diff --git a/libs/gib/gib_builtin.c b/libs/gib/gib_builtin.c
index 43b720048..fa972cb57 100644
--- a/libs/gib/gib_builtin.c
+++ b/libs/gib/gib_builtin.c
@@ -353,13 +353,13 @@ GIB_Slice_f (void)
 {
 	dstring_t *ret;
 	int start, end, len;
-	if (GIB_Argc() != 4)
-		GIB_USAGE ("string start end");
+	if (GIB_Argc() < 3 || GIB_Argc() > 4)
+		GIB_USAGE ("string start [end]");
 	else {
 		len = strlen (GIB_Argv(1));
 		start = atoi (GIB_Argv(2));
-		end = atoi (GIB_Argv(3));
-		if (end < 1)
+		end = *GIB_Argv(3) ? atoi (GIB_Argv(3)) : len;
+		if (end < 0)
 			end += len;
 		else if (end > len)
 			end = len;
diff --git a/libs/gib/gib_execute.c b/libs/gib/gib_execute.c
index 70672be37..e2980a950 100644
--- a/libs/gib/gib_execute.c
+++ b/libs/gib/gib_execute.c
@@ -86,16 +86,19 @@ GIB_Execute_Split_Array (cbuf_t *cbuf)
 			if (str[i] == '[') {
 				str[i] = 0;
 				start = atoi (str+i+1);
-				if ((c = strchr (str+i+1, ':')))
-					end = atoi (c+1);
-				else
-					end = start;
+				if ((c = strchr (str+i+1, ':'))) {
+					if (c[1] != ']')
+						end = atoi (c+1);
+					else
+						end = (int) ((unsigned int)~0>>1);
+				} else
+					end = start+1;
 				break;
 			}
 	cbuf->args->argc--;
 	if (!(var = GIB_Var_Get_Complex (&GIB_DATA(cbuf)->locals, &GIB_DATA(cbuf)->globals, str, &i, false)))
 		return;
-	if (end < 1)
+	if (end < 0)
 		end += var->size;
 	else if (end > var->size)
 		end = var->size;
diff --git a/libs/gib/gib_parse.c b/libs/gib/gib_parse.c
index 892ae08c7..c20ee8f7e 100644
--- a/libs/gib/gib_parse.c
+++ b/libs/gib/gib_parse.c
@@ -307,7 +307,8 @@ DONE:
 	*embedded = embs;
 	return nodes;
 ERROR:
-	GIB_Tree_Free_Recursive (nodes);
+	if (nodes)
+		GIB_Tree_Free_Recursive (nodes);
 	gib_parse_error = true;
 	return 0;
 }
@@ -471,7 +472,8 @@ GIB_Parse_Lines (const char *program, unsigned int flags)
 	}
 	return lines;
 ERROR:
-	GIB_Tree_Free_Recursive (lines);
+	if (lines)
+		GIB_Tree_Free_Recursive (lines);
 	return 0;
 }
 
@@ -569,6 +571,7 @@ GIB_Parse_Embedded (const char *program, unsigned int flags, gib_tree_t **embedd
 	return lines;
 ERROR:
 	gib_parse_error = true;
-	GIB_Tree_Free_Recursive (lines);
+	if (lines)
+		GIB_Tree_Free_Recursive (lines);
 	return 0;
 }