PR: Fix recursive debugger

spyder_kernels/customize/spydercustomize.py

@@ -27,7 +27,7 @@
 
 from spyder_kernels.comms.frontendcomm import CommError, frontend_request
 from spyder_kernels.customize.namespace_manager import NamespaceManager
-from spyder_kernels.customize.spyderpdb import SpyderPdb
+from spyder_kernels.customize.spyderpdb import SpyderPdb, enter_debugger
 from spyder_kernels.customize.umr import UserModuleReloader
 from spyder_kernels.py3compat import TimeoutError, PY2, _print, encode
 
@@ -374,18 +374,6 @@ def get_current_file_name():
         return None
 
 
-def get_debugger(filename):
-    """Get a debugger for a given filename."""
-    debugger = pdb.Pdb()
-    filename = debugger.canonic(filename)
-    debugger._wait_for_mainpyfile = 1
-    debugger.mainpyfile = filename
-    debugger._user_requested_quit = 0
-    if os.name == 'nt':
-        filename = filename.replace('\\', '/')
-    return debugger, filename
-
-
 def count_leading_empty_lines(cell):
     """Count the number of leading empty cells."""
     if PY2:
@@ -597,10 +585,12 @@ def debugfile(filename=None, args=None, wdir=None, post_mortem=False,
         filename = get_current_file_name()
         if filename is None:
             return
-    debugger, filename = get_debugger(filename)
-    debugger.continue_if_has_breakpoints = True
-    debugger.run("runfile(%r, args=%r, wdir=%r, current_namespace=%r)" % (
-        filename, args, wdir, current_namespace))
+
+    enter_debugger(
+        filename, True,
+        "runfile({}" +
+        ", args=%r, wdir=%r, current_namespace=%r)" % (
+            args, wdir, current_namespace))
 
 
 builtins.debugfile = debugfile
@@ -678,11 +668,10 @@ def debugcell(cellname, filename=None, post_mortem=False):
         if filename is None:
             return
 
-    debugger, filename = get_debugger(filename)
-    # The breakpoint might not be in the cell
-    debugger.continue_if_has_breakpoints = False
-    debugger.run("runcell({}, {})".format(
-        repr(cellname), repr(filename)))
+    enter_debugger(
+        filename, False,
+        "runcell({}, ".format(repr(cellname)) +
+        "{})")
 
 
 builtins.debugcell = debugcell

spyder_kernels/customize/spyderpdb.py

@@ -7,8 +7,9 @@
 """Spyder debugger."""
 
 import bdb
-import sys
 import logging
+import os
+import sys
 import traceback
 from collections import namedtuple
 
@@ -512,7 +513,7 @@ def user_return(self, frame, return_value):
             if (self.mainpyfile != self.canonic(frame.f_code.co_filename)
                     or frame.f_lineno <= 0):
                 return
-            self._wait_for_mainpyfile = 0
+            self._wait_for_mainpyfile = False
         super(SpyderPdb, self).user_return(frame, return_value)
 
     def _cmdloop(self):
@@ -700,3 +701,44 @@ def runcall(self, *args, **kwds):
         """
         with DebugWrapper(self):
             super(SpyderPdb, self).runcall(*args, **kwds)
+
+
+def enter_debugger(filename, continue_if_has_breakpoints, code_format):
+    """Enter debugger. Code format should be a format that accept filename."""
+    kernel = get_ipython().kernel
+    recursive = kernel.is_debugging()
+    if recursive:
+        parent_debugger = kernel._pdb_obj
+        sys.settrace(None)
+        globals = parent_debugger.curframe.f_globals
+        locals = parent_debugger.curframe_locals
+        # Create child debugger
+        debugger = SpyderPdb(
+            completekey=parent_debugger.completekey,
+            stdin=parent_debugger.stdin, stdout=parent_debugger.stdout)
+        debugger.use_rawinput = parent_debugger.use_rawinput
+        debugger.prompt = "(%s) " % parent_debugger.prompt.strip()
+    else:
+        debugger = SpyderPdb()
+
+    filename = debugger.canonic(filename)
+    debugger._wait_for_mainpyfile = True
+    debugger.mainpyfile = filename
+    debugger.continue_if_has_breakpoints = continue_if_has_breakpoints
+    debugger._user_requested_quit = False
+
+    if os.name == 'nt':
+        filename = filename.replace('\\', '/')
+
+    code = code_format.format(repr(filename))
+
+    if recursive:
+        # Enter recursive debugger
+        sys.call_tracing(debugger.run, (code, globals, locals))
+        # Reset parent debugger
+        sys.settrace(parent_debugger.trace_dispatch)
+        parent_debugger.lastcmd = debugger.lastcmd
+        kernel._register_pdb_session(parent_debugger)
+    else:
+        # The breakpoint might not be in the cell
+        debugger.run(code)