Add IPython support for Cython functions

build/pkgs/ipython/package-version.txt

@@ -1 +1 @@
-5.5.0
+5.5.0.p0

build/pkgs/ipython/patches/signature.patch

@@ -0,0 +1,47 @@
+See https://github.com/ipython/ipython/pull/11139
+
+commit 98e7ddd43bab127de68a3c66870b8e17a5b50eeb
+Author: Jeroen Demeyer <jdemeyer@cage.ugent.be>
+Date:   Wed May 16 14:32:15 2018 +0200
+
+    Use inspect instead of type checks
+
+diff --git a/IPython/utils/_signatures.py b/IPython/utils/_signatures.py
+index 3b53e89..20f52b9 100644
+--- a/IPython/utils/_signatures.py
++++ b/IPython/utils/_signatures.py
+@@ -21,6 +21,7 @@
+ import functools
+ import re
+ import types
++import inspect
+
+
+ # patch for single-file
+@@ -71,7 +72,7 @@ def signature(obj):
+     if not callable(obj):
+         raise TypeError('{0!r} is not a callable object'.format(obj))
+
+-    if isinstance(obj, types.MethodType):
++    if inspect.ismethod(obj):
+         if obj.__self__ is None:
+             # Unbound method - treat it as a function (no distinction in Py 3)
+             obj = obj.__func__
+@@ -96,7 +97,7 @@ def signature(obj):
+     else:
+         return signature(wrapped)
+
+-    if isinstance(obj, types.FunctionType):
++    if inspect.isfunction(obj):
+         return Signature.from_function(obj)
+
+     if isinstance(obj, functools.partial):
+@@ -511,7 +512,7 @@ def __init__(self, parameters=None, return_annotation=_empty,
+     def from_function(cls, func):
+         '''Constructs Signature for the given python function'''
+
+-        if not isinstance(func, types.FunctionType):
++        if not inspect.isfunction(func):
+             raise TypeError('{0!r} is not a Python function'.format(func))
+
+         Parameter = cls._parameter_cls

src/sage/__init__.py

@@ -39,6 +39,14 @@ def isfunction(obj):
         False
         sage: isfunction(Integer(1).digits)  # bound method
         False
+
+    Verify that ipywidgets can correctly determine signatures of Cython
+    functions::
+
+        sage: from ipywidgets.widgets.interaction import signature
+        sage: from sage.dynamics.complex_dynamics.mandel_julia_helper import fast_mandelbrot_plot
+        sage: signature(fast_mandelbrot_plot)  # random
+        <IPython.utils._signatures.Signature object at 0x7f3ec8274e10>
     """
     # We use type(obj) instead of just obj to avoid __getattr__().
     # Some types, like methods, will return the __code__ of the

src/sage/dynamics/complex_dynamics/mandel_julia_helper.pyx

@@ -1,3 +1,4 @@
+# cython: binding=True
 r"""
 Mandelbrot and Julia sets (Cython helper)