[2.7] bpo-6700: Fix inspect.getsourcelines for module level frames/tracebacks (GH-8864)

(cherry picked from commit 91cb298f811961277fd4cc4a32211899d48bedcb)

Co-authored-by: Vladimir Matveev <v2matveev@outlook.com>

3 files changed, 28 insertions, 4 deletions

diff --git a/Lib/inspect.py b/Lib/inspect.py
index 0a6cfd7951..cbced17373 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -688,8 +688,15 @@ def getsourcelines(object):
     raised if the source code cannot be retrieved."""
     lines, lnum = findsource(object)
 
-    if ismodule(object): return lines, 0
-    else: return getblock(lines[lnum:]), lnum + 1
+    if istraceback(object):
+        object = object.tb_frame
+
+    # for module or frame that corresponds to module, return all source lines
+    if (ismodule(object) or
+        (isframe(object) and object.f_code.co_name == "<module>")):
+        return lines, 0
+    else:
+        return getblock(lines[lnum:]), lnum + 1
 
 def getsource(object):
     """Return the text of the source code for an object.
diff --git a/Lib/test/inspect_fodder.py b/Lib/test/inspect_fodder.py
index 5c87ae6f82..548765c797 100644
--- a/Lib/test/inspect_fodder.py
+++ b/Lib/test/inspect_fodder.py
@@ -56,3 +56,9 @@ class ParrotDroppings:
 
 class FesteringGob(MalodorousPervert, ParrotDroppings):
     pass
+
+currentframe = inspect.currentframe()
+try:
+    raise Exception()
+except:
+    tb = sys.exc_info()[2]
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 7d09c6fa02..5063a30d22 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -209,7 +209,7 @@ class GetSourceBase(unittest.TestCase):
 
     def sourcerange(self, top, bottom):
         lines = self.source.split("\n")
-        return "\n".join(lines[top-1:bottom]) + "\n"
+        return "\n".join(lines[top-1:bottom]) + ("\n" if bottom else "")
 
     def assertSourceEqual(self, obj, top, bottom):
         self.assertEqual(inspect.getsource(obj),
@@ -331,6 +331,16 @@ class TestRetrievingSourceCode(GetSourceBase):
         finally:
             linecache.getlines = getlines
 
+class TestGettingSourceOfToplevelFrames(GetSourceBase):
+    fodderFile = mod
+
+    def test_range_toplevel_frame(self):
+        self.maxDiff = None
+        self.assertSourceEqual(mod.currentframe, 1, None)
+
+    def test_range_traceback_toplevel_frame(self):
+        self.assertSourceEqual(mod.tb, 1, None)
+
 class TestDecorators(GetSourceBase):
     fodderFile = mod2
 
@@ -896,7 +906,8 @@ def test_main():
         TestDecorators, TestRetrievingSourceCode, TestOneliners, TestBuggyCases,
         TestInterpreterStack, TestClassesAndFunctions, TestPredicates,
         TestGetcallargsFunctions, TestGetcallargsFunctionsCellVars,
-        TestGetcallargsMethods, TestGetcallargsUnboundMethods)
+        TestGetcallargsMethods, TestGetcallargsUnboundMethods,
+        TestGettingSourceOfToplevelFrames)
 
 if __name__ == "__main__":
     test_main()