fix(lua): regression with `print()` in headless mode

This is a bunch of hacks so we can override msg_puts_printf specifically
while still allowing redirecting and "normal" message flow to happen,
as this still has observable side-effects (even with no screen attached,
screenstring() is still valid..)

fixes #42218

1 files changed, 7 insertions, 11 deletions

diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index a0b982ab0f..d076e53062 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -1119,17 +1119,13 @@ static void nlua_common_free_all_mem(lua_State *lstate)
 static void nlua_print_event(void **argv)
 {
   msg_ext_no_fast();
-  if (msg_use_printf() && on_print.type == kCallbackNone) {
-    msg_start();  // flush incomplete message
-    printf("%.*s\n", (int)(intptr_t)argv[1] - 1, (char *)argv[0]);
-    xfree(argv[0]);
-  } else {
-    HlMessage msg = KV_INITIAL_VALUE;
-    HlMessageChunk chunk = { { .data = argv[0], .size = (size_t)(intptr_t)argv[1] - 1 }, 0 };
-    kv_push(msg, chunk);
-    bool needs_clear = false;
-    msg_multihl(NIL, msg, "lua_print", true, false, NULL, &needs_clear);
-  }
+  bool raw = msg_use_printf() && !redirecting() && on_print.type == kCallbackNone;
+
+  HlMessage msg = KV_INITIAL_VALUE;
+  HlMessageChunk chunk = { { .data = argv[0], .size = (size_t)(intptr_t)argv[1] - 1 }, 0 };
+  kv_push(msg, chunk);
+  bool needs_clear = false;
+  msg_multihl(NIL, msg, "lua_print", true, false, NULL, &needs_clear, raw);
 }
 
 /// Implements Lua print() as a Nvim message.