIRED
+        and len(models.tag.get_mandatory_tags()) > 0
+    )
+
+
+def mandatory_tag_missing_in_list(tag_strings):
+    """true, if mandatory tag is not present in the list
+    of ``tag_strings``"""
+    from askbot import models
+    mandatory_tags = models.tag.get_mandatory_tags()
+    for mandatory_tag in mandatory_tags:
+        for tag_string in tag_strings:
+            if tag_strings_match(tag_string, mandatory_tag):
+                return False
+    return True
+
+
+def tag_strings_match(tag_string, mandatory_tag):
+    """true if tag string matches the mandatory tag,
+    the comparison is not symmetric if tag_string ends with a
+    wildcard (asterisk)
+    """
+    if mandatory_tag.endswith('*'):
+        return tag_string.startswith(mandatory_tag[:-1])
+    else:
+        return tag_string == mandatory_tag
+
+
+
+COUNTRY_CHOICES = (('unknown', _('select country')),) + countries.COUNTRIES
+
 
 class CountryField(forms.ChoiceField):
     """this is better placed into the django_coutries app"""
@@ -100,10 +152,13 @@ class CountryField(forms.ChoiceField):
             return None
         return value
 
+
 class CountedWordsField(forms.CharField):
-    
+    """a field where a number of words is expected
+    to be in a certain range"""
+
     def __init__(
-        self, min_words = 0, max_words = 9999, field_name = None,
+        self, min_words=0, max_words=9999, field_name=None,
         *args, **kwargs
     ):
         self.min_words = min_words
@@ -144,28 +199,38 @@ class CountedWordsField(forms.CharField):
 
 
 class DomainNameField(forms.CharField):
+    """Field for Internet Domain Names
+    todo: maybe there is a standard field for this?
+    """
     def clean(self, value):
         #find a better regex, taking into account tlds
         domain_re = re.compile(r'[a-zA-Z\d]+(\.[a-zA-Z\d]+)+')
         if domain_re.match(value):
             return value
         else:
-            raise forms.ValidationError('%s is not a valid domain name' % value)
+            raise forms.ValidationError(
+                '%s is not a valid domain name' % value
+            )
 
 
 class TitleField(forms.CharField):
+    """Fild receiving question title"""
     def __init__(self, *args, **kwargs):
         super(TitleField, self).__init__(*args, **kwargs)
         self.required = True
         self.widget = forms.TextInput(
-                                attrs={'size' : 70, 'autocomplete' : 'off'}
-                            )
+                            attrs={'size': 70, 'autocomplete': 'off'}
+                        )
         self.max_length = 255
-        self.label  = _('title')
-        self.help_text = _('please enter a descriptive title for your question')
+        self.label = _('title')
+        self.help_text = _(
+            'please enter a descriptive title for your question'
+        )
         self.initial = ''
 
     def clean(self, value):
+        """cleans the field for minimum and maximum length
+        also is supposed to work for unicode non-ascii characters"""
         if value is None:
             value = ''
         if len(value) < askbot_settings.MIN_TITLE_LENGTH:
@@ -192,21 +257,22 @@ class TitleField(forms.CharField):
                 ) % self.max_length
             )
 
-        return value.strip() # TODO: test me
+        return value.strip()  # TODO: test me
+
 
 class EditorField(forms.CharField):
-    """EditorField is subclassed by the 
+    """EditorField is subclassed by the
     :class:`QuestionEditorField` and :class:`AnswerEditorField`
     """
     length_error_template_singular = 'post content must be > %d character',
     length_error_template_plural = 'post content must be > %d characters',
-    min_length = 10#sentinel default value
+    min_length = 10  # sentinel default value
 
     def __init__(self, *args, **kwargs):
         super(EditorField, self).__init__(*args, **kwargs)
         self.required = True
-        self.widget = forms.Textarea(attrs={'id':'editor'})
-        self.label  = _('content')
+        self.widget = forms.Textarea(attrs={'id': 'editor'})
+        self.label = _('content')
         self.help_text = u''
         self.initial = ''
 
@@ -218,32 +284,44 @@ class EditorField(forms.CharField):
                 self.length_error_template_singular,
                 self.length_error_template_plural,
                 self.min_length
-            ) % self.min_length 
+            ) % self.min_length
             raise forms.ValidationError(msg)
         return value
 
+
 class QuestionEditorField(EditorField):
+    """Editor field for the questions"""
+
     def __init__(self, *args, **kwargs):
         super(QuestionEditorField, self).__init__(*args, **kwargs)
-        self.length_error_template_singular = 'question body must be > %d character'
-        self.length_error_template_plural = 'question body must be > %d characters'
+        self.length_error_template_singular = \
+            'question body must be > %d character'
+        self.length_error_template_plural = \
+            'question body must be > %d characters'
         self.min_length = askbot_settings.MIN_QUESTION_BODY_LENGTH
 
+
 class AnswerEditorField(EditorField):
+    """Editor field for answers"""
+
     def __init__(self, *args, **kwargs):
         super(AnswerEditorField, self).__init__(*args, **kwargs)
         self.length_error_template_singular = 'answer must be > %d character'
         self.length_error_template_plural = 'answer must be > %d characters'
         self.min_length = askbot_settings.MIN_ANSWER_BODY_LENGTH
 
+
 class TagNamesField(forms.CharField):
+    """field that receives AskBot tag names"""
+
     def __init__(self, *args, **kwargs):
         super(TagNamesField, self).__init__(*args, **kwargs)
         self.required = askbot_settings.TAGS_ARE_REQUIRED
-        self.widget = forms.TextInput(attrs={'size' : 50, 'autocomplete' : 'off'})
+        self.widget = forms.TextInput(
+            attrs={'size': 50, 'autocomplete': 'off'}
+        )
         self.max_length = 255
         self.label = _('tags')
-        #self.help_text = _('please use space to separate tags (this enables autocomplete feature)')
         self.help_text = ungettext_lazy(
             'Tags are short keywords, with no spaces within. '
             'Up to %(max_tags)d tag can be used.',
@@ -253,38 +331,16 @@ class TagNamesField(forms.CharField):
         ) % {'max_tags': askbot_settings.MAX_TAGS_PER_POST}
         self.initial = ''
 
