From b1b714bb5c36470a31bc885304bf116b71d1c804 Mon Sep 17 00:00:00 2001
From: Dmitry Karasik <dmitry.karasik@teliacompany.com>
Date: Mon, 22 Jul 2024 20:39:08 +0200
Subject: [PATCH] minor optimization

---
 img/utils.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/img/utils.c b/img/utils.c
index 323de35a..3924f365 100644
--- a/img/utils.c
+++ b/img/utils.c
@@ -159,8 +159,11 @@ void
 img_multiply_alpha( Byte * src, Byte * alpha, int alpha_step, Byte * dst, int bytes)
 {
 	if ( alpha_step == 0 ) {
-		while (bytes--)
-			*(dst++) = *(src++) * *(alpha  ) / 255.0 + .5;
+		if ( *alpha < 255 ) {
+			while (bytes--)
+				*(dst++) = *(src++) * *(alpha  ) / 255.0 + .5;
+		} else if ( src != dst )
+			memcpy( dst, src, bytes);
 	} else {
 		while (bytes--)
 			*(dst++) = *(src++) * *(alpha++) / 255.0 + .5;