Fix traceback handling of SyntaxErrors without linenos.

IPython/core/tests/test_ultratb.py

@@ -93,3 +93,9 b' class IndentationErrorTest(unittest.TestCase):'
             with tt.AssertPrints("IndentationError"):
                 with tt.AssertPrints("zoon()", suppress=False):
                     ip.magic('run %s' % fname)
+
+class SyntaxErrorTest(unittest.TestCase):
+    def test_syntaxerror_without_lineno(self):
+        with tt.AssertNotPrints("TypeError"):
+            with tt.AssertPrints("line unknown"):
+                ip.run_cell("raise SyntaxError()")

IPython/core/ultratb.py

@@ -556,7 +556,8 b' class ListTB(TBTools):'
                 have_filedata = True
                 #print 'filename is',filename  # dbg
                 if not value.filename: value.filename = "<string>"
-                list.append('%s  File %s"%s"%s, line %s%d%s\n' % \
+                if not value.lineno: value.lineno = "unknown"
+                list.append('%s  File %s"%s"%s, line %s%s%s\n' % \
                         (Colors.normalEm,
                          Colors.filenameEm, py3compat.cast_unicode(value.filename), Colors.normalEm,
                          Colors.linenoEm, value.lineno, Colors.Normal  ))