-    def need_mandatory_tags(self):
-        """true, if list of mandatory tags is not empty"""
-        from askbot import models
-        return askbot_settings.TAGS_ARE_REQUIRED and len(models.tag.get_mandatory_tags()) > 0
-
-    def tag_string_matches(self, tag_string, mandatory_tag):
-        """true if tag string matches the mandatory tag"""
-        if mandatory_tag.endswith('*'):
-            return tag_string.startswith(mandatory_tag[:-1])
-        else:
-            return tag_string == mandatory_tag
-
-    def mandatory_tag_missing(self, tag_strings):
-        """true, if mandatory tag is not present in the list
-        of ``tag_strings``"""
-        from askbot import models
-        mandatory_tags = models.tag.get_mandatory_tags()
-        for mandatory_tag in mandatory_tags:
-            for tag_string in tag_strings:
-                if self.tag_string_matches(tag_string, mandatory_tag):
-                    return False
-        return True
-
     def clean(self, value):
         from askbot import models
         value = super(TagNamesField, self).clean(value)
         data = value.strip()
         if len(data) < 1:
             if askbot_settings.TAGS_ARE_REQUIRED:
-                    raise forms.ValidationError(_('tags are required'))
+                raise forms.ValidationError(_('tags are required'))
             else:
-                return ''#don't test for required characters when tags is ''
+                #don't test for required characters when tags is ''
+                return ''
         split_re = re.compile(const.TAG_SPLIT_REGEX)
         tag_strings = split_re.split(data)
         entered_tags = []
@@ -294,11 +350,11 @@ class TagNamesField(forms.CharField):
             msg = ungettext_lazy(
                         'please use %(tag_count)d tag or less',
                         'please use %(tag_count)d tags or less',
-                        tag_count) % {'tag_count':max_tags}
+                        tag_count) % {'tag_count': max_tags}
             raise forms.ValidationError(msg)
 
-        if self.need_mandatory_tags():
-            if self.mandatory_tag_missing(tag_strings):
+        if need_mandatory_tags():
+            if mandatory_tag_missing_in_list(tag_strings):
                 msg = _(
                     'At least one of the following tags is required : %(tags)s'
                 ) % {'tags': get_text_list(models.tag.get_mandatory_tags())}
@@ -307,18 +363,22 @@ class TagNamesField(forms.CharField):
         for tag in tag_strings:
             tag_length = len(tag)
             if tag_length > askbot_settings.MAX_TAG_LENGTH:
-                #singular form is odd in english, but required for pluralization
-                #in other languages
-                msg = ungettext_lazy('each tag must be shorter than %(max_chars)d character',#odd but added for completeness
-                                'each tag must be shorter than %(max_chars)d characters',
-                                tag_length) % {'max_chars':tag_length}
+                #singular form is odd in english, but
+                #required for pluralization
+                #in other languages, odd but added for completeness
+                msg = ungettext_lazy(
+                    'each tag must be shorter than %(max_chars)d character',
+                    'each tag must be shorter than %(max_chars)d characters',
+                    tag_length
+                ) % {'max_chars': tag_length}
                 raise forms.ValidationError(msg)
 
             #todo - this needs to come from settings
             tagname_re = re.compile(const.TAG_REGEX, re.UNICODE)
             if not tagname_re.search(tag):
                 raise forms.ValidationError(_(
-                    'In tags, please use letters, numbers and characters "-+.#"'
+                    'In tags, please use letters, '
+                    'numbers and characters "-+.#"'
                 ))
             #only keep unique tags
             if tag not in entered_tags:
@@ -340,7 +400,7 @@ class TagNamesField(forms.CharField):
                     #because we need tag name cases to be the same
                     #as those stored in the database
                     stored_tag = models.Tag.objects.get(
-                                            name__iexact = entered_tag
+                                            name__iexact=entered_tag
                                         )
                     if stored_tag.name not in cleaned_entered_tags:
                         cleaned_entered_tags.append(stored_tag.name)
@@ -349,30 +409,54 @@ class TagNamesField(forms.CharField):
 
         return u' '.join(cleaned_entered_tags)
 
+
 class WikiField(forms.BooleanField):
+    """Rendered as checkbox turning post into
+    "community wiki"
+    """
+
     def __init__(self, *args, **kwargs):
         super(WikiField, self).__init__(*args, **kwargs)
         self.required = False
         self.initial = False
-        self.label  = _('community wiki (karma is not awarded & many others can edit wiki post)')
-        self.help_text = _('if you choose community wiki option, the question and answer do not generate points and name of author will not be shown')
+        self.label = _(
+            'community wiki (karma is not awarded & '
+            'many others can edit wiki post)'
+        )
+        self.help_text = _(
+            'if you choose community wiki option, the question '
+            'and answer do not generate points and name of '
+            'author will not be shown'
+        )
+
     def clean(self, value):
         return value and askbot_settings.WIKI_ON
 
+
 class EmailNotifyField(forms.BooleanField):
+    """Rendered as checkbox which turns on
+    email notifications on the post"""
     def __init__(self, *args, **kwargs):
         super(EmailNotifyField, self).__init__(*args, **kwargs)
         self.required = False
         self.widget.attrs['class'] = 'nomargin'
 
+
 class SummaryField(forms.CharField):
+
     def __init__(self, *args, **kwargs):
         super(SummaryField, self).__init__(*args, **kwargs)
         self.required = False
-        self.widget = forms.TextInput(attrs={'size' : 50, 'autocomplete' : 'off'})
+        self.widget = forms.TextInput(
+            attrs={'size': 50, 'autocomplete': 'off'}
+        )
         self.max_length = 300
-        self.label  = _('update summary:')
-        self.help_text = _('enter a brief summary of your revision (e.g. fixed spelling, grammar, improved style, this field is optional)')
+        self.label = _('update summary:')
+        self.help_text = _(
+            'enter a brief summary of your revision (e.g. '
+            'fixed spelling, grammar, improved style, this '
+            'field is optional)'
+        )
 
 
 class DumpUploadForm(forms.Form):
@@ -382,6 +466,7 @@ class DumpUploadForm(forms.Form):
     """
     dump_file = forms.FileField()
 
+
 class ShowQuestionForm(forms.Form):
     """Cleans data necessary to access answers and comments
     by the respective comment or answer id - necessary
@@ -389,10 +474,10 @@ class ShowQuestionForm(forms.Form):
     on the page other than the first page of answers to a question.
     Same for the answers that are shown on the later pages.
     """
-    answer = forms.IntegerField(required = False)
-    comment = forms.IntegerField(required = False)
-    page = forms.IntegerField(required = False)
-    sort = forms.CharField(required = False)
+    answer = forms.IntegerField(required=False)
+    comment = forms.IntegerField(required=False)
+    page = forms.IntegerField(required=False)
+    sort = forms.CharField(required=False)
 
     def __init__(self, data, default_sort_method):
         super(ShowQuestionForm, self).__init__(data)
@@ -436,6 +521,7 @@ class ShowQuestionForm(forms.Form):
         self.cleaned_data = out_data
         return out_data
 
