Fix all segments checkbox

Author: blazoncek

wled00/data/index.js

@@ -796,11 +796,12 @@ function populateSegments(s)
 	gId('segcont').innerHTML = cn;
 	let noNewSegs = (lowestUnused >= maxSeg);
 	resetUtil(noNewSegs);
+	if (gId('selall')) gId('selall').checked = true;
 	for (var i = 0; i <= lSeg; i++) {
 		updateLen(i);
 		updateTrail(gId(`seg${i}bri`));
 		gId(`segr${i}`).style.display = "none";
-		if (!gId(`seg${i}sel`).checked && gId('selall')) gId('selall').checked = false;
+		if (!gId(`seg${i}sel`).checked && gId('selall')) gId('selall').checked = false; // uncheck if at least one is unselected.
 	}
 	if (segCount < 2) gId(`segd${lSeg}`).style.display = "none";
 	if (!isM && !noNewSegs && (cfg.comp.seglen?parseInt(gId(`seg${lSeg}s`).value):0)+parseInt(gId(`seg${lSeg}e`).value)<ledCount) gId(`segr${lSeg}`).style.display = "inline";