fixed "abc".count("", 100) == -96 error (hopefully, nobody's relying on

the current behaviour ;-)

diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index 489af20a16d53ffdb2511a99faed98e41e386d3c..5fe9fb92cfabe7602fdb9782722f19095bc0284d 100644 (file)
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -106,10 +106,18 @@ class CommonTest(unittest.TestCase):
         self.checkequal(3, 'aaa', 'count', 'a')
         self.checkequal(0, 'aaa', 'count', 'b')
         self.checkequal(0, 'aaa', 'count', 'b')
+        self.checkequal(2, 'aaa', 'count', 'a', 1)
+        self.checkequal(0, 'aaa', 'count', 'a', 10)
         self.checkequal(1, 'aaa', 'count', 'a', -1)
         self.checkequal(3, 'aaa', 'count', 'a', -10)
+        self.checkequal(1, 'aaa', 'count', 'a', 0, 1)
+        self.checkequal(3, 'aaa', 'count', 'a', 0, 10)
         self.checkequal(2, 'aaa', 'count', 'a', 0, -1)
         self.checkequal(0, 'aaa', 'count', 'a', 0, -10)
+        self.checkequal(3, 'aaa', 'count', '', 1)
+        self.checkequal(1, 'aaa', 'count', '', 10)
+        self.checkequal(2, 'aaa', 'count', '', -1)
+        self.checkequal(4, 'aaa', 'count', '', -10)
 
         self.checkraises(TypeError, 'hello', 'count')
         self.checkraises(TypeError, 'hello', 'count', 42)

diff --git a/Objects/stringlib/count.h b/Objects/stringlib/count.h
index 0bd02b59746f7393ff450f67ec04bb064176f32e..84a852f52e49fd8743607953ab7b2c6103094839 100644 (file)
--- a/Objects/stringlib/count.h
+++ b/Objects/stringlib/count.h
@@ -13,8 +13,11 @@ stringlib_count(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
 {
     Py_ssize_t count;
 
-    if (sub_len == 0)
+    if (sub_len == 0) {
+        if (str_len < 0)
+            return 1; /* start >= len(str) */
         return str_len + 1;
+    }
 
     count = fastsearch(str, str_len, sub, sub_len, FAST_COUNT);