+
 class ChangeUserReputationForm(forms.Form):
     """Form that allows moderators and site administrators
     to adjust reputation of users.
@@ -445,13 +531,15 @@ class ChangeUserReputationForm(forms.Form):
     """
 
     user_reputation_delta = forms.IntegerField(
-                                    min_value = 1,
-                                    label = _('Enter number of points to add or subtract')
-                                )
-    comment = forms.CharField(max_length = 128)
+                            min_value=1,
+                            label=_(
+                                'Enter number of points to add or subtract'
+                            )
+                        )
+    comment = forms.CharField(max_length=128)
 
     def clean_comment(self):
-        if 'comment' in  self.cleaned_data:
+        if 'comment' in self.cleaned_data:
             comment = self.cleaned_data['comment'].strip()
             if comment == '':
                 del self.cleaned_data['comment']
@@ -485,9 +573,7 @@ class ChangeUserStatusForm(forms.Form):
     "moderation" tab
     """
 
-    user_status = forms.ChoiceField(
-                            label = _('Change status to'),
-                        )
+    user_status = forms.ChoiceField(label=_('Change status to'))
 
     def __init__(self, *arg, **kwarg):
 
@@ -508,12 +594,12 @@ class ChangeUserStatusForm(forms.Form):
 
         #remove current status of the "subject" user from choices
         user_status_choices = filter_choices(
-                                        remove_choices = [subject.status, ],
-                                        from_choices = user_status_choices
+                                        remove_choices=[subject.status, ],
+                                        from_choices=user_status_choices
                                     )
 
         #add prompt option
-        user_status_choices = ( ('select', _('which one?')), ) \
+        user_status_choices = (('select', _('which one?')), ) \
                                 + user_status_choices
 
         self.fields['user_status'].choices = user_status_choices
@@ -561,41 +647,39 @@ class ChangeUserStatusForm(forms.Form):
                 msg = _(
                         'If you wish to change %(username)s\'s status, '
                         'please make a meaningful selection.'
-                    ) % {'username': self.subject.username }
+                    ) % {'username': self.subject.username}
                 raise forms.ValidationError(msg)
 
         return self.cleaned_data
 
+
 class SendMessageForm(forms.Form):
     subject_line = forms.CharField(
-                            label = _('Subject line'),
-                            max_length = 64,
-                            widget = forms.TextInput(
-                                            attrs = {'size':64},
-                                        )
-                        )
+                        label=_('Subject line'),
+                        max_length=64,
+                        widget=forms.TextInput(attrs={'size': 64}, )
+                    )
     body_text = forms.CharField(
-                            label = _('Message text'),
-                            max_length = 1600,
-                            widget = forms.Textarea(
-                                            attrs = {'cols':64}
-                                        )
+                            label=_('Message text'),
+                            max_length=1600,
+                            widget=forms.Textarea(attrs={'cols': 64})
                         )
 
 
 class NotARobotForm(forms.Form):
     recaptcha = RecaptchaField(
-                    private_key = askbot_settings.RECAPTCHA_SECRET,
-                    public_key = askbot_settings.RECAPTCHA_KEY
+                    private_key=askbot_settings.RECAPTCHA_SECRET,
+                    public_key=askbot_settings.RECAPTCHA_KEY
                 )
 
+
 class FeedbackForm(forms.Form):
     name = forms.CharField(label=_('Your name (optional):'), required=False)
     email = forms.EmailField(label=_('Email:'), required=False)
     message = forms.CharField(
         label=_('Your message:'),
         max_length=800,
-        widget=forms.Textarea(attrs={'cols':60})
+        widget=forms.Textarea(attrs={'cols': 60})
     )
     no_email = forms.BooleanField(
         label=_("I don't want to give my email or receive a response:"),
@@ -612,19 +696,21 @@ class FeedbackForm(forms.Form):
 
     def _add_recaptcha_field(self):
         self.fields['recaptcha'] = RecaptchaField(
-                                private_key = askbot_settings.RECAPTCHA_SECRET,
-                                public_key = askbot_settings.RECAPTCHA_KEY
-                                )
+                            private_key=askbot_settings.RECAPTCHA_SECRET,
+                            public_key=askbot_settings.RECAPTCHA_KEY
+                        )
 
     def clean(self):
         super(FeedbackForm, self).clean()
         if not self.is_auth:
-            if not self.cleaned_data['no_email'] and not self.cleaned_data['email']:
+            if not self.cleaned_data['no_email'] \
+                and not self.cleaned_data['email']:
                 msg = _('Please mark "I dont want to give my mail" field.')
                 self._errors['email'] = self.error_class([msg])
 
         return self.cleaned_data
 
+
 class FormWithHideableFields(object):
     """allows to swap a field widget to HiddenInput() and back"""
 
@@ -646,6 +732,7 @@ class FormWithHideableFields(object):
         if name in self.__hidden_fields:
             self.fields[name] = self.__hidden_fields.pop(name)
 
+
 class AskForm(forms.Form, FormWithHideableFields):
     """the form used to askbot questions
     field ask_anonymously is shown to the user if the
@@ -654,40 +741,51 @@ class AskForm(forms.Form, FormWithHideableFields):
     in the cleaned data, and will evaluate to False if the
     settings forbids anonymous asking
     """
-    title  = TitleField()
-    text   = QuestionEditorField()
-    tags   = TagNamesField()
+    title = TitleField()
+    text = QuestionEditorField()
+    tags = TagNamesField()
     wiki = WikiField()
     ask_anonymously = forms.BooleanField(
-        label = _('ask anonymously'),
-        help_text = _(
+        label=_('ask anonymously'),
+        help_text=_(
             'Check if you do not want to reveal your name '
             'when asking this question'
         ),
-        required = False,
+        required=False,
+    )
+    openid = forms.CharField(
+        required=False, max_length=255,
+        widget=forms.TextInput(attrs={'size': 40, 'class': 'openid-input'})
+    )
+    user = forms.CharField(
+        required=False, max_length=255,
+        widget=forms.TextInput(attrs={'size': 35})
+    )
+    email = forms.CharField(
+        required=False, max_length=255,
+        widget=forms.TextInput(attrs={'size': 35})
     )
-    openid = forms.CharField(required=False, max_length=255, widget=forms.TextInput(attrs={'size' : 40, 'class':'openid-input'}))
-    user   = forms.CharField(required=False, max_length=255, widget=forms.TextInput(attrs={'size' : 35}))
-    email  = forms.CharField(required=False, max_length=255, widget=forms.TextInput(attrs={'size' : 35}))
 
     def __init__(self, *args, **kwargs):
         super(AskForm, self).__init__(*args, **kwargs)
         #hide ask_anonymously field
-        if askbot_settings.ALLOW_ASK_ANONYMOUSLY == False:
+        if askbot_settings.ALLOW_ASK_ANONYMOUSLY is False:
             self.hide_field('ask_anonymously')
 
     def clean_ask_anonymously(self):
         """returns false if anonymous asking is not allowed
         """
-        if askbot_settings.ALLOW_ASK_ANONYMOUSLY == False:
+        if askbot_settings.ALLOW_ASK_ANONYMOUSLY is False:
             self.cleaned_data['ask_anonymously'] = False
         return self.cleaned_data['ask_anonymously']
 
