CrossFade: use negative value for invalid mixramp_delay

src/CrossFade.cxx

@@ -108,7 +108,7 @@ CrossFadeSettings::Calculate(float total_time,
 
 	chunks_f = (float)af.GetTimeToSize() / (float)CHUNK_SIZE;
 
-	if (std::isnan(mixramp_delay) || !mixramp_start || !mixramp_prev_end) {
+	if (mixramp_delay <= 0 || !mixramp_start || !mixramp_prev_end) {
 		chunks = (chunks_f * duration + 0.5);
 	} else {
 		/* Calculate mixramp overlap. */

src/CrossFade.hxx

@@ -22,8 +22,6 @@
 
 #include "Compiler.h"
 
-#include <cmath>
-
 struct AudioFormat;
 
 struct CrossFadeSettings {
@@ -35,14 +33,15 @@ struct CrossFadeSettings {
 	float mixramp_db;
 
 	/**
-	 * The configured MixRapm delay [s].
+	 * The configured MixRapm delay [s].  A non-positive value
+	 * disables MixRamp.
 	 */
 	float mixramp_delay;
 
 	CrossFadeSettings()
 		:duration(0),
 		 mixramp_db(0),
-		 mixramp_delay(std::nanf(""))
+		 mixramp_delay(-1)
 	{}
 
 

src/PlayerThread.cxx

@@ -779,7 +779,7 @@ Player::PlayNextChunk()
 						  other_chunk->tag);
 			other_chunk->tag = nullptr;
 
-			if (std::isnan(pc.cross_fade.mixramp_delay)) {
+			if (pc.cross_fade.mixramp_delay <= 0) {
 				chunk->mix_ratio = ((float)cross_fade_position)
 					     / cross_fade_chunks;
 			} else {