From 23f9fb0ae92b182e645ed52e729ff33575513cf4 Mon Sep 17 00:00:00 2001
From: Tim Wojtulewicz <tim@corelight.com>
Date: Thu, 13 Jun 2019 15:37:31 -0700
Subject: [PATCH] Allow assignment for vectors using slices

---
 src/Expr.cc                                | 22 +++++++++++++++++++++-
 testing/btest/Baseline/language.vector/out |  2 ++
 testing/btest/language/vector.zeek         |  4 ++++
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/Expr.cc b/src/Expr.cc
index 8d5bfcdc83..768d70ef0b 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -3199,7 +3199,26 @@ void IndexExpr::Assign(Frame* f, Val* v, Opcode op)
 
 	switch ( v1->Type()->Tag() ) {
 	case TYPE_VECTOR:
-		if ( ! v1->AsVectorVal()->Assign(v2, v, op) )
+		{
+		const ListVal *lv = v2->AsListVal();
+
+		if ( lv->Length() > 1 )
+			{
+			int len = v1->AsVectorVal()->Size();
+			bro_int_t first = get_slice_index(lv->Index(0)->CoerceToInt(), len);
+			bro_int_t last = get_slice_index(lv->Index(1)->CoerceToInt(), len);
+			int slice_length = last - first;
+
+			const VectorVal *v_vect = v->AsVectorVal();
+			if ( slice_length != v_vect->Size())
+				RuntimeError("vector being assigned to slice does not match size of slice");
+			else if ( slice_length >= 0 )
+				{
+				for ( int idx = first; idx < last; idx++ )
+					v1->AsVectorVal()->Assign(idx, v_vect->Lookup(idx - first)->Ref(), op);
+				}
+			}
+		else if ( !v1->AsVectorVal()->Assign(v2, v, op))
 			{
 			if ( v )
 				{
@@ -3216,6 +3235,7 @@ void IndexExpr::Assign(Frame* f, Val* v, Opcode op)
 				RuntimeErrorWithCallStack("assignment failed with null value");
 			}
 		break;
+		}
 
 	case TYPE_TABLE:
 		if ( ! v1->AsTableVal()->Assign(v2, v, op) )
diff --git a/testing/btest/Baseline/language.vector/out b/testing/btest/Baseline/language.vector/out
index 9e12403ef7..cfd9b75413 100644
--- a/testing/btest/Baseline/language.vector/out
+++ b/testing/btest/Baseline/language.vector/out
@@ -63,3 +63,5 @@ slicing (PASS)
 slicing (PASS)
 slicing (PASS)
 slicing (PASS)
+slicing assignment (PASS)
+slicing assignment (PASS)
diff --git a/testing/btest/language/vector.zeek b/testing/btest/language/vector.zeek
index 04218eb023..e8b3f68e76 100644
--- a/testing/btest/language/vector.zeek
+++ b/testing/btest/language/vector.zeek
@@ -175,4 +175,8 @@ event zeek_init()
 	test_case( "slicing", all_set(v17[:2] == vector( 1, 2 )) );
 	test_case( "slicing", all_set(v17[2:] == vector( 3, 4, 5 )) );
 	test_case( "slicing", all_set(v17[:] == v17) );
+	v17[0:1] = vector(6);
+	test_case( "slicing assignment", all_set(v17 == vector(6, 2, 3, 4, 5)) );
+	v17[2:4] = vector(7, 8);
+	test_case( "slicing assignment", all_set(v17 == vector(6, 2, 7, 8, 5)) );
 }