[PATCH 1 of 5] index: check more aggressively when adding new entries

[Bryan O'Sullivan]

# HG changeset patch
# User Bryan O'Sullivan <bryano at fb.com>
# Date 1336000671 25200
# Branch stable
# Node ID 7376bc611dbdb05b2cee683eeed1736517ef5938
# Parent  55fecd29c30c2db64093d6aff7bbefec1a4f0d58
index: check more aggressively when adding new entries

This makes it impossible to construct a revlog entry with bogus
parents.

diff -r 55fecd29c30c -r 7376bc611dbd mercurial/parsers.c
--- a/mercurial/parsers.c	Wed May 02 16:17:50 2012 -0700
+++ b/mercurial/parsers.c	Wed May 02 16:17:51 2012 -0700
@@ -416,10 +416,11 @@
 
 static PyObject *index_insert(indexObject *self, PyObject *args)
 {
-	PyObject *obj;
+	PyObject *obj, *o1, *o2;
 	char *node;
 	long offset;
 	Py_ssize_t len, nodelen;
+	long p1, p2;
 
 	if (!PyArg_ParseTuple(args, "lO", &offset, &obj))
 		return NULL;
@@ -449,6 +450,21 @@
 		return NULL;
 	}
 
+	o1 = PyTuple_GET_ITEM(obj, 5);
+	o2 = PyTuple_GET_ITEM(obj, 6);
+	if (!PyInt_Check(o1) || !PyInt_Check(o2)) {
+		PyErr_SetString(PyExc_TypeError, "parent revs are not ints");
+		return NULL;
+	}
+	p1 = PyInt_AS_LONG(o1);
+	p2 = PyInt_AS_LONG(o2);
+	if (p1 < -1 || p1 >= offset || p2 < -1 || p2 >= offset ||
+	    (p1 == -1 ? p1 != p2 : p1 == p2)) {
+		PyErr_Format(PyExc_ValueError,
+			     "parent revs are invalid (%ld, %ld)", p1, p2);
+		return NULL;
+	}
+
 	if (self->added == NULL) {
 		self->added = PyList_New(0);
 		if (self->added == NULL)