#17526: fix an IndexError raised while passing code without filename to inspect.findsource(). Initial patch by Tyler Doyle.

Lib/inspect.py

@@ -525,7 +525,7 @@ def findsource(object):
 
     file = getfile(object)
     sourcefile = getsourcefile(object)
-    if not sourcefile and file[0] + file[-1] != '<>':
+    if not sourcefile and file[:1] + file[-1:] != '<>':
         raise IOError('source code not available')
     file = sourcefile if sourcefile else file
 

Lib/test/test_inspect.py

@@ -404,6 +404,12 @@ class TestBuggyCases(GetSourceBase):
         self.assertEqual(inspect.findsource(co), (lines,0))
         self.assertEqual(inspect.getsource(co), lines[0])
 
+    def test_findsource_without_filename(self):
+        for fname in ['', '<string>']:
+            co = compile('x=1', fname, "exec")
+            self.assertRaises(IOError, inspect.findsource, co)
+            self.assertRaises(IOError, inspect.getsource, co)
+
 
 class _BrokenDataDescriptor(object):
     """

Misc/NEWS

@@ -12,6 +12,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #17526: fix an IndexError raised while passing code without filename to
+  inspect.findsource().  Initial patch by Tyler Doyle.
+
 
 What's New in Python 2.7.4?
 ===========================