File update-alternatives-slavetomaster.patch of Package dpkg

Index: dpkg-1.19.0.5/utils/update-alternatives.c
===================================================================
--- dpkg-1.19.0.5.orig/utils/update-alternatives.c
+++ dpkg-1.19.0.5/utils/update-alternatives.c
@@ -1796,7 +1796,10 @@ alternative_prepare_install(struct alter
 		/* Drop unused slave. */
 		fn = xasprintf("%s/%s", altdir, sl->name);
 		if (alternative_path_can_remove(sl->link))
-			alternative_add_commit_op(a, OPCODE_RM, sl->link, NULL);
+			if (strcmp(sl->link, a->master_link))
+				alternative_add_commit_op(a, OPCODE_RM, sl->link, NULL);
+			else
+				warning("not removing %s, now master", a->master_link);
 		else
 			warning(_("not removing %s since it's not a symlink"),
 			        sl->link);