From 785de41a92dcd45a71c322bafa8af737bb1eb7aa Mon Sep 17 00:00:00 2001
From: Ben Harris <bjh21@bjh21.me.uk>
Date: Wed, 9 Aug 2023 11:42:51 +0100
Subject: [PATCH] Appropriately generate MOVE_NO_EFFECT from '\b' in Guess

This is the case that I care about for KaiOS.
---
 guess.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/guess.c b/guess.c
index 2796bca..5c5f941 100644
--- a/guess.c
+++ b/guess.c
@@ -943,9 +943,12 @@ static char *interpret_move(const game_state *from, game_ui *ui,
             ui->peg_cur++;
         ret = MOVE_UI_UPDATE;
     } else if (button == 'D' || button == 'd' || button == '\b') {
-        ui->display_cur = true;
-        set_peg(&from->params, ui, ui->peg_cur, 0);
-        ret = MOVE_UI_UPDATE;
+        if (!ui->display_cur || ui->curr_pegs->pegs[ui->peg_cur] != 0) {
+            ui->display_cur = true;
+            set_peg(&from->params, ui, ui->peg_cur, 0);
+            ret = MOVE_UI_UPDATE;
+        } else
+            ret = MOVE_NO_EFFECT;
     } else if (button == CURSOR_SELECT2) {
         if (ui->peg_cur == from->params.npegs)
             return NULL;