new file mode 100644

@@ -0,0 +1,3 @@

+digraph {

+   1 [label="a\\00"]

+}

new file mode 100644

@@ -0,0 +1,3 @@

+digraph {

+   1 [label="a\\b"]

+}

@@ -14,8 +14,11 @@

 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

 #

 import colorsys

+import re

 import sys

+from distutils.version import LooseVersion

+

 from .lexer import ParseError, DotLexer

 from ..ui.colors import lookup_color

@@ -85,7 +88,14 @@ class XDotAttrParser:

     - http://www.graphviz.org/doc/info/output.html#d:xdot

     """

-    def __init__(self, parser, buf):

+    def __init__(self, parser, buf, broken_backslashes):

+

+        # `\` should be escaped as `\\`, but older versions of graphviz xdot

+        # output failed to properly escape it.  See also

+        # https://github.com/jrfonseca/xdot.py/issues/92

+        if not broken_backslashes:

+            buf = re.sub(br'\\(.)', br'\1', buf)

+

         self.parser = parser

         self.buf = buf

         self.pos = 0

@@ -427,10 +437,16 @@ class XDotParser(DotParser):

     XDOTVERSION = '1.7'

-    def __init__(self, xdotcode):

+    def __init__(self, xdotcode, graphviz_version=None):

         lexer = DotLexer(buf=xdotcode)

         DotParser.__init__(self, lexer)

+        # https://github.com/jrfonseca/xdot.py/issues/92

+        self.broken_backslashes = False

+        if graphviz_version is not None and \

+                LooseVersion(graphviz_version) < LooseVersion("2.46.0"):

+            self.broken_backslashes = True

+

         self.nodes = []

         self.edges = []

         self.shapes = []

@@ -480,7 +496,7 @@ class XDotParser(DotParser):

         for attr in ("_draw_", "_ldraw_", "_hdraw_", "_tdraw_", "_hldraw_", "_tldraw_"):

             if attr in attrs:

-                parser = XDotAttrParser(self, attrs[attr])

+                parser = XDotAttrParser(self, attrs[attr], self.broken_backslashes)

                 self.shapes.extend(parser.parse())

     def handle_node(self, id, attrs):

@@ -502,7 +518,7 @@ class XDotParser(DotParser):

         shapes = []

         for attr in ("_draw_", "_ldraw_"):

             if attr in attrs:

-                parser = XDotAttrParser(self, attrs[attr])

+                parser = XDotAttrParser(self, attrs[attr], self.broken_backslashes)

                 shapes.extend(parser.parse())

         try:

             url = attrs['URL']

@@ -525,7 +541,7 @@ class XDotParser(DotParser):

         shapes = []

         for attr in ("_draw_", "_ldraw_", "_hdraw_", "_tdraw_", "_hldraw_", "_tldraw_"):

             if attr in attrs:

-                parser = XDotAttrParser(self, attrs[attr])

+                parser = XDotAttrParser(self, attrs[attr], self.broken_backslashes)

                 shapes.extend(parser.parse())

         if shapes:

             src = self.node_by_name[src_id]

@@ -56,6 +56,7 @@ class DotWidget(Gtk.DrawingArea):

     }

     filter = 'dot'

+    graphviz_version = None

     def __init__(self):

         Gtk.DrawingArea.__init__(self)

@@ -100,6 +101,7 @@ class DotWidget(Gtk.DrawingArea):

     def set_filter(self, filter):

         self.filter = filter

+        self.graphviz_version = None

     def run_filter(self, dotcode):

         if not self.filter:

@@ -153,7 +155,14 @@ class DotWidget(Gtk.DrawingArea):

     def set_xdotcode(self, xdotcode, center=True):

         assert isinstance(xdotcode, bytes)

-        parser = XDotParser(xdotcode)

+        if self.graphviz_version is None:

+            stdout = subprocess.check_output([self.filter, '-V'], stderr=subprocess.STDOUT)

+            stdout = stdout.rstrip()

+            mo = re.match(br'^.* - .* version (?P<version>.*) \(.*\)$', stdout)

+            assert mo

+            self.graphviz_version = mo.group('version').decode('ascii')

+

+        parser = XDotParser(xdotcode, graphviz_version=self.graphviz_version)

         self.graph = parser.parse()

         self.zoom_image(self.zoom_ratio, center=center)