diff --git a/Lib/_pyrepl/commands.py b/Lib/_pyrepl/commands.py
index 10127e58897a58..e603dd00d8ba49 100644
--- a/Lib/_pyrepl/commands.py
+++ b/Lib/_pyrepl/commands.py
@@ -169,7 +169,7 @@ class unix_word_rubout(KillCommand):
     def do(self) -> None:
         r = self.reader
         for i in range(r.get_arg()):
-            self.kill_range(r.bow(), r.pos)
+            self.kill_range(r.bow_whitespace(), r.pos)
 
 
 class kill_word(KillCommand):
diff --git a/Lib/_pyrepl/reader.py b/Lib/_pyrepl/reader.py
index 9ab92f64d1ef63..27838834980478 100644
--- a/Lib/_pyrepl/reader.py
+++ b/Lib/_pyrepl/reader.py
@@ -417,6 +417,22 @@ def bow(self, p: int | None = None) -> int:
             p -= 1
         return p + 1
 
+    def bow_whitespace(self, p: int | None = None) -> int:
+        """Return the 0-based index of the whitespace-delimited word break
+        preceding p most immediately.
+
+        p defaults to self.pos; only whitespace is considered a word
+        boundary, matching the behavior of unix-word-rubout in bash/readline."""
+        if p is None:
+            p = self.pos
+        b = self.buffer
+        p -= 1
+        while p >= 0 and b[p] in (" ", "\n"):
+            p -= 1
+        while p >= 0 and b[p] not in (" ", "\n"):
+            p -= 1
+        return p + 1
+
     def eow(self, p: int | None = None) -> int:
         """Return the 0-based index of the word break following p most
         immediately.
diff --git a/Lib/test/test_pyrepl/test_reader.py b/Lib/test/test_pyrepl/test_reader.py
index b1b6ae16a1e592..c9d6184135378d 100644
--- a/Lib/test/test_pyrepl/test_reader.py
+++ b/Lib/test/test_pyrepl/test_reader.py
@@ -558,3 +558,47 @@ def test_control_characters(self):
         reader, _ = handle_all_events(events)
         self.assert_screen_equal(reader, 'flag = "🏳️\\u200d🌈"', clean=True)
         self.assert_screen_equal(reader, 'flag {o}={z} {s}"🏳️\\u200d🌈"{z}'.format(**colors))
+
+
+class TestBowWhitespace(TestCase):
+    def test_bow_whitespace_stops_at_whitespace(self):
+        # GH#146044
+        # unix-word-rubout (ctrl-w) should use whitespace boundaries,
+        # not punctuation boundaries like bow() does
+        reader = prepare_reader(prepare_console())
+        reader.buffer = list("foo.bar baz")
+        reader.pos = len(reader.buffer)  # cursor at end
+
+        # bow_whitespace from end should jump to start of "baz"
+        result = reader.bow_whitespace()
+        self.assertEqual(result, 8)  # index of 'b' in "baz"
+
+    def test_bow_whitespace_includes_punctuation_in_word(self):
+        # GH#146044
+        reader = prepare_reader(prepare_console())
+        reader.buffer = list("foo.bar(baz) qux")
+        reader.pos = 12  # cursor after ")"
+
+        # bow_whitespace should treat "foo.bar(baz)" as one word
+        result = reader.bow_whitespace()
+        self.assertEqual(result, 0)
+
+    def test_bow_stops_at_punctuation(self):
+        # Verify existing bow() still uses syntax_table (punctuation boundary)
+        reader = prepare_reader(prepare_console())
+        reader.buffer = list("foo.bar baz")
+        reader.pos = len(reader.buffer)
+
+        result = reader.bow()
+        self.assertEqual(result, 8)  # same — "baz" is all word chars
+
+    def test_bow_vs_bow_whitespace_difference(self):
+        # The key difference: bow() stops at '.', bow_whitespace() does not
+        reader = prepare_reader(prepare_console())
+        reader.buffer = list("foo.bar")
+        reader.pos = len(reader.buffer)
+
+        # bow() stops at '.' → returns index of 'b' in "bar"
+        self.assertEqual(reader.bow(), 4)
+        # bow_whitespace() treats entire "foo.bar" as one word
+        self.assertEqual(reader.bow_whitespace(), 0)
diff --git a/Lib/test/test_trace.py b/Lib/test/test_trace.py
index 19eee19bdea6d5..0f882cae7dc6aa 100644
--- a/Lib/test/test_trace.py
+++ b/Lib/test/test_trace.py
@@ -590,5 +590,33 @@ def test_no_source_file(self):
         self.assertIn(f"{filename}({firstlineno + 4})", out[4])
 
 
+class TestCoverageResultsInit(unittest.TestCase):
+    def test_counts_dict_is_copied(self):
+        # gh-145865: CoverageResults.__init__ should copy the counts dict
+        # to avoid mutating the caller's dict on update()
+        from trace import CoverageResults
+
+        counts = {}
+        cr = CoverageResults(counts=counts)
+        cr.update(CoverageResults(counts={("file.py", 1): 5}))
+        self.assertEqual(counts, {})  # original must not be mutated
+
+    def test_calledfuncs_dict_is_copied(self):
+        from trace import CoverageResults
+
+        calledfuncs = {}
+        cr = CoverageResults(calledfuncs=calledfuncs)
+        cr.update(CoverageResults(calledfuncs={("file.py", "mod", "func"): 1}))
+        self.assertEqual(calledfuncs, {})
+
+    def test_callers_dict_is_copied(self):
+        from trace import CoverageResults
+
+        callers = {}
+        cr = CoverageResults(callers=callers)
+        cr.update(CoverageResults(callers={(("a.py", "m", "f"), ("b.py", "m", "g")): 1}))
+        self.assertEqual(callers, {})
+
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/Lib/trace.py b/Lib/trace.py
index cd3a6d30661da3..15894921d3e434 100644
--- a/Lib/trace.py
+++ b/Lib/trace.py
@@ -155,7 +155,7 @@ def __init__(self, counts=None, calledfuncs=None, infile=None,
         self.counts = counts
         if self.counts is None:
             self.counts = {}
-        self.counter = self.counts.copy() # map (filename, lineno) to count
+        self.counts = self.counts.copy()  # map (filename, lineno) to count
         self.calledfuncs = calledfuncs
         if self.calledfuncs is None:
             self.calledfuncs = {}