From: Simon Tatham <anakin@pobox.com>
Date: Sun, 25 Feb 2007 13:00:58 +0000 (+0000)
Subject: Don't create an undo-chain entry for a move with no effect.
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=a7408203eb9a3720cd9a7828253de844faf3ce44;p=sgt-puzzles.git

Don't create an undo-chain entry for a move with no effect.

[originally from svn r7333]
---

diff --git a/filling.c b/filling.c
index ac5b6d9..82efcca 100644
--- a/filling.c
+++ b/filling.c
@@ -962,9 +962,13 @@ static char *interpret_move(game_state *state, game_ui *ui, game_drawstate *ds,
     {
         const int i = w*ui->y + ui->x;
         char buf[64];
-        sprintf(buf, "%d_%d", i, button);
         ui->x = ui->y = -1;
-        return dupstr(buf);
+	if (state->board[i] == button) {
+	    return "";		       /* no change - just update ui */
+	} else {
+	    sprintf(buf, "%d_%d", i, button);
+	    return dupstr(buf);
+	}
     }
 }