Fix some list behavior and add list.__ne__

src/runtime/list.cpp

@@ -508,6 +508,13 @@ Box* _listCmp(BoxedList* lhs, BoxedList* rhs, AST_TYPE::AST_TYPE op_type) {
     bool is_order
         = (op_type == AST_TYPE::Lt || op_type == AST_TYPE::LtE || op_type == AST_TYPE::Gt || op_type == AST_TYPE::GtE);
 
+    if (lsz != rsz) {
+        if (op_type == AST_TYPE::Eq)
+            return False;
+        if (op_type == AST_TYPE::NotEq)
+            return True;
+    }
+
     int n = std::min(lsz, rsz);
     for (int i = 0; i < n; i++) {
         Box* is_eq = compareInternal(lhs->elts->elts[i], rhs->elts->elts[i], AST_TYPE::Eq, NULL);
@@ -552,6 +559,16 @@ Box* listEq(BoxedList* self, Box* rhs) {
     return _listCmp(self, static_cast<BoxedList*>(rhs), AST_TYPE::Eq);
 }
 
+Box* listNe(BoxedList* self, Box* rhs) {
+    if (rhs->cls != list_cls) {
+        return NotImplemented;
+    }
+
+    LOCK_REGION(self->lock.asRead());
+
+    return _listCmp(self, static_cast<BoxedList*>(rhs), AST_TYPE::NotEq);
+}
+
 void setupList() {
     list_iterator_cls = new BoxedHeapClass(type_cls, object_cls, &listIteratorGCHandler, 0, sizeof(BoxedList), false);
 
@@ -569,6 +586,7 @@ void setupList() {
                        new BoxedFunction(boxRTFunction((void*)listIter, typeFromClass(list_iterator_cls), 1)));
 
     list_cls->giveAttr("__eq__", new BoxedFunction(boxRTFunction((void*)listEq, UNKNOWN, 2)));
+    list_cls->giveAttr("__ne__", new BoxedFunction(boxRTFunction((void*)listNe, UNKNOWN, 2)));
 
     list_cls->giveAttr("__repr__", new BoxedFunction(boxRTFunction((void*)listRepr, STR, 1)));
     list_cls->giveAttr("__str__", list_cls->getattr("__repr__"));

src/runtime/stacktrace.cpp

@@ -134,6 +134,9 @@ static void _printTraceback(const std::vector<const LineInfo*>& tb) {
     for (auto line : tb) {
         fprintf(stderr, "  File \"%s\", line %d, in %s:\n", line->file.c_str(), line->line, line->func.c_str());
 
+        if (line->line < 0)
+            continue;
+
         FILE* f = fopen(line->file.c_str(), "r");
         if (f) {
             assert(line->line < 10000000 && "Refusing to try to seek that many lines forward");

test/tests/comparisons.py

@@ -88,3 +88,11 @@ class Reverse(object):
         return self.n <= rhs.n
 
 print Reverse(4) > Reverse(3), Reverse(4) > Reverse(4)
+
+class EqOnly(object):
+    def __eq__(self, rhs):
+        print "eq"
+        return False
+
+print EqOnly() == 1
+print EqOnly() != 1

test/tests/list.py

@@ -76,3 +76,14 @@ print l
 x = [0, 1, 2]
 print 2 * x
 print x * 2
+
+print range(5) == range(5)
+print range(5) == range(4)
+
+class C(object):
+    def __eq__(self, rhs):
+        print "C.eq"
+        return False
+
+# Should not call C().__eq__
+print [C()] == [1, 2]