Merge branch 'public/23496_patch_sympy_abstact_function' of git://tra…

…c.sagemath.org/sage into public/23496_patch_sympy_abstact_function

build/pkgs/sympy/package-version.txt

@@ -1 +1 @@
-1.0.p2
+1.0.p3

build/pkgs/sympy/patches/02_undeffun_sage.patch

@@ -0,0 +1,59 @@
+diff --git a/sympy/core/function.py b/sympy/core/function.py
+index 4c4ce9c..63c52da 100644
+--- a/sympy/core/function.py
++++ b/sympy/core/function.py
+@@ -746,8 +746,21 @@ def _eval_as_leading_term(self, x):
+     def _sage_(self):
+         import sage.all as sage
+         fname = self.func.__name__
+-        func = getattr(sage, fname)
++        func = getattr(sage, fname,None)
+         args = [arg._sage_() for arg in self.args]
++
++        # In the case the function is not known in sage:
++        if func is None:
++            import sympy
++            if getattr(sympy, fname,None) is None:
++                # abstract function
++                return sage.function(fname)(*args)
++
++            else:
++                # the function defined in sympy is not known in sage
++                # this exception is catched in sage
++                raise AttributeError
++
+         return func(*args)
+
+
+diff --git a/sympy/external/tests/test_sage.py b/sympy/external/tests/test_sage.py
+index bc404b6..ed41d42 100644
+--- a/sympy/external/tests/test_sage.py
++++ b/sympy/external/tests/test_sage.py
+@@ -222,6 +222,19 @@ def test_undefined_function():
+     assert bool(sf(sx) == f(x)._sage_())
+     #assert bool(f == sympy.sympify(sf))
+
++def test_abstract_function():
++    from sage.symbolic.expression import Expression
++    x,y = sympy.symbols('x y')
++    f = sympy.Function('f')
++    expr =  f(x,y)
++    sexpr = expr._sage_()
++    assert isinstance(sexpr,Expression), "converted expression %r is not sage expression" % sexpr
++    # This test has to be uncommented in the future: it depends on the sage ticket #22802 (https://trac.sagemath.org/ticket/22802)
++    # invexpr = sexpr._sympy_()
++    # assert invexpr == expr, "inverse coversion %r is not correct " % invexpr
++
++
++
+ # This string contains Sage doctests, that execute all the functions above.
+ # When you add a new function, please add it here as well.
+ """
+@@ -244,6 +257,7 @@ def test_undefined_function():
+     sage: test_issue_4023()
+     sage: test_integral()
+     sage: test_undefined_function()
++    sage  test_abstract_function()
+
+ Sage has no symbolic Lucas function at the moment::
+