+
 ASK_BY_EMAIL_SUBJECT_HELP = _(
     'Subject line is expected in the format: '
     '[tag1, tag2, tag3,...] question title'
 )
 
+
 class AskByEmailForm(forms.Form):
     """:class:`~askbot.forms.AskByEmailForm`
     validates question data, where question was posted
@@ -706,12 +804,13 @@ class AskByEmailForm(forms.Form):
     * ``email`` - email address
     * ``title`` - question title
     * ``tagnames`` - tag names all in one string
-    * ``body_text`` - body of question text - a pass-through, no extra validation
+    * ``body_text`` - body of question text -
+      a pass-through, no extra validation
     """
-    sender = forms.CharField(max_length = 255)
+    sender = forms.CharField(max_length=255)
     subject = forms.CharField(
-        max_length = 255,
-        error_messages = {
+        max_length=255,
+        error_messages={
             'required': ASK_BY_EMAIL_SUBJECT_HELP
         }
     )
@@ -743,17 +842,19 @@ class AskByEmailForm(forms.Form):
         match = subject_re.match(raw_subject)
         if match:
             #make raw tags comma-separated
-            if match.group(1) is None:#no tags
+            if match.group(1) is None:  # no tags
                 self.cleaned_data['tagnames'] = ''
             else:
-                tagnames = match.group(1).replace(';',',')
+                tagnames = match.group(1).replace(';', ',')
 
                 #pre-process tags
                 tag_list = [tag.strip() for tag in tagnames.split(',')]
                 tag_list = [re.sub(r'\s+', ' ', tag) for tag in tag_list]
+
                 if askbot_settings.REPLACE_SPACE_WITH_DASH_IN_EMAILED_TAGS:
                     tag_list = [tag.replace(' ', '-') for tag in tag_list]
-                tagnames = ' '.join(tag_list)#todo: use tag separator char here
+                #todo: use tag separator char here
+                tagnames = ' '.join(tag_list)
 
                 #clean tags - may raise ValidationError
                 self.cleaned_data['tagnames'] = TagNamesField().clean(tagnames)
@@ -765,22 +866,36 @@ class AskByEmailForm(forms.Form):
             raise forms.ValidationError(ASK_BY_EMAIL_SUBJECT_HELP)
         return self.cleaned_data['subject']
 
+
 class AnswerForm(forms.Form):
-    text   = AnswerEditorField()
-    wiki   = WikiField()
-    openid = forms.CharField(required=False, max_length=255, widget=forms.TextInput(attrs={'size' : 40, 'class':'openid-input'}))
-    user   = forms.CharField(required=False, max_length=255, widget=forms.TextInput(attrs={'size' : 35}))
-    email  = forms.CharField(required=False, max_length=255, widget=forms.TextInput(attrs={'size' : 35}))
-    email_notify = EmailNotifyField(initial = False)
+    text = AnswerEditorField()
+    wiki = WikiField()
+    openid = forms.CharField(
+        required=False, max_length=255,
+        widget=forms.TextInput(attrs={'size': 40, 'class': 'openid-input'})
+    )
+    user = forms.CharField(
+        required=False, max_length=255,
+        widget=forms.TextInput(attrs={'size': 35})
+    )
+    email = forms.CharField(
+        required=False, max_length=255,
+        widget=forms.TextInput(attrs={'size': 35})
+    )
+    email_notify = EmailNotifyField(initial=False)
+
     def __init__(self, *args, **kwargs):
         super(AnswerForm, self).__init__(*args, **kwargs)
-        self.fields['email_notify'].widget.attrs['id'] = 'question-subscribe-updates'
+        self.fields['email_notify'].widget.attrs['id'] = \
+                                    'question-subscribe-updates'
+
 
 class VoteForm(forms.Form):
     """form used in ajax vote view (only comment_upvote so far)
     """
     post_id = forms.IntegerField()
-    cancel_vote = forms.CharField()#char because it is 'true' or 'false' as string
+    # char because it is 'true' or 'false' as string
+    cancel_vote = forms.CharField()
 
     def clean_cancel_vote(self):
         val = self.cleaned_data['cancel_vote']
@@ -790,7 +905,9 @@ class VoteForm(forms.Form):
             result = False
         else:
             del self.cleaned_data['cancel_vote']
-            raise forms.ValidationError('either "true" or "false" strings expected')
+            raise forms.ValidationError(
+                    'either "true" or "false" strings expected'
+                )
         self.cleaned_data['cancel_vote'] = result
         return self.cleaned_data['cancel_vote']
 
@@ -798,43 +915,57 @@ class VoteForm(forms.Form):
 class CloseForm(forms.Form):
     reason = forms.ChoiceField(choices=const.CLOSE_REASONS)
 
+
 class RetagQuestionForm(forms.Form):
     tags = TagNamesField()
-    # initialize the default values
+
     def __init__(self, question, *args, **kwargs):
+        """initialize the default values"""
         super(RetagQuestionForm, self).__init__(*args, **kwargs)
         self.fields['tags'].initial = question.thread.tagnames
 
+
 class RevisionForm(forms.Form):
     """
     Lists revisions of a Question or Answer
     """
-    revision = forms.ChoiceField(widget=forms.Select(attrs={'style' : 'width:520px'}))
+    revision = forms.ChoiceField(
+                    widget=forms.Select(
+                        attrs={'style': 'width:520px'}
+                    )
+                )
 
     def __init__(self, post, latest_revision, *args, **kwargs):
         super(RevisionForm, self).__init__(*args, **kwargs)
         revisions = post.revisions.values_list(
-            'revision', 'author__username', 'revised_at', 'summary')
+            'revision', 'author__username', 'revised_at', 'summary'
+        )
         date_format = '%c'
-        self.fields['revision'].choices = [
-            (r[0], u'%s - %s (%s) %s' % (r[0], r[1], r[2].strftime(date_format), r[3]))
-            for r in revisions]
+        rev_choices = list()
+        for r in revisions:
+            rev_details = u'%s - %s (%s) %s' % (
+                r[0], r[1], r[2].strftime(date_format), r[3]
+            )
+            rev_choices.append((r[0], rev_details))
+
+        self.fields['revision'].choices = rev_choices
         self.fields['revision'].initial = latest_revision.revision
 
