fix: correct suffix boundary lookup for prefixed last names (#100)

nameparser/parser.py

@@ -980,7 +980,12 @@ def join_on_conjunctions(self, pieces: list[str], additional_parts_count: int =
                     try:
                         # if there are no more prefixes, look for a suffix to stop at
                         stop_at = next(iter(filter(self.is_suffix, pieces[i + 1:])))
-                        j = pieces.index(stop_at)
+                        # search from i + 1: filter() finds the value of stop_at
+                        # in pieces[i+1:] but pieces.index() without a start
+                        # argument searches from 0, so an earlier occurrence of
+                        # the same token (e.g. a suffix token that also appears
+                        # before the prefix) would be matched instead.
+                        j = pieces.index(stop_at, i + 1)
                         new_piece = ' '.join(pieces[i:j])
                         pieces = pieces[:i] + [new_piece] + pieces[j:]
                     except StopIteration:

pyproject.toml

@@ -43,7 +43,8 @@ dev = [
   "dill (>=0.2.5)",
   "sphinx (>=8)",
   "mypy (>=2.1)",
-  "ruff (>=0.15)"
+  "ruff (>=0.15)",
+  "pytest-timeout>=2.4.0",
 ]
 
 [tool.mypy]

tests/test_prefixes.py

@@ -1,3 +1,5 @@
+import pytest
+
 from nameparser import HumanName
 
 from tests.base import HumanNameTestBase
@@ -43,6 +45,50 @@ def test_prefix_before_two_part_last_name_with_acronym_suffix(self) -> None:
         self.m(hn.last, "von bergen wessels", hn)
         self.m(hn.suffix, "M.D.", hn)
 
+    def test_title_before_and_after_prefixed_last_name(self) -> None:
+        # Issue #100: a repeated title/suffix token ("dr") before AND after a
+        # prefixed last name used to corrupt the middle name into
+        # " dr Vincent van" because the suffix-boundary lookup matched the
+        # LEADING "dr" instead of the trailing one.
+        hn = HumanName("dr Vincent van Gogh dr")
+        self.m(hn.title, "dr", hn)
+        self.m(hn.first, "Vincent", hn)
+        self.m(hn.middle, "", hn)
+        self.m(hn.last, "van Gogh", hn)
+        self.m(hn.suffix, "dr", hn)
+
+    def test_suffix_token_collision_with_two_word_prefix(self) -> None:
+        # Same fix as #100 but with a two-word prefix ("van der"). Exercises a
+        # different iteration count through the prefix-joining loop.
+        hn = HumanName("dr Vincent van der Gogh dr")
+        self.m(hn.title, "dr", hn)
+        self.m(hn.first, "Vincent", hn)
+        self.m(hn.middle, "", hn)
+        self.m(hn.last, "van der Gogh", hn)
+        self.m(hn.suffix, "dr", hn)
+
+    def test_title_before_and_after_prefixed_last_name_with_middle(self) -> None:
+        # The pre-fix bug corrupted the middle field; verify it is not disturbed
+        # when a genuine middle name is present alongside the repeated token.
+        hn = HumanName("dr Vincent James van Gogh dr")
+        self.m(hn.title, "dr", hn)
+        self.m(hn.first, "Vincent", hn)
+        self.m(hn.middle, "James", hn)
+        self.m(hn.last, "van Gogh", hn)
+        self.m(hn.suffix, "dr", hn)
+
+    @pytest.mark.timeout(2)
+    def test_many_repeated_prefixes_does_not_blow_up(self) -> None:
+        # Issue #108: a name with a long run of repeated prefixes used to grow
+        # the pieces list exponentially and exhaust memory. The 2-second timeout
+        # enforces this locally and in CI — if the test hangs, an exponential
+        # regression has been reintroduced.
+        name = "Jan " + "van der " * 30 + "Berg"
+        hn = HumanName(name)
+        self.assertFalse(hn.unparsable)
+        self.m(hn.first, "Jan", hn)
+        self.assertIn("Berg", hn.last)
+
     def test_two_part_last_name_with_suffix_comma(self) -> None:
         hn = HumanName("pennie von bergen wessels, III")
         self.m(hn.first, "pennie", hn)