fix(utils): handle empty string in match_regex_list

Author: Ishaan Samantray

sentry_sdk/utils.py

@@ -1740,7 +1740,7 @@ def match_regex_list(
         return False
 
     for item_matcher in regex_list:
-        if not substring_matching and item_matcher[-1] != "$":
+        if not substring_matching and (not item_matcher or item_matcher[-1] != "$"):
             item_matcher += "$"
 
         matched = re.search(item_matcher, item)

tests/test_utils.py

@@ -562,6 +562,14 @@ def test_match_regex_list(item, regex_list, expected_result):
     assert match_regex_list(item, regex_list) == expected_result
 
 
+def test_match_regex_list_empty_string_pattern():
+    # An empty-string pattern must not raise IndexError (regression test).
+    result = match_regex_list("anything", [""])
+    assert isinstance(result, bool)
+    assert match_regex_list("foobar", ["foo"]) is False
+    assert match_regex_list("foo", ["foo"]) is True
+
+
 @pytest.mark.parametrize(
     "version,expected_result",
     [