Fix Issue 479669: Handle empty styl elements

scour.py

@@ -420,12 +420,12 @@ def findReferencedElements(node, ids=None):
 	# if this node is a style element, parse its text into CSS
 	if node.nodeName == 'style' and node.namespaceURI == NS['SVG']:
 		# node.firstChild will be either a CDATA or a Text node
-		cssRules = parseCssString(node.firstChild.nodeValue)
+		if node.firstChild != None:
-		for rule in cssRules:
+			cssRules = parseCssString(node.firstChild.nodeValue)
-			for propname in rule['properties']:
+			for rule in cssRules:
-				propval = rule['properties'][propname]
+				for propname in rule['properties']:
-				findReferencingProperty(node, propname, propval, ids)
+					propval = rule['properties'][propname]
-		
+					findReferencingProperty(node, propname, propval, ids)
 		return ids
 	
 	# else if xlink:href is set, then grab the id

testscour.py

@@ -957,6 +957,16 @@ class EnsurePreserveWhitespaceOnNonTextElements(unittest.TestCase):
 		self.assertEquals( s.count('\n'), 5,
 			'Did not properly preserve whitespace on elements even if they were not textual')
 
+class HandleEmptyStyleElement(unittest.TestCase):
+	def runTest(self):
+		try:
+			styles = scour.scourXmlFile('unittests/empty-style.svg').getElementsByTagNameNS(SVGNS, 'style')
+			fail = len(styles) != 1
+		except AttributeError:
+			fail = True
+		self.assertEquals( fail, False,
+			'Could not handle an empty style element')
+
 # TODO; write a test for embedding rasters
 # TODO: write a test for --disable-embed-rasters
 # TODO: write tests for --keep-editor-data

unittests/empty-style.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" ?>
+<svg xmlns="http://www.w3.org/2000/svg">
+    <style id="style1" />
+</svg>