graphviz: also catch IOError with Errno 22 (invalid parameter)

This happen on Python2.7 and Graphviz version 2.12 (Mon Dec  4 22:04:37 UTC 2006)
on Windows when a not recognized renderer type is asked.

sphinx/ext/graphviz.py

@@ -25,7 +25,7 @@ from docutils import nodes
 from docutils.parsers.rst import directives
 
 from sphinx.errors import SphinxError
-from sphinx.util.osutil import ensuredir, ENOENT, EPIPE
+from sphinx.util.osutil import ensuredir, ENOENT, EPIPE, EINVAL
 from sphinx.util.compat import Directive
 
 
@@ -163,6 +163,7 @@ def render_dot(self, code, options, format, prefix='graphviz'):
                           self.builder.config.graphviz_dot)
         self.builder._graphviz_warned_dot = True
         return None, None
+    wentWrong = False
     try:
         # Graphviz may close standard input when an error occurs,
         # resulting in a broken pipe on communicate()
@@ -170,6 +171,12 @@ def render_dot(self, code, options, format, prefix='graphviz'):
     except OSError, err:
         if err.errno != EPIPE:
             raise
+        wentWrong = True
+    except IOError, err:
+        if err.errno != EINVAL:
+            raise
+        wentWrong = True
+    if wentWrong:
         # in this case, read the standard output and standard error streams
         # directly, to get the error message(s)
         stdout, stderr = p.stdout.read(), p.stderr.read()

sphinx/util/osutil.py

@@ -21,6 +21,7 @@ from os import path
 EEXIST = getattr(errno, 'EEXIST', 0)
 ENOENT = getattr(errno, 'ENOENT', 0)
 EPIPE  = getattr(errno, 'EPIPE', 0)
+EINVAL = getattr(errno, 'EINVAL', 0)
 
 # SEP separates path elements in the canonical file names
 #