[Python-checkins] GH-95818: Skip incomplete frames in `PyThreadState_GetFrame` (GH-95886) (#95890)

[pablogsal]

https://github.com/python/cpython/commit/6fc90c11835f1af869a47724ab9742535b73fe7b
commit: 6fc90c11835f1af869a47724ab9742535b73fe7b
branch: 3.11
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: pablogsal <Pablogsal at gmail.com>
date: 2022-08-12T19:40:49+01:00
summary:

GH-95818: Skip incomplete frames in `PyThreadState_GetFrame` (GH-95886) (#95890)

(cherry picked from commit 1b46d118e6e72daa64b98cafddb406c68b419efa)

Co-authored-by: Mark Shannon <mark at hotpy.org>

Co-authored-by: Mark Shannon <mark at hotpy.org>

files:
A Misc/NEWS.d/next/Core and Builtins/2022-08-11-11-01-56.gh-issue-95818.iClLdl.rst
M Lib/test/test_frame.py
M Python/pystate.c

diff --git a/Lib/test/test_frame.py b/Lib/test/test_frame.py
index a715e725a7e4..9fab17684eec 100644
--- a/Lib/test/test_frame.py
+++ b/Lib/test/test_frame.py
@@ -235,6 +235,28 @@ def inner():
                          r"^<frame at 0x[0-9a-fA-F]+, file %s, line %d, code inner>$"
                          % (file_repr, offset + 5))
 
+class TestIncompleteFrameAreInvisible(unittest.TestCase):
+
+    def test_issue95818(self):
+        #See GH-95818 for details
+        import gc
+        self.addCleanup(gc.set_threshold, *gc.get_threshold())
+
+        gc.set_threshold(1,1,1)
+        class GCHello:
+            def __del__(self):
+                print("Destroyed from gc")
+
+        def gen():
+            yield
+
+        fd = open(__file__)
+        l = [fd, GCHello()]
+        l.append(l)
+        del fd
+        del l
+        gen()
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-08-11-11-01-56.gh-issue-95818.iClLdl.rst b/Misc/NEWS.d/next/Core and Builtins/2022-08-11-11-01-56.gh-issue-95818.iClLdl.rst
new file mode 100644
index 000000000000..1e243f5614f1
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-08-11-11-01-56.gh-issue-95818.iClLdl.rst	
@@ -0,0 +1 @@
+Skip over incomplete frames in :c:func:`PyThreadState_GetFrame`.
diff --git a/Python/pystate.c b/Python/pystate.c
index df56c0530f05..2e4585688ea8 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -1255,10 +1255,14 @@ PyFrameObject*
 PyThreadState_GetFrame(PyThreadState *tstate)
 {
     assert(tstate != NULL);
-    if (tstate->cframe->current_frame == NULL) {
+    _PyInterpreterFrame *f = tstate->cframe->current_frame;
+    while (f && _PyFrame_IsIncomplete(f)) {
+        f = f->previous;
+    }
+    if (f == NULL) {
         return NULL;
     }
-    PyFrameObject *frame = _PyFrame_GetFrameObject(tstate->cframe->current_frame);
+    PyFrameObject *frame = _PyFrame_GetFrameObject(f);
     if (frame == NULL) {
         PyErr_Clear();
     }