From 8e5baf5ca7ed6d56fe379a7e46c1eea1d20f45c6 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Wed, 16 Oct 2019 21:02:45 +0000
Subject: [PATCH] Detect whether zchunk (zck) is available at build time

We don't *actually* use this ourself, but librepo does, and libdnf gets confused
if librepo doesn't support it.  This is the case in RHEL8 currently.

Basically what breaks is trying to use the Fedora EPEL repo (has zchunk metadata)
on RHEL CoreOS.  And we have a test in kola that does this today.
---
 configure.ac                 |  5 +++++
 packaging/rpm-ostree.spec.in | 12 ++++++++++++
 src/libpriv/rpmostree-core.c |  7 +++++++
 3 files changed, 24 insertions(+)

diff --git a/configure.ac b/configure.ac
index a0c5cce4..7fdadb4d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -129,6 +129,11 @@ AS_IF([pkg-config --atleast-version=3.3.3 libarchive],
 dnl This is the current version in Fedora 25.
 AS_IF([pkg-config --atleast-version=4.14.2 rpm], [], [AC_MSG_ERROR([librpm 4.14.2 required])])
 
+dnl We don't *actually* use this ourself, but librepo does, and libdnf gets confused
+dnl if librepo doesn't support it.
+AS_IF([pkg-config --exists zck],
+  [AC_DEFINE([HAVE_ZCHUNK], 1, [Define if we have zchunk])])
+
 AC_PATH_PROG([XSLTPROC], [xsltproc])
 
 GLIB_TESTS
diff --git a/packaging/rpm-ostree.spec.in b/packaging/rpm-ostree.spec.in
index e2468d60..aa7465c0 100644
--- a/packaging/rpm-ostree.spec.in
+++ b/packaging/rpm-ostree.spec.in
@@ -22,6 +22,15 @@ BuildRequires: rust
 BuildRequires: rust-toolset
 %endif
 
+# RHEL8 doesn't ship zchunk today.  See also the comments
+# in configure.ac around this as libdnf/librepo need to be in
+# sync, and today we bundle libdnf but not librepo.
+%if 0%{?rhel}
+%bcond_with zchunk
+%else
+%bcond_without zchunk
+%endif
+
 # For the autofiles bits below
 BuildRequires: /usr/bin/python3
 # We always run autogen.sh
@@ -74,6 +83,9 @@ BuildRequires:  pkgconfig(json-c)
 BuildRequires:  pkgconfig(cppunit)
 BuildRequires:  pkgconfig(sqlite3)
 BuildRequires:  pkgconfig(smartcols)
+%if %{with zchunk}
+BuildRequires:  pkgconfig(zck) >= 0.9.11
+%endif
 BuildRequires:  gpgme-devel
 
 Requires:       libmodulemd1%{?_isa} >= %{libmodulemd_version}
diff --git a/src/libpriv/rpmostree-core.c b/src/libpriv/rpmostree-core.c
index 20a75fe5..048648ba 100644
--- a/src/libpriv/rpmostree-core.c
+++ b/src/libpriv/rpmostree-core.c
@@ -431,6 +431,13 @@ rpmostree_context_new_system (OstreeRepo   *repo,
   dnf_context_set_check_disk_space (self->dnfctx, FALSE);
   dnf_context_set_check_transaction (self->dnfctx, FALSE);
 
+  /* Hack until libdnf+librepo know how to better negotaiate zchunk.
+   * see also the bits in configure.ac that define HAVE_ZCHUNK
+   **/
+#ifndef HAVE_ZCHUNK
+  dnf_context_set_zchunk (self->dnfctx, FALSE);
+#endif
+
   return self;
 }