Fixed #3300 -- Changed newforms Select widget to collapse 'choices' into a list if it's an iterable, so the iterable can be iterated over multiple times.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4435 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 24 insertions, 2 deletions

diff --git a/django/newforms/widgets.py b/django/newforms/widgets.py
index c71810465e..3c27f7e2c1 100644
--- a/django/newforms/widgets.py
+++ b/django/newforms/widgets.py
@@ -136,9 +136,11 @@ class CheckboxInput(Widget):
 
 class Select(Widget):
     def __init__(self, attrs=None, choices=()):
-        # choices can be any iterable
         self.attrs = attrs or {}
-        self.choices = choices
+        # choices can be any iterable, but we may need to render this widget
+        # multiple times. Thus, collapse it into a list so it can be consumed
+        # more than once.
+        self.choices = list(choices)
 
     def render(self, name, value, attrs=None, choices=()):
         if value is None: value = ''
diff --git a/tests/regressiontests/forms/tests.py b/tests/regressiontests/forms/tests.py
index 95e8b59c01..328582d162 100644
--- a/tests/regressiontests/forms/tests.py
+++ b/tests/regressiontests/forms/tests.py
@@ -336,6 +336,26 @@ If 'choices' is passed to both the constructor and render(), then they'll both b
 >>> w.render('email', 'ŠĐĆŽćžšđ', choices=[('ŠĐĆŽćžšđ', 'ŠĐabcĆŽćžšđ'), ('ćžšđ', 'abcćžšđ')])
 u'<select name="email">\n<option value="1">1</option>\n<option value="2">2</option>\n<option value="3">3</option>\n<option value="\u0160\u0110\u0106\u017d\u0107\u017e\u0161\u0111" selected="selected">\u0160\u0110abc\u0106\u017d\u0107\u017e\u0161\u0111</option>\n<option value="\u0107\u017e\u0161\u0111">abc\u0107\u017e\u0161\u0111</option>\n</select>'
 
+If choices is passed to the constructor and is a generator, it can be iterated
+over multiple times without getting consumed:
+>>> w = Select(choices=get_choices())
+>>> print w.render('num', 2)
+<select name="num">
+<option value="0">0</option>
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+<option value="4">4</option>
+</select>
+>>> print w.render('num', 3)
+<select name="num">
+<option value="0">0</option>
+<option value="1">1</option>
+<option value="2">2</option>
+<option value="3" selected="selected">3</option>
+<option value="4">4</option>
+</select>
+
 # NullBooleanSelect Widget ####################################################
 
 >>> w = NullBooleanSelect()