+
 class EditQuestionForm(forms.Form, FormWithHideableFields):
-    title  = TitleField()
-    text   = QuestionEditorField()
-    tags   = TagNamesField()
+    title = TitleField()
+    text = QuestionEditorField()
+    tags = TagNamesField()
     summary = SummaryField()
     wiki = WikiField()
     reveal_identity = forms.BooleanField(
-        help_text = _(
+        help_text=_(
             'You have asked this question anonymously, '
             'if you decide to reveal your identity, please check '
             'this box.'
         ),
-        label = _('reveal identity'),
-        required = False,
+        label=_('reveal identity'),
+        required=False,
     )
 
     #todo: this is odd that this form takes question as an argument
@@ -855,8 +986,8 @@ class EditQuestionForm(forms.Form, FormWithHideableFields):
     def can_stay_anonymous(self):
         """determines if the user cat keep editing the question
         anonymously"""
-        return (askbot_settings.ALLOW_ASK_ANONYMOUSLY \
-            and self.question.is_anonymous \
+        return (askbot_settings.ALLOW_ASK_ANONYMOUSLY
+            and self.question.is_anonymous
             and self.user.is_owner_of(self.question)
         )
 
@@ -882,7 +1013,7 @@ class EditQuestionForm(forms.Form, FormWithHideableFields):
         """
         value = self.cleaned_data['reveal_identity']
         if self.question.is_anonymous:
-            if value == True:
+            if value is True:
                 if self.user.is_owner_of(self.question):
                     #regardless of the ALLOW_ASK_ANONYMOUSLY
                     return True
@@ -900,7 +1031,7 @@ class EditQuestionForm(forms.Form, FormWithHideableFields):
             else:
                 can_ask_anon = askbot_settings.ALLOW_ASK_ANONYMOUSLY
                 is_owner = self.user.is_owner_of(self.question)
-                if can_ask_anon == False and is_owner:
+                if can_ask_anon is False and is_owner:
                     self.show_field('reveal_identity')
                     raise forms.ValidationError(
                         _(
@@ -924,11 +1055,12 @@ class EditQuestionForm(forms.Form, FormWithHideableFields):
         """
         reveal_identity = self.cleaned_data.get('reveal_identity', False)
         stay_anonymous = False
-        if reveal_identity == False and self.can_stay_anonymous():
+        if reveal_identity is False and self.can_stay_anonymous():
             stay_anonymous = True
         self.cleaned_data['stay_anonymous'] = stay_anonymous
         return self.cleaned_data
 
+
 class EditAnswerForm(forms.Form):
     text = AnswerEditorField()
     summary = SummaryField()
@@ -939,40 +1071,42 @@ class EditAnswerForm(forms.Form):
         self.fields['text'].initial = revision.text
         self.fields['wiki'].initial = answer.wiki
 
+
 class EditTagWikiForm(forms.Form):
-    text = forms.CharField(required = False)
+    text = forms.CharField(required=False)
     tag_id = forms.IntegerField()
 
+
 class EditUserForm(forms.Form):
     email = forms.EmailField(
                     label=u'Email',
                     required=True,
                     max_length=255,
-                    widget=forms.TextInput(attrs={'size' : 35})
+                    widget=forms.TextInput(attrs={'size': 35})
                 )
 
     realname = forms.CharField(
                         label=_('Real name'),
                         required=False,
                         max_length=255,
-                        widget=forms.TextInput(attrs={'size' : 35})
+                        widget=forms.TextInput(attrs={'size': 35})
                     )
 
     website = forms.URLField(
                         label=_('Website'),
                         required=False,
                         max_length=255,
-                        widget=forms.TextInput(attrs={'size' : 35})
+                        widget=forms.TextInput(attrs={'size': 35})
                     )
 
     city = forms.CharField(
                         label=_('City'),
                         required=False,
                         max_length=255,
-                        widget=forms.TextInput(attrs={'size' : 35})
+                        widget=forms.TextInput(attrs={'size': 35})
                     )
 
-    country = CountryField(required = False)
+    country = CountryField(required=False)
 
     show_country = forms.BooleanField(
                         label=_('Show country'),
@@ -986,15 +1120,18 @@ class EditUserForm(forms.Form):
 
     birthday = forms.DateField(
                         label=_('Date of birth'),
-                        help_text=_('will not be shown, used to calculate age, format: YYYY-MM-DD'),
+                        help_text=_(
+                            'will not be shown, used to calculate '
+                            'age, format: YYYY-MM-DD'
+                        ),
                         required=False,
-                        widget=forms.TextInput(attrs={'size' : 35})
+                        widget=forms.TextInput(attrs={'size': 35})
                     )
 
     about = forms.CharField(
                         label=_('Profile'),
                         required=False,
-                        widget=forms.Textarea(attrs={'cols' : 60})
+                        widget=forms.Textarea(attrs={'cols': 60})
                     )
 
     def __init__(self, user, *args, **kwargs):
@@ -1008,7 +1145,7 @@ class EditUserForm(forms.Form):
         self.fields['realname'].initial = user.real_name
         self.fields['website'].initial = user.website
         self.fields['city'].initial = user.location
-        if user.country == None:
+        if user.country is None:
             country = 'unknown'
         else:
             country = user.country
@@ -1026,24 +1163,32 @@ class EditUserForm(forms.Form):
         """For security reason one unique email in database"""
         if self.user.email != self.cleaned_data['email']:
             #todo dry it, there is a similar thing in openidauth
-            if askbot_settings.EMAIL_UNIQUE == True:
+            if askbot_settings.EMAIL_UNIQUE is True:
                 if 'email' in self.cleaned_data:
                     try:
-                        User.objects.get(email = self.cleaned_data['email'])
+                        User.objects.get(email=self.cleaned_data['email'])
                     except User.DoesNotExist:
                         return self.cleaned_data['email']
                     except User.MultipleObjectsReturned:
-                        raise forms.ValidationError(_('this email has already been registered, please use another one'))
-                    raise forms.ValidationError(_('this email has already been registered, please use another one'))
+                        raise forms.ValidationError(_(
+                            'this email has already been registered, '
+                            'please use another one')
+                        )
+                    raise forms.ValidationError(_(
+                        'this email has already been registered, '
+                        'please use another one')
+                    )
         return self.cleaned_data['email']
 
