Issue #12323: Strengthen error checking of the position XPath selectors

This commit is contained in:
Eli Bendersky 2013-01-24 06:29:26 -08:00
parent 7ff241d830
commit 5c6198b3fd
2 changed files with 12 additions and 2 deletions

View File

@ -1793,6 +1793,11 @@ class ElementFindTest(unittest.TestCase):
self.assertEqual(e.find('./tag[last()-1]').attrib['class'], 'c')
self.assertEqual(e.find('./tag[last()-2]').attrib['class'], 'b')
self.assertRaisesRegex(SyntaxError, 'XPath', e.find, './tag[0]')
self.assertRaisesRegex(SyntaxError, 'XPath', e.find, './tag[-1]')
self.assertRaisesRegex(SyntaxError, 'XPath', e.find, './tag[last()-0]')
self.assertRaisesRegex(SyntaxError, 'XPath', e.find, './tag[last()+1]')
def test_findall(self):
e = ET.XML(SAMPLE_XML)
e[2] = ET.XML(SAMPLE_SECTION)

View File

@ -174,7 +174,7 @@ def prepare_predicate(next, token):
if elem.get(key) == value:
yield elem
return select
if signature == "-" and not re.match("\d+$", predicate[0]):
if signature == "-" and not re.match("\-?\d+$", predicate[0]):
# [tag]
tag = predicate[0]
def select(context, result):
@ -182,7 +182,7 @@ def prepare_predicate(next, token):
if elem.find(tag) is not None:
yield elem
return select
if signature == "-='" and not re.match("\d+$", predicate[0]):
if signature == "-='" and not re.match("\-?\d+$", predicate[0]):
# [tag='value']
tag = predicate[0]
value = predicate[-1]
@ -196,7 +196,10 @@ def prepare_predicate(next, token):
if signature == "-" or signature == "-()" or signature == "-()-":
# [index] or [last()] or [last()-index]
if signature == "-":
# [index]
index = int(predicate[0]) - 1
if index < 0:
raise SyntaxError("XPath position >= 1 expected")
else:
if predicate[0] != "last":
raise SyntaxError("unsupported function")
@ -205,6 +208,8 @@ def prepare_predicate(next, token):
index = int(predicate[2]) - 1
except ValueError:
raise SyntaxError("unsupported expression")
if index > -2:
raise SyntaxError("XPath offset from last() must be negative")
else:
index = -1
def select(context, result):