From d33f966b05e8409bebe297ea141afefcd617fae8 Mon Sep 17 00:00:00 2001
From: albertexye <albertexye@gmail.com>
Date: Mon, 1 Apr 2024 14:36:18 -0400
Subject: [PATCH] when a negative start index is passed to str.find, 0 is used
 instead

---
 src/str.cpp     | 2 +-
 tests/04_str.py | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/str.cpp b/src/str.cpp
index b6ca04d2..9965e6eb 100644
--- a/src/str.cpp
+++ b/src/str.cpp
@@ -266,7 +266,7 @@ int utf8len(unsigned char c, bool suppress){
     }
 
     int Str::index(const Str& sub, int start) const {
-        if (start < 0 || start >= this->u8_length()) return -1;
+        if (start < 0) start = 0;
         auto p = std::search(data + start, data + size, sub.data, sub.data + sub.size);
         if(p == data + size) return -1;
         return p - data;
diff --git a/tests/04_str.py b/tests/04_str.py
index 4c3d5ef8..4801d117 100644
--- a/tests/04_str.py
+++ b/tests/04_str.py
@@ -242,4 +242,5 @@ except ValueError:
 
 assert a.find('1') == 0
 assert a.find('1', 1) == -1
+assert a.find('1', -1000000) == 0