fix: breakpoint in pdb can cause crash

Signed-off-by: yihong0618 <zouzou0208@gmail.com>

Author: yihong0618

Lib/pdb.py

@@ -926,6 +926,9 @@ def _read_code(self, line):
 
     def default(self, line):
         if line[:1] == '!': line = line[1:].strip()
+        if not self.curframe:
+            self.error("No current frame.")
+            return
         locals = self.curframe.f_locals
         globals = self.curframe.f_globals
         try:
@@ -2131,6 +2134,9 @@ def do_list(self, arg):
             first = self.lineno + 1
         if last is None:
             last = first + 10
+        if not self.curframe:
+            self.error('No current frame.')
+            return
         filename = self.curframe.f_code.co_filename
         breaklist = self.get_file_breaks(filename)
         try:
@@ -2153,6 +2159,9 @@ def do_longlist(self, arg):
         if arg:
             self._print_invalid_arg(arg)
             return
+        if not self.curframe:
+            self.error('No current frame.')
+            return
         filename = self.curframe.f_code.co_filename
         breaklist = self.get_file_breaks(filename)
         try:

Misc/NEWS.d/next/Library/2025-09-08-17-50-33.gh-issue-138641.nBPvKe.rst

@@ -0,0 +1 @@
+Fix: breakpoint() in pdb can cause crash.