Commit d8dc77345 for imagemagick.org

commit d8dc77345c76ec4d7b95da8ff4cc12e612b80ec8
Author: Dirk Lemstra <dirk@lemstra.org>
Date:   Sun Jun 7 20:51:54 2026 +0200

    Seek to the start of the blob if possible when opening a custom stream.

diff --git a/MagickCore/blob.c b/MagickCore/blob.c
index 778b85d05..3a1b8ae7b 100644
--- a/MagickCore/blob.c
+++ b/MagickCore/blob.c
@@ -3337,6 +3337,9 @@ MagickExport MagickBooleanType OpenBlob(const ImageInfo *image_info,
     {
       blob_info->type=CustomStream;
       blob_info->custom_stream=image_info->custom_stream;
+      if (blob_info->custom_stream->seeker != (CustomStreamSeeker) NULL)
+        blob_info->custom_stream->seeker(0,SEEK_SET,
+          blob_info->custom_stream->data);
       return(MagickTrue);
     }
   (void) DetachBlob(blob_info);