lua: allow changing the displayed file of a window

Change the file displayed in a window by writing the new file name
to the window's file member.

This is useful to change the displayed file during events.
Using the edit command during an event caused by a pervious edit
command causes a double free.

1 files changed, 6 insertions, 0 deletions

diff --git a/vis-lua.c b/vis-lua.c
index a62daf8..ca36d2d 100644
--- a/vis-lua.c
+++ b/vis-lua.c
@@ -2019,6 +2019,12 @@ static int window_newindex(lua_State *L) {
 			}
 			lua_pop(L, 1);
 			return ret;
+		} else if (strcmp(key, "file") == 0 && lua_isstring(L, 3)) {
+			const char* filename = lua_tostring(L, 3);
+			if (!vis_window_change_file(win, filename)) {
+				return luaL_argerror(L, 3, "failed to open");
+			}
+			return 0;
 		}
 	}