Index: Lib/test/string_tests.py
===================================================================
--- Lib/test/string_tests.py	(revision 76715)
+++ Lib/test/string_tests.py	(working copy)
@@ -185,6 +185,9 @@
         self.checkequal(-1, '', 'find', 'xx', 1, 1)
         self.checkequal(-1, '', 'find', 'xx', sys.maxint, 0)
 
+        # issue 7458
+        self.checkequal(-1, 'ab', 'find', 'xxx', sys.maxsize + 1, 0)
+
         # For a variety of combinations,
         #    verify that str.find() matches __contains__
         #    and that the found substring is really at that location
@@ -230,6 +233,9 @@
         self.checkraises(TypeError, 'hello', 'rfind')
         self.checkraises(TypeError, 'hello', 'rfind', 42)
 
+        # issue 7458
+        self.checkequal(-1, 'ab', 'rfind', 'xxx', sys.maxsize + 1, 0)
+
     def test_index(self):
         self.checkequal(0, 'abcdefghiabc', 'index', '')
         self.checkequal(3, 'abcdefghiabc', 'index', 'def')
Index: Objects/stringlib/find.h
===================================================================
--- Objects/stringlib/find.h	(revision 76715)
+++ Objects/stringlib/find.h	(working copy)
@@ -33,13 +33,13 @@
                 Py_ssize_t offset)
 {
     /* XXX - create reversefastsearch helper! */
+    if (str_len < 0)
+        return -1;
     if (sub_len == 0) {
-        if (str_len < 0)
-            return -1;
-	return str_len + offset;
+        return str_len + offset;
     } else {
-	Py_ssize_t j, pos = -1;
-	for (j = str_len - sub_len; j >= 0; --j)
+        Py_ssize_t j, pos = -1;
+        for (j = str_len - sub_len; j >= 0; --j)
             if (STRINGLIB_CMP(str+j, sub, sub_len) == 0) {
                 pos = j + offset;
                 break;