Commit 2c5232a53 for imagemagick.org

commit 2c5232a5384f601329723c5b19d1dcfa0e8f69d1
Author: Dirk Lemstra <dirk@lemstra.org>
Date:   Sat Nov 14 20:39:51 2026 +0100

    Correct extent calculation (GHSA-qw9c-mq27-w844)

diff --git a/MagickCore/quantum.c b/MagickCore/quantum.c
index ea372b1a8..310569ba7 100644
--- a/MagickCore/quantum.c
+++ b/MagickCore/quantum.c
@@ -334,8 +334,13 @@ MagickExport size_t GetQuantumExtent(const Image *image,
     default: break;
   }
   if (quantum_info->pack == MagickFalse)
-    return((size_t) (channels*image->columns*((quantum_info->depth+7)/8))+
-      (quantum_info->pad*image->columns));
+    {
+      if ((image->columns == 1) && (quantum_type == GrayQuantum) &&
+          (quantum_info->depth == 10))
+        return(4+quantum_info->pad);
+      return((size_t) (channels*image->columns*((quantum_info->depth+7)/8))+
+        (quantum_info->pad*image->columns));
+    }
   return((size_t) ((channels*image->columns*quantum_info->depth+7)/8)+
     (quantum_info->pad*image->columns));
 }