From: H.G. Muller <h.g.muller@hccnet.nl>
Date: Fri, 5 Feb 2010 19:36:50 +0000 (+0100)
Subject: Fix highlighting bug in XBoard
X-Git-Tag: v4.4.3.20100220~15
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=59d1333eb463402beb7ef0e0606d99245eda8af4;p=xboard.git

Fix highlighting bug in XBoard

The from-square was drawn before the to-square was erased, which led to
a missing highlight line if they shared an edge or corner.
---

diff --git a/xboard.c b/xboard.c
index 4a47133..d4d8369 100644
--- a/xboard.c
+++ b/xboard.c
@@ -4549,14 +4549,18 @@ SetHighlights(fromX, fromY, toX, toY)
 	if (hi1X >= 0 && hi1Y >= 0) {
 	    drawHighlight(hi1X, hi1Y, lineGC);
 	}
+    } // [HGM] first erase both, then draw new!
+    if (hi2X != toX || hi2Y != toY) {
+	if (hi2X >= 0 && hi2Y >= 0) {
+	    drawHighlight(hi2X, hi2Y, lineGC);
+	}
+    }
+    if (hi1X != fromX || hi1Y != fromY) {
 	if (fromX >= 0 && fromY >= 0) {
 	    drawHighlight(fromX, fromY, highlineGC);
 	}
     }
     if (hi2X != toX || hi2Y != toY) {
-	if (hi2X >= 0 && hi2Y >= 0) {
-	    drawHighlight(hi2X, hi2Y, lineGC);
-	}
 	if (toX >= 0 && toY >= 0) {
 	    drawHighlight(toX, toY, highlineGC);
 	}