From a7e07e5aea7965e8eb04ad7e242f85ae1787b629 Mon Sep 17 00:00:00 2001
From: Tian Gao <gaogaotiantian@hotmail.com>
Date: Tue, 24 Sep 2024 11:07:14 -0700
Subject: [PATCH 1/4] Set f_trace on frames with breakpoints after setting a
 new breakpoint

---
 Lib/bdb.py           |  8 ++++++++
 Lib/test/test_pdb.py | 30 ++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/Lib/bdb.py b/Lib/bdb.py
index d7543017940d4f..42f9fd2a98eeff 100644
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@@ -439,6 +439,14 @@ def set_break(self, filename, lineno, temporary=False, cond=None,
             return 'Line %s:%d does not exist' % (filename, lineno)
         self._add_to_breaks(filename, lineno)
         bp = Breakpoint(filename, lineno, temporary, cond, funcname)
+        # After we set a new breakpoint, we need to search through all frames
+        # and set f_trace to trace_dispatch if there could be a breakpoint in
+        # that frame.
+        frame = self.enterframe
+        while frame:
+            if self.break_anywhere(frame):
+                frame.f_trace = self.trace_dispatch
+            frame = frame.f_back
         return None
 
     def _load_breaks(self):
diff --git a/Lib/test/test_pdb.py b/Lib/test/test_pdb.py
index db7d1b1e9cd935..99a1e18a9e09d5 100644
--- a/Lib/test/test_pdb.py
+++ b/Lib/test/test_pdb.py
@@ -3276,6 +3276,36 @@ def test_issue26053(self):
         self.assertRegex(res, "Restarting .* with arguments:\na b c")
         self.assertRegex(res, "Restarting .* with arguments:\nd e f")
 
+    def test_issue58956(self):
+        # Set a breakpoint in a function that already exists on the call stack
+        # should enable the trace function for the frame.
+        script = """
+            import bar
+            def foo():
+                ret = bar.bar()
+                pass
+            foo()
+        """
+        commands = """
+            b bar.bar
+            c
+            b main.py:5
+            c
+            p ret
+            quit
+        """
+        bar = """
+            def bar():
+                return 42
+        """
+        with open('bar.py', 'w') as f:
+            f.write(textwrap.dedent(bar))
+        self.addCleanup(os_helper.unlink, 'bar.py')
+        stdout, stderr = self.run_pdb_script(script, commands)
+        lines = stdout.splitlines()
+        self.assertIn('-> pass', lines)
+        self.assertIn('(Pdb) 42', lines)
+
     def test_pdbrc_basic(self):
         script = textwrap.dedent("""
             a = 1

From bd72ec978629d3221c30074e5b5f1e74ec20c32c Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Tue, 24 Sep 2024 18:17:04 +0000
Subject: [PATCH 2/4] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst   | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst

diff --git a/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
new file mode 100644
index 00000000000000..7d28f9eab09279
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
@@ -0,0 +1 @@
+Setting a :mod:`pdb` breakpoint on a function that's already in the call stack will enable the trace function on that frame so the breakpoint would trigger.

From 5a32d943d3348bd75799d6b5facecaacf7a534fa Mon Sep 17 00:00:00 2001
From: Tian Gao <gaogaotiantian@hotmail.com>
Date: Tue, 15 Oct 2024 10:58:33 -0400
Subject: [PATCH 3/4] Update 2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst

---
 .../next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
index 7d28f9eab09279..190122831d2051 100644
--- a/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
+++ b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
@@ -1 +1 @@
-Setting a :mod:`pdb` breakpoint on a function that's already in the call stack will enable the trace function on that frame so the breakpoint would trigger.
+Fixed a bug in :mod:`pdb` where sometimes the breakpoint won't trigger if it was set on a function in the call stack already.

From 0cb7fe7b7b787ff19cb23991cadcc5f05381a123 Mon Sep 17 00:00:00 2001
From: Tian Gao <gaogaotiantian@hotmail.com>
Date: Tue, 15 Oct 2024 11:04:30 -0400
Subject: [PATCH 4/4] Update
 Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
---
 .../next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
index 190122831d2051..a882a632fddf1b 100644
--- a/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
+++ b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
@@ -1 +1 @@
-Fixed a bug in :mod:`pdb` where sometimes the breakpoint won't trigger if it was set on a function in the call stack already.
+Fixed a bug in :mod:`pdb` where sometimes the breakpoint won't trigger if it was set on a function which is already in the call stack.