#17526: merge with 3.3.

Lib/inspect.py

@@ -550,7 +550,7 @@ 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 OSError('source code not available')
     file = sourcefile if sourcefile else file
 

Lib/test/test_inspect.py

@@ -416,6 +416,12 @@ class TestBuggyCases(GetSourceBase):
         finally:
             del linecache.cache[co.co_filename]
 
+    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 TestNoEOL(GetSourceBase):
     def __init__(self, *args, **kwargs):
         self.tempdir = TESTFN + '_dir'

Misc/NEWS

@@ -297,6 +297,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #17526: fix an IndexError raised while passing code without filename to
+  inspect.findsource().  Initial patch by Tyler Doyle.
+
 - Issue #17540: Added style to formatter configuration by dict.
 
 - Issue #16692: The ssl module now supports TLS 1.1 and TLS 1.2.  Initial