pythongh-105013: Fix inspect.getsource with parenthesized multiline lambdas

Author: pablogsal

Lib/inspect.py

@@ -1242,6 +1242,9 @@ def getblock(lines):
             blockfinder.tokeneater(*_token)
     except (EndOfBlock, IndentationError):
         pass
+    except SyntaxError as e:
+        if "unmatched ')" not in e.msg:
+            raise e from None
     return lines[:blockfinder.last]
 
 def getsourcelines(object):

Lib/test/inspect_fodder2.py

@@ -273,3 +273,11 @@ def wrapper(*a, **kwd):
 @deco_factory(foo=(1 + 2), bar=lambda: 1)
 def complex_decorated(foo=0, bar=lambda: 0):
     return foo + bar()
+
+# line 276
+parenthesized_lambda = (
+    lambda: ())
+
+# line 281
+post_line_parenthesized_lambda = (lambda: ()
+)

Lib/test/test_inspect.py

@@ -776,6 +776,16 @@ def test_twoline_indented_lambda(self):
         # where the second line _is_ indented.
         self.assertSourceEqual(mod2.tlli, 33, 34)
 
+    def test_parenthesized_multiline_lambda(self):
+        # Test inspect.getsource with a parenthesized multi-line lambda
+        # function.
+        self.assertSourceEqual(mod2.parenthesized_lambda, 279, 279)
+
+    def test_post_line_parenthesized_lambda(self):
+        # Test inspect.getsource with a parenthesized multi-line lambda
+        # function.
+        self.assertSourceEqual(mod2.post_line_parenthesized_lambda, 282, 283)
+
     def test_onelinefunc(self):
         # Test inspect.getsource with a regular one-line function.
         self.assertSourceEqual(mod2.onelinefunc, 37, 37)

Misc/NEWS.d/next/Core and Builtins/2023-05-27-16-57-11.gh-issue-105013.IsDgDY.rst

@@ -0,0 +1,2 @@
+Fix handling of multiline parenthesized lambdas in
+:func:`inspect.getsource`. Patch by Pablo Galindo