+
 class TagFilterSelectionForm(forms.ModelForm):
     email_tag_filter_strategy = forms.ChoiceField(
-        choices = const.TAG_DISPLAY_FILTER_STRATEGY_CHOICES,
-        initial = const.EXCLUDE_IGNORED,
-        label = _('Choose email tag filter'),
-        widget = forms.RadioSelect
+        choices=const.TAG_DISPLAY_FILTER_STRATEGY_CHOICES,
+        initial=const.EXCLUDE_IGNORED,
+        label=_('Choose email tag filter'),
+        widget=forms.RadioSelect
     )
+
     class Meta:
         model = User
         fields = ('email_tag_filter_strategy',)
@@ -1060,31 +1205,31 @@ class TagFilterSelectionForm(forms.ModelForm):
 class EmailFeedSettingField(forms.ChoiceField):
     def __init__(self, *arg, **kwarg):
         kwarg['choices'] = const.NOTIFICATION_DELIVERY_SCHEDULE_CHOICES
-        #kwarg['initial'] = askbot_settings.DEFAULT_NOTIFICATION_DELIVERY_SCHEDULE
         kwarg['widget'] = forms.RadioSelect
         super(EmailFeedSettingField, self).__init__(*arg, **kwarg)
 
+
 class EditUserEmailFeedsForm(forms.Form):
     FORM_TO_MODEL_MAP = {
-        'all_questions':'q_all',
-        'asked_by_me':'q_ask',
-        'answered_by_me':'q_ans',
-        'individually_selected':'q_sel',
-        'mentions_and_comments':'m_and_c',
+        'all_questions': 'q_all',
+        'asked_by_me': 'q_ask',
+        'answered_by_me': 'q_ans',
+        'individually_selected': 'q_sel',
+        'mentions_and_comments': 'm_and_c',
     }
     NO_EMAIL_INITIAL = {
-        'all_questions':'n',
-        'asked_by_me':'n',
-        'answered_by_me':'n',
-        'individually_selected':'n',
-        'mentions_and_comments':'n',
+        'all_questions': 'n',
+        'asked_by_me': 'n',
+        'answered_by_me': 'n',
+        'individually_selected': 'n',
+        'mentions_and_comments': 'n',
     }
     INSTANT_EMAIL_INITIAL = {
-        'all_questions':'i',
-        'asked_by_me':'i',
-        'answered_by_me':'i',
-        'individually_selected':'i',
-        'mentions_and_comments':'i',
+        'all_questions': 'i',
+        'asked_by_me': 'i',
+        'answered_by_me': 'i',
+        'individually_selected': 'i',
+        'mentions_and_comments': 'i',
     }
 
     asked_by_me = EmailFeedSettingField(
@@ -1107,7 +1252,7 @@ class EditUserEmailFeedsForm(forms.Form):
     def set_initial_values(self, user=None):
         from askbot import models
         KEY_MAP = dict([(v, k) for k, v in self.FORM_TO_MODEL_MAP.iteritems()])
-        if user != None:
+        if user is not None:
             settings = models.EmailFeedSetting.objects.filter(subscriber=user)
             initial_values = {}
             for setting in settings:
@@ -1137,7 +1282,7 @@ class EditUserEmailFeedsForm(forms.Form):
         """
         return self.FORM_TO_MODEL_MAP.values()
 
-    def set_frequency(self, frequency = 'n'):
+    def set_frequency(self, frequency='n'):
         data = {
             'all_questions': frequency,
             'asked_by_me': frequency,
@@ -1149,9 +1294,9 @@ class EditUserEmailFeedsForm(forms.Form):
             self.cleaned_data = data
         self.initial = data
 
-    def save(self,user,save_unbound=False):
-        """
-            with save_unbound==True will bypass form validation and save initial values
+    def save(self, user, save_unbound=False):
+        """with save_unbound==True will bypass form
+        validation and save initial values
         """
         from askbot import models
         changed = False
@@ -1179,23 +1324,25 @@ class EditUserEmailFeedsForm(forms.Form):
                 user.followed_threads.clear()
         return changed
 
+
 class SubscribeForEmailUpdatesField(forms.ChoiceField):
     """a simple yes or no field to subscribe for email or not"""
     def __init__(self, **kwargs):
         kwargs['widget'] = forms.widgets.RadioSelect
         kwargs['error_messages'] = {
-            'required':_('please choose one of the options above')
+            'required': _('please choose one of the options above')
         }
         kwargs['choices'] = (
-            ('y',_('okay, let\'s try!')),
+            ('y', _('okay, let\'s try!')),
             (
                 'n',
-                _('no %(sitename)s email please, thanks') \
+                _('no %(sitename)s email please, thanks')
                     % {'sitename': askbot_settings.APP_SHORT_NAME}
             )
         )
         super(SubscribeForEmailUpdatesField, self).__init__(**kwargs)
 
+
 class SimpleEmailSubscribeForm(forms.Form):
     subscribe = SubscribeForEmailUpdatesField()
 
@@ -1211,11 +1358,13 @@ class SimpleEmailSubscribeForm(forms.Form):
             email_settings_form = EFF(initial=EFF.NO_EMAIL_INITIAL)
         email_settings_form.save(user, save_unbound=True)
 
+
 class GroupLogoURLForm(forms.Form):
     """form for saving group logo url"""
     group_id = forms.IntegerField()
     image_url = forms.CharField()
 
+
 class EditGroupMembershipForm(forms.Form):
     """a form for adding or removing users
     to and from user groups"""
@@ -1231,11 +1380,12 @@ class EditGroupMembershipForm(forms.Form):
             raise forms.ValidationError('invalid action')
         return action
 
+
 class EditRejectReasonForm(forms.Form):
-    reason_id = forms.IntegerField(required = False)
+    reason_id = forms.IntegerField(required=False)
     title = CountedWordsField(
-        min_words = 1, max_words = 4, field_name = _('Title')
+        min_words=1, max_words=4, field_name=_('Title')
     )
     details = CountedWordsField(
-        min_words = 6, field_name = _('Description')
+        min_words=6, field_name=_('Description')
     )
diff --git a/askbot/models/__init__.py b/askbot/models/__init__.py
index ed0d876a..1c884ed6 100644
--- a/askbot/models/__init__.py
+++ b/askbot/models/__init__.py
@@ -551,9 +551,16 @@ def user_assert_can_post_question(self):
     )
 
 
-def user_assert_can_post_answer(self):
+def user_assert_can_post_answer(self, thread = None):
     """same as user_can_post_question
     """
+    limit_answers = askbot_settings.LIMIT_ONE_ANSWER_PER_USER
+    if limit_answers and thread.has_answer_by_user(self):
+        message = _(
+            'Sorry, you already gave an answer, please edit it instead.'
+        )
+        raise askbot_exceptions.AnswerAlreadyGiven(message)
+
     self.assert_can_post_question()
 
