Commit 43e4dbfc7 for imagemagick.org

commit 43e4dbfc7a80dac4adeeae4999a757746ec25ab2
Author: Dirk Lemstra <dirk@lemstra.org>
Date:   Sun Mar 29 18:06:47 2026 +0200

    Restored old CopyAlpha behavior.

diff --git a/MagickCore/composite.c b/MagickCore/composite.c
index 441c09877..4a88a946f 100644
--- a/MagickCore/composite.c
+++ b/MagickCore/composite.c
@@ -2592,7 +2592,10 @@ MagickExport MagickBooleanType CompositeImage(Image *image,
               }
               case CopyAlphaCompositeOp:
               {
-                pixel=Si;
+                if (source_image->alpha_trait == UndefinedPixelTrait)
+                  pixel=Si;
+                else
+                  pixel=(double) QuantumRange*Sa;
                 break;
               }
               case BlurCompositeOp: