Fix (unreleased) regression with missing start attributes

This is not exactly the same as before (which was only done via the module's `set_trace`), and therefore still gets updated in `Pdb.set_trace()` (after initially in `__init__`).
pdbpp · May 25, 2019 · 8a3018c · 8a3018c
1 parent f2179d8
commit 8a3018c
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Showing 3 changed files with 59 additions and 27 deletions.
diff --git a/pdb.py b/pdb.py
@@ -22,8 +22,10 @@
 import re
 import signal
 from collections import OrderedDict
-from fancycompleter import Completer, ConfigurableClass, Color
+
 import fancycompleter
+import six
+from fancycompleter import Color, Completer, ConfigurableClass
 
 __author__ = 'Antonio Cuni <anto.cuni@gmail.com>'
 __url__ = 'http://github.com/antocuni/pdb'
@@ -170,6 +172,37 @@ def __repr__(self):
 undefined = Undefined()
 
 
+class PdbMeta(type):
+    def __call__(cls, *args, **kwargs):
+        """Reuse an existing instance with ``pdb.set_trace()``."""
+        use_global_pdb = kwargs.get("use_global_pdb", True)
+        global_pdb = getattr(local, "GLOBAL_PDB", None)
+
+        calling_frame = sys._getframe().f_back
+        called_for_set_trace = (
+            calling_frame.f_code.co_name == "set_trace"
+            and calling_frame.f_back
+            and "set_trace" in calling_frame.f_back.f_code.co_names)
+
+        if use_global_pdb and global_pdb and called_for_set_trace:
+            if hasattr(global_pdb, "botframe"):
+                # Do not stop while tracing is active (in _set_stopinfo).
+                # But skip it with instances that have not called set_trace
+                # before.
+                global_pdb.set_continue()
+            global_pdb._skip_init = True
+            return global_pdb
+
+        obj = cls.__new__(cls)
+        if called_for_set_trace:
+            kwargs.setdefault("start_filename", calling_frame.f_code.co_filename)
+            kwargs.setdefault("start_lineno", calling_frame.f_lineno)
+        obj.__init__(*args, **kwargs)
+        local.GLOBAL_PDB = obj
+        return obj
+
+
+@six.add_metaclass(PdbMeta)
 class Pdb(pdb.Pdb, ConfigurableClass, object):
 
     DefaultConfig = DefaultConfig
@@ -205,32 +238,6 @@ def __init__(self, *args, **kwds):
         self.hidden_frames = []
         self.stdout = self.ensure_file_can_write_unicode(self.stdout)
 
-    def __new__(cls, *args, **kwargs):
-        """Reuse an existing instance with ``pdb.set_trace()``."""
-        use_global_pdb = kwargs.get("use_global_pdb", True)
-        global_pdb = getattr(local, "GLOBAL_PDB", None)
-        if use_global_pdb and global_pdb:
-            called_for_set_trace = False
-            frame = sys._getframe()
-            while frame.f_back:
-                frame = frame.f_back
-                if (frame.f_code.co_name == "set_trace"
-                        and frame.f_back
-                        and "set_trace" in frame.f_back.f_code.co_names):
-                    called_for_set_trace = True
-                    break
-            if called_for_set_trace:
-                if hasattr(global_pdb, "botframe"):
-                    # Do not stop while tracing is active (in _set_stopinfo).
-                    # But skip it with instances that have not called set_trace
-                    # before.
-                    global_pdb.set_continue()
-                global_pdb._skip_init = True
-                return global_pdb
-        ret = super(Pdb, cls).__new__(cls)
-        local.GLOBAL_PDB = ret
-        return ret
-
     def ensure_file_can_write_unicode(self, f):
         # Wrap with an encoder, but only if not already wrapped
         if (not hasattr(f, 'stream')

diff --git a/setup.py b/setup.py
@@ -84,6 +84,7 @@ def run(self):
         "fancycompleter>=0.8",
         "wmctrl",
         "pygments",
+        "six",
     ],
     extras_require={
         'funcsigs': ["funcsigs"],

diff --git a/testing/test_pdb.py b/testing/test_pdb.py
@@ -3595,3 +3595,27 @@ def fn():
    5 frames hidden .*
 # c
 """)
+
+
+def test_config_gets_start_filename():
+    def fn():
+        setup_lineno = set_trace.__code__.co_firstlineno + 8
+        set_trace_lineno = sys._getframe().f_lineno + 8
+
+        class MyConfig(ConfigTest):
+            def setup(self, pdb):
+                print("config_setup")
+                assert pdb.start_filename == __file__
+                assert pdb.start_lineno == setup_lineno
+
+        set_trace(Config=MyConfig)
+
+        assert pdb.local.GLOBAL_PDB.start_lineno == set_trace_lineno
+
+    check(fn, r"""
+config_setup
+[NUM] > .*fn()
+-> assert pdb.local.GLOBAL_PDB.start_lineno == set_trace_lineno
+   5 frames hidden .*
+# c
+""")