diff -Naur --no-dereference ceph-14.2.1.orig/src/common/buffer.cc ceph-14.2.1/src/common/buffer.cc
--- ceph-14.2.1.orig/src/common/buffer.cc	2019-04-25 20:15:48.000000000 +0200
+++ ceph-14.2.1/src/common/buffer.cc	2019-07-12 14:58:21.047996778 +0200
@@ -730,7 +730,7 @@
     : iterator_impl<is_const>(i.bl, i.off, i.p, i.p_off) {}
 
   template<bool is_const>
-  void buffer::list::iterator_impl<is_const>::advance(unsigned o)
+  void buffer::list::iterator_impl<is_const>::advance(unsigned int o)
   {
     //cout << this << " advance " << o << " from " << off
     //     << " (p_off " << p_off << " in " << p->length() << ")"
diff -Naur --no-dereference ceph-14.2.1.orig/src/include/buffer.h ceph-14.2.1/src/include/buffer.h
--- ceph-14.2.1.orig/src/include/buffer.h	2019-04-25 20:15:48.000000000 +0200
+++ ceph-14.2.1/src/include/buffer.h	2019-07-12 14:58:00.170669724 +0200
@@ -736,8 +736,8 @@
       }
 
       void advance(int o) = delete;
-      void advance(unsigned o);
-      void advance(size_t o) { advance(static_cast<unsigned>(o)); }
+      void advance(unsigned int o);
+      void advance(size_t o) { advance(static_cast<unsigned int>(o)); }
       void seek(unsigned o);
       char operator*() const;
       iterator_impl& operator++();