Merge pull request #5442 from affanv14/bugfix

theano/compile/function_module.py

@@ -749,6 +749,12 @@ class Function(object):
             List of outputs on indices/keys from ``output_subset`` or all of them,
             if ``output_subset`` is not passed.
         """
+        def restore_defaults():
+            for i, (required, refeed, value) in enumerate(self.defaults):
+                if refeed:
+                    if isinstance(value, gof.Container):
+                        value = value.storage[0]
+                    self[i] = value
         profile = self.profile
         t0 = time.time()
 
@@ -804,6 +810,7 @@ class Function(object):
                             e.args = ("Bad input " + argument_name + " to " +
                                       function_name + " at index %d (0-based). %s"
                                       % (i, where),) + e.args
+                        restore_defaults()
                         raise
                 s.provided += 1
                 i += 1
@@ -853,14 +860,17 @@ class Function(object):
         if not self.trust_input:
             for c in self.input_storage:
                 if c.required and not c.provided:
+                    restore_defaults()
                     raise TypeError("Missing required input: %s" %
                                     getattr(self.inv_finder[c], 'variable',
                                             self.inv_finder[c]))
                 if c.provided > 1:
+                    restore_defaults()
                     raise TypeError("Multiple values for input: %s" %
                                     getattr(self.inv_finder[c], 'variable',
                                             self.inv_finder[c]))
                 if c.implicit and c.provided > 0:
+                    restore_defaults()
                     raise TypeError(
                         'Tried to provide value for implicit input: %s'
                         % getattr(self.inv_finder[c], 'variable',
@@ -873,6 +883,7 @@ class Function(object):
                 self.fn() if output_subset is None else\
                 self.fn(output_subset=output_subset)
         except Exception:
+            restore_defaults()
             if hasattr(self.fn, 'position_of_error'):
                 # this is a new vm-provided function or c linker
                 # they need this because the exception manipulation
@@ -925,11 +936,7 @@ class Function(object):
             outputs = outputs[:self.n_returned_outputs]
 
         # Put default values back in the storage
-        for i, (required, refeed, value) in enumerate(self.defaults):
-            if refeed:
-                if isinstance(value, gof.Container):
-                    value = value.storage[0]
-                self[i] = value
+        restore_defaults()
         #
         # NOTE: This logic needs to be replicated in
         #       scan.

theano/compile/tests/test_function_module.py

@@ -579,6 +579,20 @@ class T_function(unittest.TestCase):
             if not isinstance(key, theano.gof.Constant):
                 assert (val[0] is None)
 
+    def test_default_values(self):
+        """
+        Check that default values are restored
+        when an exception occurs in interactive mode.
+        """
+        a, b = T.dscalars('a', 'b')
+        c = a + b
+        func = theano.function([theano.In(a, name='first'), theano.In(b, value=1, name='second')], c)
+        x = func(first=1)
+        try:
+            func(second=2)
+        except TypeError:
+            assert(func(first=1) == x)
+
 
 class T_picklefunction(unittest.TestCase):