 
@@ -1718,7 +1725,7 @@ def user_post_answer(
             assert(error_message is not None)
             raise django_exceptions.PermissionDenied(error_message)
 
-    self.assert_can_post_answer()
+    self.assert_can_post_answer(thread = question.thread)
 
     if getattr(question, 'post_type', '') != 'question':
         raise TypeError('question argument must be provided')
diff --git a/askbot/models/post.py b/askbot/models/post.py
index c08b940b..d61c1ae2 100644
--- a/askbot/models/post.py
+++ b/askbot/models/post.py
@@ -670,7 +670,7 @@ class Post(models.Model):
         does not talk to the actual cache system
         """
         self._cached_comments = comments
-    
+
     def get_cached_comments(self):
         try:
             return self._cached_comments
diff --git a/askbot/models/question.py b/askbot/models/question.py
index 1729b531..3453ff7c 100644
--- a/askbot/models/question.py
+++ b/askbot/models/question.py
@@ -498,6 +498,14 @@ class Thread(models.Model):
                 output += answer.format_for_email_as_subthread()
         return output
 
+    def get_answers_by_user(self, user):
+        """regardless - deleted or not"""
+        return self.posts.filter(post_type = 'answer', author = user)
+
+    def has_answer_by_user(self, user):
+        #use len to cache the queryset
+        return len(self.get_answers_by_user(user)) > 0
+
     def tagname_meta_generator(self):
         return u','.join([unicode(tag) for tag in self.get_tag_names()])
 
@@ -920,6 +928,7 @@ class AnonymousQuestion(AnonymousContent):
 
     def publish(self,user):
         added_at = datetime.datetime.now()
+        #todo: wrong - use User.post_question() instead
         Thread.objects.create_new(
             title = self.title,
             added_at = added_at,
diff --git a/askbot/skins/default/templates/meta/bottom_scripts.html b/askbot/skins/default/templates/meta/bottom_scripts.html
index 2603ec31..6c132203 100644
--- a/askbot/skins/default/templates/meta/bottom_scripts.html
+++ b/askbot/skins/default/templates/meta/bottom_scripts.html
@@ -25,7 +25,7 @@
     {% if settings.DEBUG %}
         src="{{"/js/jquery-1.7.2.min.js"|media}}"
     {% else %}
-        src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"
+        src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"
     {% endif %}
 ></script>
 <!-- History.js --> 
@@ -42,33 +42,36 @@
     </script>
 {% endif %}
 <script type="text/javascript">
-{% if active_tab != "tags" and active_tab != "users" %}
     $(document).ready(function(){
-        if (Modernizr.history) {
-          // history management works!
-        } else {
-          // no history support :(
-          //hash = unescape(window.location.hash).replace('#','').split("?")[0]
-          hash = History.unescapeHash(window.location.hash).replace('#','').split("?")[0]
-          if (hash.substring(0,11)==askbot['urls']['questions']){
-            url = hash
-          }else{
-            url = askbot['urls']['questions']+hash
-          }
-          if (hash !== ''){
-              window.location = 'http://'+window.location.host+url
-          }
-        }
-
+        {% if active_tab == 'questions' %}
+            if (Modernizr.history) {
+                // history management works!
+            } else {
+                // no history support :(
+                //hash = unescape(window.location.hash).replace('#','').split("?")[0]
+                {# todo: fix this evil code!!! #}
+                var hash = History.unescapeHash(window.location.hash).replace('#','').split("?")[0];
+                var questions_url = askbot['urls']['questions'];
+                if (hash.substring(0, questions_url.length) === questions_url) {
+                    var url = hash;
+                } else {
+                    var url = questions_url + hash;
+                }
+                if (hash !== '' && hash !== undefined && url !== undefined){
+                    {# was this causing strange redirects in IE??? #}
+                    window.location = 'http://' + window.location.host + url;
+                }
+            }
+        {% endif %}
         // focus input on the search bar endcomment
-        {% if active_tab != "ask" %}
+        {% if active_tab in ('users', 'questions', 'tags') %}
             $('#keywords').focus();
-        {% else %}
+        {% elif active_tab == 'ask' %}
             $('#id_title').focus();
+        {% else %}
+            animateHashes();
         {% endif %}
-        animateHashes();
     });
-{% endif %}
 {% if user_messages %}
     $('#validate_email_alert').click(function(){notify.close(true)})
     notify.show();
diff --git a/askbot/skins/default/templates/question/content.html b/askbot/skins/default/templates/question/content.html
index f01c68e0..66b3014b 100644
--- a/askbot/skins/default/templates/question/content.html
+++ b/askbot/skins/default/templates/question/content.html
@@ -29,8 +29,16 @@
 {% endif %}
 
 {# ==== START: question/new_answer_form.html ==== #}
-{% include "question/new_answer_form.html" %}
-{# ==== END: question/new_answer_form.html ==== #}
+{# buttons below cannot be cached yet #}
+{% if user_already_gave_answer %}
+    <a
+        class="submit"
+        href="{% url "edit_answer" previous_answer.id %}"
+    >{% trans %}Edit Your Previous Answer{% endtrans %}</a>
+    <span>{% trans %}(only one answer per question is allowed){% endtrans %}</span>
+{% else %}
+    {% include "question/new_answer_form.html" %}
+{% endif %}
 {% if question.closed == False and request.user == question.author %}{# this is outside the form on purpose #}
 <input 
   type="button"
diff --git a/askbot/tests/badge_tests.py b/askbot/tests/badge_tests.py
index dbb37dde..b66eadcc 100644
--- a/askbot/tests/badge_tests.py
+++ b/askbot/tests/badge_tests.py
@@ -68,7 +68,8 @@ class BadgeTests(AskbotTestCase):
         self.assert_have_badge(badge_key, recipient = self.u2, expected_count = 1)
         
