[3.13] gh-58956: Set f_trace on frames with breakpoints after setting a new breakpoin...

gh-58956: Set f_trace on frames with breakpoints after setting a new breakpoint (GH-124454)
(cherry picked from commit 12eaadc0ad33411bb02945d700b6ed7e758bb188)

Co-authored-by: Tian Gao <gaogaotiantian@hotmail.com>

diff --git a/Lib/bdb.py b/Lib/bdb.py
index a0e46e7f413816a383d3271ed2ba591ad6c29951..ece0a29fe9f3b103a762b0ee2c98ca7a8f6f23ed 100644 (file)
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@@ -439,6 +439,14 @@ class Bdb:
             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 5fe03cc33f34be9e0464bc3ce03808c37065b565..d8b9da61d0a308e3c9ac7cec4044ca3896e8cc85 100644 (file)
--- a/Lib/test/test_pdb.py
+++ b/Lib/test/test_pdb.py
@@ -3184,6 +3184,36 @@ def bœr():
         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_step_into_botframe(self):
         # gh-125422
         # pdb should not be able to step into the botframe (bdb.py)

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 (file)
index 0000000..a882a63
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-09-24-18-16-59.gh-issue-58956.0wFrBR.rst
@@ -0,0 +1 @@
+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.