From 4ccb22706d60ef69f3e3a8ba409f12ef5e534533 Mon Sep 17 00:00:00 2001
From: Tian Gao <gaogaotiantian@hotmail.com>
Date: Fri, 15 Mar 2024 02:36:04 -0700
Subject: [PATCH] gh-90095: Ignore empty lines and comments in `.pdbrc`
 (#116834)

---
 Doc/library/pdb.rst                           |  3 ++-
 Lib/pdb.py                                    |  5 ++++-
 Lib/test/test_pdb.py                          | 19 +++++++++++++++++++
 ...4-03-14-20-59-28.gh-issue-90095.7UaJ1U.rst |  1 +
 4 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2024-03-14-20-59-28.gh-issue-90095.7UaJ1U.rst

diff --git a/Doc/library/pdb.rst b/Doc/library/pdb.rst
index 1cfca0cf68a946b..ac3007f70c3534d 100644
--- a/Doc/library/pdb.rst
+++ b/Doc/library/pdb.rst
@@ -288,7 +288,8 @@ There are three preset *convenience variables*:
 
 If a file :file:`.pdbrc` exists in the user's home directory or in the current
 directory, it is read with ``'utf-8'`` encoding and executed as if it had been
-typed at the debugger prompt.  This is particularly useful for aliases.  If both
+typed at the debugger prompt, with the exception that empty lines and lines
+starting with ``#`` are ignored.  This is particularly useful for aliases.  If both
 files exist, the one in the home directory is read first and aliases defined there
 can be overridden by the local file.
 
diff --git a/Lib/pdb.py b/Lib/pdb.py
index f4d19386703de03..88ea900e63f42b6 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -364,7 +364,10 @@ def setup(self, f, tb):
             )
 
         if self.rcLines:
-            self.cmdqueue = self.rcLines
+            self.cmdqueue = [
+                line for line in self.rcLines
+                if line.strip() and not line.strip().startswith("#")
+            ]
             self.rcLines = []
 
     # Override Bdb methods
diff --git a/Lib/test/test_pdb.py b/Lib/test/test_pdb.py
index 44728542787423e..69691e930562bc7 100644
--- a/Lib/test/test_pdb.py
+++ b/Lib/test/test_pdb.py
@@ -2933,8 +2933,27 @@ def test_pdbrc_basic(self):
         """)
 
         stdout, stderr = self.run_pdb_script(script, 'q\n', pdbrc=pdbrc, remove_home=True)
+        self.assertNotIn("SyntaxError", stdout)
         self.assertIn("a+8=9", stdout)
 
+    def test_pdbrc_empty_line(self):
+        """Test that empty lines in .pdbrc are ignored."""
+
+        script = textwrap.dedent("""
+            a = 1
+            b = 2
+            c = 3
+        """)
+
+        pdbrc = textwrap.dedent("""
+            n
+
+        """)
+
+        stdout, stderr = self.run_pdb_script(script, 'q\n', pdbrc=pdbrc, remove_home=True)
+        self.assertIn("b = 2", stdout)
+        self.assertNotIn("c = 3", stdout)
+
     def test_pdbrc_alias(self):
         script = textwrap.dedent("""
             class A:
diff --git a/Misc/NEWS.d/next/Library/2024-03-14-20-59-28.gh-issue-90095.7UaJ1U.rst b/Misc/NEWS.d/next/Library/2024-03-14-20-59-28.gh-issue-90095.7UaJ1U.rst
new file mode 100644
index 000000000000000..b7024c74f7aa7de
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-03-14-20-59-28.gh-issue-90095.7UaJ1U.rst
@@ -0,0 +1 @@
+Ignore empty lines and comments in ``.pdbrc``