From 9620cc04634e720d1d016cce4bf02e0c27607e64 Mon Sep 17 00:00:00 2001
From: Benjamin Peterson <benjamin@python.org>
Date: Sat, 11 Jun 2011 15:53:11 -0500
Subject: [PATCH] allow "fake" filenames in findsource (closes #9284)

This allows findsource() to work in doctests.

A patch from Dirkjan Ochtman.
---
 Lib/inspect.py           |  8 ++++++--
 Lib/test/test_inspect.py | 17 +++++++++++++++++
 Misc/NEWS                |  3 +++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/Lib/inspect.py b/Lib/inspect.py
index 4899cbf9f0..bb46ea6f85 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -518,9 +518,13 @@ def findsource(object):
     or code object.  The source code is returned as a list of all the lines
     in the file and the line number indexes a line in that list.  An IOError
     is raised if the source code cannot be retrieved."""
-    file = getsourcefile(object)
-    if not file:
+
+    file = getfile(object)
+    sourcefile = getsourcefile(object)
+    if not sourcefile and file[0] + file[-1] != '<>':
         raise IOError('source code not available')
+    file = sourcefile if sourcefile else file
+
     module = getmodule(object, file)
     if module:
         lines = linecache.getlines(file, module.__dict__)
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index f5dff1e543..7666fe43a7 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -298,6 +298,23 @@ class TestRetrievingSourceCode(GetSourceBase):
         del sys.modules[name]
         inspect.getmodule(compile('a=10','','single'))
 
+    def test_proceed_with_fake_filename(self):
+        '''doctest monkeypatches linecache to enable inspection'''
+        fn, source = '<test>', 'def x(): pass\n'
+        getlines = linecache.getlines
+        def monkey(filename, module_globals=None):
+            if filename == fn:
+                return source.splitlines(True)
+            else:
+                return getlines(filename, module_globals)
+        linecache.getlines = monkey
+        try:
+            ns = {}
+            exec(compile(source, fn, 'single'), ns)
+            inspect.getsource(ns["x"])
+        finally:
+            linecache.getlines = getlines
+
 class TestDecorators(GetSourceBase):
     fodderModule = mod2
 
diff --git a/Misc/NEWS b/Misc/NEWS
index d3496b0f2d..de1c531025 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -22,6 +22,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #9284: Allow inspect.findsource() to find the source of doctest
+  functions.
+
 - Issue #12009: Fixed regression in netrc file comment handling.
 
 - Issue #10694: zipfile now ignores garbage at the end of a zipfile.
-- 
2.40.0