Patch #1093585: raise a ValueError for negative history items in

remove_history and replace_history. Will backport to 2.4.

Misc/NEWS

@@ -34,6 +34,9 @@ Core and builtins
 Extension Modules
 -----------------
 
+- Patch #1093585: raise a ValueError for negative history items in readline.
+  {remove_history,replace_history}
+
 - The spwd module has been added, allowing access to the shadow password
   database.
 

Modules/readline.c

@@ -303,6 +303,11 @@ py_remove_history(PyObject *self, PyObject *args)
 
         if (!PyArg_ParseTuple(args, "i:remove_history", &entry_number))
                 return NULL;
+        if (entry_number < 0) {
+                PyErr_SetString(PyExc_ValueError,
+                                "History index cannot be negative");
+                return NULL;
+        }
         entry = remove_history(entry_number);
         if (!entry) {
                 PyErr_Format(PyExc_ValueError,
@@ -335,6 +340,11 @@ py_replace_history(PyObject *self, PyObject *args)
         if (!PyArg_ParseTuple(args, "is:replace_history", &entry_number, &line)) {
                 return NULL;
         }
+        if (entry_number < 0) {
+                PyErr_SetString(PyExc_ValueError,
+                                "History index cannot be negative");
+                return NULL;
+        }
         old_entry = replace_history_entry(entry_number, line, (void *)NULL);
         if (!old_entry) {
                 PyErr_Format(PyExc_ValueError,