Fix indentation for nested block

IPython/core/inputtransformer2.py

@@ -655,7 +655,15 b' class TransformerManager:'
         if len(tokens_by_line) == 1 and not tokens_by_line[-1]:
             return 'incomplete', 0
 
-        if tokens_by_line[-1][-1].string == ':':
+        new_block = False
+        for token in reversed(tokens_by_line[-1]):
+            if token.type == tokenize.DEDENT:
+                continue
+            elif token.string == ':':
+                new_block = True
+            break
+
+        if new_block:
             # The last line starts a block (e.g. 'if foo:')
             ix = 0
             while tokens_by_line[-1][ix].type in {tokenize.INDENT, tokenize.DEDENT}:

IPython/core/tests/test_inputtransformer2.py

@@ -207,6 +207,7 b' def test_check_complete():'
     cc = ipt2.TransformerManager().check_complete
     nt.assert_equal(cc("a = 1"), ('complete', None))
     nt.assert_equal(cc("for a in range(5):"), ('incomplete', 4))
+    nt.assert_equal(cc("for a in range(5):\n    if a > 0:"), ('incomplete', 8))
     nt.assert_equal(cc("raise = 2"), ('invalid', None))
     nt.assert_equal(cc("a = [1,\n2,"), ('incomplete', 0))
     nt.assert_equal(cc(")"), ('incomplete', 0))