         #post another question and check that there are no new badges
-        answer2 = self.post_answer(user = self.u2, question = question)
+        question2 = self.post_question(user = self.u1)
+        answer2 = self.post_answer(user = self.u2, question = question2)
         answer2.score = min_score - 1
         answer2.save()
         self.u1.upvote(answer2)
@@ -269,7 +270,8 @@ class BadgeTests(AskbotTestCase):
         answer = self.post_answer(user = self.u2, question = question)
         self.u1.accept_best_answer(answer)
         self.assert_have_badge('scholar', recipient = self.u1)
-        answer2 = self.post_answer(user = self.u2, question = question)
+        question2 = self.post_question(user = self.u1)
+        answer2 = self.post_answer(user = self.u2, question = question2)
         self.u1.accept_best_answer(answer2)
         self.assert_have_badge(
             'scholar',
diff --git a/askbot/utils/forms.py b/askbot/utils/forms.py
index b8ed253b..ee7adf7e 100644
--- a/askbot/utils/forms.py
+++ b/askbot/utils/forms.py
@@ -108,7 +108,7 @@ class UserNameField(StrippedNonEmptyCharField):
             raise forms.ValidationError(self.error_messages['invalid'])
         if username in self.RESERVED_NAMES:
             raise forms.ValidationError(self.error_messages['forbidden'])
-        if slugify(username, force_unidecode = True) == '':
+        if slugify(username) == '':
             raise forms.ValidationError(self.error_messages['meaningless'])
         try:
             user = self.db_model.objects.get(
diff --git a/askbot/utils/slug.py b/askbot/utils/slug.py
index 58f228da..f9e30cbf 100644
--- a/askbot/utils/slug.py
+++ b/askbot/utils/slug.py
@@ -5,30 +5,63 @@ the setting was added just in case - if people actually
 want to see unicode characters in the slug. If this is the choice
 slug will be simply equal to the input text
 """
+import re
+import unicodedata
 from unidecode import unidecode
-from django.template import defaultfilters
+
 from django.conf import settings
-import re
+from django.template import defaultfilters
+from django.utils.encoding import smart_unicode
+
+
+# Extra characters outside of alphanumerics that we'll allow.
+SLUG_OK = '-_~'
+
 
-def slugify(input_text, max_length=50, force_unidecode = False):
+def unicode_slugify(s, ok=SLUG_OK, lower=True, spaces=False):
+    """Function copied from https://github.com/mozilla/unicode-slugify
+    because the author of the package never published it on pypi.
+
+    Copyright notice below applies just to this function
+    Copyright (c) 2011, Mozilla Foundation
+    All rights reserved.
+
+    L and N signify letter/number.
+    http://www.unicode.org/reports/tr44/tr44-4.html#GC_Values_Table
+    """
+    rv = []
+    for c in unicodedata.normalize('NFKC', smart_unicode(s)):
+        cat = unicodedata.category(c)[0]
+        if cat in 'LN' or c in ok:
+            rv.append(c)
+        if cat == 'Z':  # space
+            rv.append(' ')
+    new = ''.join(rv).strip()
+    if not spaces:
+        new = re.sub('[-\s]+', '-', new)
+    return new.lower() if lower else new
+
+
+def slugify(input_text, max_length=150):
     """custom slugify function that
     removes diacritic modifiers from the characters
     """
+    if input_text == '':
+        return input_text
+
     allow_unicode_slugs = getattr(settings, 'ALLOW_UNICODE_SLUGS', False)
-    if allow_unicode_slugs == False or force_unidecode == True:
-        if input_text == '':
-            return input_text
-        slug = defaultfilters.slugify(unidecode(input_text))
-        while len(slug) > max_length:
-            # try to shorten word by word until len(slug) <= max_length
-            temp = slug[:slug.rfind('-')]
-            if len(temp) > 0:
-                slug = temp
-            else:
-                #we have nothing left, do not apply the last crop,
-                #apply the cut-off directly
-                slug = slug[:max_length]
-                break
-        return slug
+    if allow_unicode_slugs:
+        slug = unicode_slugify(input_text)
     else:
-        return re.sub(r'\s+', '-', input_text.strip().lower())
+        slug = defaultfilters.slugify(unidecode(input_text))
+    while len(slug) > max_length:
+        # try to shorten word by word until len(slug) <= max_length
+        temp = slug[:slug.rfind('-')]
+        if len(temp) > 0:
+            slug = temp
+        else:
+            #we have nothing left, do not apply the last crop,
+            #apply the cut-off directly
+            slug = slug[:max_length]
+            break
+    return slug
diff --git a/askbot/views/readers.py b/askbot/views/readers.py
index c73b0c35..5f4d9ee4 100644
--- a/askbot/views/readers.py
+++ b/askbot/views/readers.py
@@ -455,7 +455,7 @@ def question(request, id):#refactor - long subroutine. display question body, an
         user_post_id_list = [
             id for id in post_to_author if post_to_author[id] == request.user.id
         ]
-        
+
     #resolve page number and comment number for permalinks
     show_comment_position = None
     if show_comment:
@@ -520,7 +520,7 @@ def question(request, id):#refactor - long subroutine. display question body, an
         is_cacheable = False
     elif show_comment_position > askbot_settings.MAX_COMMENTS_TO_SHOW:
         is_cacheable = False
-        
+
     answer_form = AnswerForm(
         initial = {
             'wiki': question_post.wiki and askbot_settings.WIKI_ON,
@@ -532,6 +532,16 @@ def question(request, id):#refactor - long subroutine. display question body, an
         request.user.is_authenticated() and request.user.can_post_comment()
     )
 
+    user_already_gave_answer = False
+    previous_answer = None
+    if request.user.is_authenticated():
+        if askbot_settings.LIMIT_ONE_ANSWER_PER_USER:
+            for answer in answers:
+                if answer.author == request.user:
+                    user_already_gave_answer = True
+                    previous_answer = answer
+                    break
+
     data = {
         'is_cacheable': False,#is_cacheable, #temporary, until invalidation fix
         'long_time': const.LONG_TIME,#"forever" caching
@@ -545,6 +555,8 @@ def question(request, id):#refactor - long subroutine. display question body, an
         'user_votes': user_votes,
         'user_post_id_list': user_post_id_list,
         'user_can_post_comment': user_can_post_comment,#in general
+        'user_already_gave_answer': user_already_gave_answer,
+        'previous_answer': previous_answer,
         'tab_id' : answer_sort_method,
         'favorited' : favorited,
         'similar_threads' : thread.get_similar_threads(),
diff --git a/askbot/views/writers.py b/askbot/views/writers.py
index 232dbaea..9a2de128 100644
--- a/askbot/views/writers.py
+++ b/askbot/views/writers.py
@@ -24,6 +24,7 @@ from django.core import exceptions
 from django.conf import settings
 from django.views.decorators import csrf
 
+from askbot import exceptions as askbot_exceptions
 from askbot import forms
 from askbot import models
 from askbot.skins.loaders import render_into_skin
@@ -499,6 +500,10 @@ def answer(request, id):#process a new answer
                                         timestamp = update_time,
                                     )
                     return HttpResponseRedirect(answer.get_absolute_url())
+                except askbot_exceptions.AnswerAlreadyGiven, e:
+                    request.user.message_set.create(message = unicode(e))
+                    answer = question.thread.get_answers_by_user(request.user)[0]
+                    return HttpResponseRedirect(answer.get_absolute_url())
                 except exceptions.PermissionDenied, e:
                     request.user.message_set.create(message = unicode(e))
             else: