Fix SVG to PNG conversion when a xlink:href uses a URL

Transform the URL into Data URI in order to avoid ImageMagick and
rsvg-convert limitations. This API should be dropped as soon those external
tools can handle remote URLs (ie.: http, https ...) into SVG definitions.

It was included defensive code and a lot of tests to prevent unexpected
outcomes, like raise ConversionError if the download failures and do
not parse empty content.

product/ERP5/Document/Image.py

@@ -51,6 +51,8 @@ from OFS.Image import Image as OFSImage
 from OFS.Image import getImageInfo
 from zLOG import LOG, WARNING
 
+from Products.ERP5Type.ImageUtil import transformUrlToDataURI
+
 # import mixin
 from Products.ERP5.mixin.text_convertable import TextConvertableMixin
 
@@ -330,6 +332,10 @@ class Image(TextConvertableMixin, File, OFSImage):
     else:
       parameter_list.append('-')
 
+    data = str(self.getData())
+    if self.getContentType() == "image/svg+xml":
+      data = transformUrlToDataURI(data)
+
     process = subprocess.Popen(parameter_list,
                                stdin=subprocess.PIPE,
                                stdout=subprocess.PIPE,
@@ -338,7 +344,7 @@ class Image(TextConvertableMixin, File, OFSImage):
     try:
         # XXX: The only portable way is to pass what stdin.write can accept,
         #      which is a string for PIPE.
-        image, err = process.communicate(str(self.getData()))
+        image, err = process.communicate(data)
     finally:
         del process
     if image:

product/ERP5/tests/testERP5WebWithDms.py

@@ -39,6 +39,7 @@ from Testing import ZopeTestCase
 from Products.ERP5Type.tests.ERP5TypeTestCase import ERP5TypeTestCase,\
      _getConversionServerDict
 from Products.ERP5Type.tests.utils import FileUpload, createZODBPythonScript
+from Products.ERP5.Document.Document import ConversionError
 
 try:
   from PIL import Image
@@ -820,7 +821,7 @@ return True
     module = portal.getDefaultModule(portal_type=portal_type)
     upload_file = makeFileUpload('user-TESTSVG-CASE-FULLURL-TEMPLATE.svg')
     svg_content = upload_file.read().replace("REPLACE_THE_URL_HERE",
-                           makeFilePath("user-TESTSVG-BACKGROUND-IMAGE.png"))
+                           "file://" + makeFilePath("user-TESTSVG-BACKGROUND-IMAGE.png"))
 
     # Add image using data instead file this time as it is not the goal of
     # This test assert this topic.
@@ -843,6 +844,69 @@ return True
       "Conversion from svg to png create one too small image, " + \
       "so it failed to download the image. (%s >= 100)" % difference_value)
 
+  def _testImageConversionFromSVGToPNG_broken_url(self, portal_type="Image"):
+    """ Test Convert one broken SVG into PNG. The expected outcome is a
+        conversion error when an SVG contains one unreacheble xlink:href like.
+        at the url of the image tag. ie:
+         <image xlink:href="http://soidjsoidjqsoijdqsoidjqsdoijsqd.idjsijds/../user-XXX-XXX"
+
+        This is not used by ERP5 in production, but this is way that
+        prooves that conversion from SVG to PNG can use external images.
+    """
+    portal = self.portal
+    module = portal.getDefaultModule(portal_type=portal_type)
+    upload_file = makeFileUpload('user-TESTSVG-CASE-FULLURL-TEMPLATE.svg')
+    svg_content = upload_file.read().replace("REPLACE_THE_URL_HERE",
+                           "http://soidjsoidjqsoijdqsoidjqsdoijsqd.idjsijds/../user-XXX-XXX")
+
+    upload_file = makeFileUpload('user-TESTSVG-CASE-FULLURL-TEMPLATE.svg')
+    svg2_content = upload_file.read().replace("REPLACE_THE_URL_HERE",
+                           "https://www.erp5.com/usXXX-XXX")
+
+
+    # Add image using data instead file this time as it is not the goal of
+    # This test assert this topic.
+    image = module.newContent(portal_type=portal_type,
+                                    data=svg_content,
+                                    filename=upload_file.filename,
+                                    content_type="image/svg+xml",
+                                    reference="NXD-DOCYMENT")
+    # Add image using data instead file this time as it is not the goal of
+    # This test assert this topic.
+    image2 = module.newContent(portal_type=portal_type,
+                                    data=svg2_content,
+                                    filename=upload_file.filename,
+                                    content_type="image/svg+xml",
+                                    reference="NXD-DOCYMENT2")
+
+    image.publish()
+    image2.publish()
+    transaction.commit()
+    self.tic()
+    self.assertEquals(image.getContentType(), 'image/svg+xml')
+    self.assertEquals(image2.getContentType(), 'image/svg+xml')
+    self.assertRaises(ConversionError, image.convert, "png")
+    self.assertRaises(ConversionError, image2.convert, "png")
+
+  def _testImageConversionFromSVGToPNG_empty_file(self, portal_type="Image"):
+    """ Test Convert one empty SVG into PNG. The expected outcome is ???
+    """
+    portal = self.portal
+    module = portal.getDefaultModule(portal_type=portal_type)
+
+
+    # Add image using data instead file this time as it is not the goal of
+    # This test assert this topic.
+    image = module.newContent(portal_type=portal_type,
+                                    content_type="image/svg+xml",
+                                    reference="NXD-DOCYMENT")
+
+    image.publish()
+    transaction.commit()
+    self.tic()
+    self.assertEquals(image.getContentType(), 'image/svg+xml')
+    self.assertRaises(ConversionError, image.convert, "png")
+
   def test_ImageConversionFromSVGToPNG_embeeded_data(self):
     """ Test Convert one SVG Image with an image with the data
         at the url of the image tag.ie:
@@ -864,6 +928,36 @@ return True
     """
     self._testImageConversionFromSVGToPNG("Web Page")
 
+  def test_ImageConversionFromSVGToPNG_broken_url(self):
+    """ Test Convert one SVG Image with an broken image href
+    """
+    self._testImageConversionFromSVGToPNG_broken_url("Image")
+
+  def test_FileConversionFromSVGToPNG_broken_url(self):
+    """ Test Convert one SVG Image with an broken image href
+    """
+    self._testImageConversionFromSVGToPNG_broken_url("File")
+
+  def test_WebPageConversionFromSVGToPNG_broken_url(self):
+    """ Test Convert one SVG Image with an broken image href
+    """
+    self._testImageConversionFromSVGToPNG_broken_url("Web Page")
+
+  def test_ImageConversionFromSVGToPNG_empty_file(self):
+    """ Test Convert one SVG Image with an empty svg
+    """
+    self._testImageConversionFromSVGToPNG_empty_file("Image")
+
+  def test_FileConversionFromSVGToPNG_empty_file(self):
+    """ Test Convert one SVG Image with an empty svg
+    """
+    self._testImageConversionFromSVGToPNG_empty_file("File")
+
+  def test_WebPageConversionFromSVGToPNG_empty_file(self):
+    """ Test Convert one SVG Image with an empty svg
+    """
+    self._testImageConversionFromSVGToPNG_empty_file("Web Page")
+
   def test_ImageConversionFromSVGToPNG_file_url(self):
     """ Test Convert one SVG Image with an image using local path (file)
         at the url of the image tag. ie:
@@ -918,8 +1012,6 @@ return True
     self._testImageConversionFromSVGToPNG(
           "Web Page", "user-TESTSVG-CASE-FULLURL")
 
-
-
 def test_suite():
   suite = unittest.TestSuite()
   suite.addTest(unittest.makeSuite(TestERP5WebWithDms))

product/ERP5/tests/test_data/user-TESTSVG-CASE-FULLURL-TEMPLATE.svg

@@ -54,7 +54,7 @@
      y="0.99838382"
      x="0.11206181"
      id="image3065"
-     xlink:href="file://REPLACE_THE_URL_HERE"
+     xlink:href="REPLACE_THE_URL_HERE"
      height="369.32098"
      width="523.56" />
   <rect

product/ERP5Type/ImageUtil.py

+#############################################################################
+#
+# Copyright (c) 2011 Nexedi SA and Contributors. All Rights Reserved.
+#                    Rafael Monnerat <rafael@nexedi.com>
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsability of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# garantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+##############################################################################
+
+import urllib2
+from lxml import etree
+from Products.ERP5.Document.Document import ConversionError
+
+def getDataURI(url):
+  try:
+    data = urllib2.urlopen(url)
+  except Exception, e:
+    raise ConversionError("Error to transform url (%s) into data uri. ERROR = %s" % (url, Exception(e)))
+  return 'data:%s;base64,%s' % (data.info()["content-type"],
+                                data.read().encode("base64").replace('\n', ""))
+
+def transformUrlToDataURI(content):
+  if content is None or len(content) == 0:
+    return content
+
+  root = etree.fromstring(content)
+
+  # Prevent namespace contains "None" included into svg by mistake
+  namespace_dict = root.nsmap.copy()
+  namespace_dict.pop(None, "discard")
+
+  # Get all images which uses xlink:href
+  image_list = root.xpath("//svg:image[@xlink:href]", namespaces=namespace_dict)
+  xlink_href = "{%s}href" % namespace_dict.get("xlink", None)
+  # Transform all images which uses url, into data URI
+  for image in image_list:
+    url_value = image.get(xlink_href)
+    if url_value.startswith("http"):
+      image.set(xlink_href, getDataURI(image.get(xlink_href)))
+
+  return """<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n""" + \
+         etree.tostring(root)
+

product/ERP5Type/ZopePatch.py

@@ -72,6 +72,7 @@ from Products.ERP5Type.patches import OFSItem
 from Products.ERP5Type.patches import ExternalMethod
 from Products.ERP5Type.patches import User
 from Products.ERP5Type.patches import zopecontenttype
+from Products.ERP5Type.patches import OFSImage
 
 # These symbols are required for backward compatibility
 from Products.ERP5Type.patches.PropertyManager import ERP5PropertyManager

product/ERP5Type/patches/OFSImage.py

+##############################################################################
+#
+# Copyright (c) 2002 Zope Foundation and Contributors.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE
+#
+##############################################################################
+"""
+  Monkey-patch to fix OFS.Image, which is not capable to detect the SVG 
+  Content Type format. 
+
+  Monkey patch uses 2.12.3 original code.
+"""
+import OFS.Image
+import struct
+from cStringIO import StringIO
+
+def getImageInfo_with_svg_fix(data):
+    data = str(data)
+    size = len(data)
+    height = -1
+    width = -1
+    content_type = ''
+
+    # handle GIFs
+    if (size >= 10) and data[:6] in ('GIF87a', 'GIF89a'):
+        # Check to see if content_type is correct
+        content_type = 'image/gif'
+        w, h = struct.unpack("<HH", data[6:10])
+        width = int(w)
+        height = int(h)
+
+    # See PNG v1.2 spec (http://www.cdrom.com/pub/png/spec/)
+    # Bytes 0-7 are below, 4-byte chunk length, then 'IHDR'
+    # and finally the 4-byte width, height
+    elif ((size >= 24) and (data[:8] == '\211PNG\r\n\032\n')
+          and (data[12:16] == 'IHDR')):
+        content_type = 'image/png'
+        w, h = struct.unpack(">LL", data[16:24])
+        width = int(w)
+        height = int(h)
+
+    # Maybe this is for an older PNG version.
+    elif (size >= 16) and (data[:8] == '\211PNG\r\n\032\n'):
+        # Check to see if we have the right content type
+        content_type = 'image/png'
+        w, h = struct.unpack(">LL", data[8:16])
+        width = int(w)
+        height = int(h)
+
+    # handle JPEGs
+    elif (size >= 2) and (data[:2] == '\377\330'):
+        content_type = 'image/jpeg'
+        jpeg = StringIO(data)
+        jpeg.read(2)
+        b = jpeg.read(1)
+        try:
+            while (b and ord(b) != 0xDA):
+                while (ord(b) != 0xFF): b = jpeg.read(1)
+                while (ord(b) == 0xFF): b = jpeg.read(1)
+                if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
+                    jpeg.read(3)
+                    h, w = struct.unpack(">HH", jpeg.read(4))
+                    break
+                else:
+                    jpeg.read(int(struct.unpack(">H", jpeg.read(2))[0])-2)
+                b = jpeg.read(1)
+            width = int(w)
+            height = int(h)
+        except: pass
+
+    # MONKEY PATCH START HERE
+    # Handle SVG
+    elif ("</svg>" in data):
+        content_type = 'image/svg+xml'
+    # MONKEY PATCH ENDS HERE
+
+    return content_type, width, height
+
+OFS.Image.getImageInfo = getImageInfo_with_svg_fix