From f3c86541b6dcee54f62785abe8394120b06e366b Mon Sep 17 00:00:00 2001
From: Valerij Maljulin <valerij.maljulin@gmail.com>
Date: Nov 20 2018 09:45:17 +0000
Subject: Do not retreive rpm info if there is an empty rpm list.

Fixes #1078

Signed-off-by: Valerij Maljulin <vmaljuli@redhat.com>

---

diff --git a/module_build_service/builder/MockModuleBuilder.py b/module_build_service/builder/MockModuleBuilder.py
index 355b937..2f912c1 100644
--- a/module_build_service/builder/MockModuleBuilder.py
+++ b/module_build_service/builder/MockModuleBuilder.py
@@ -178,26 +178,27 @@ class MockModuleBuilder(GenericBuilder):
                      for f in os.listdir(self.resultsdir)
                      if f.endswith(".rpm")]
 
-        output = subprocess.check_output(['rpm',
-                                          '--queryformat',
-                                          '%{NAME} %{EPOCHNUM} %{VERSION} %{RELEASE} %{ARCH}\n',
-                                          '-qp'] + rpm_files,
-                                         cwd=self.resultsdir,
-                                         universal_newlines=True)
-        nevras = output.strip().split('\n')
-        if len(nevras) != len(rpm_files):
-            raise RuntimeError("rpm -qp returned an unexpected number of lines")
-
-        for rpm_file, nevra in zip(rpm_files, nevras):
-            name, epoch, version, release, arch = nevra.split()
-
-            if m1.last_batch_id() == m1.batch:
-                # If RPM is filtered-out, do not add it to artifacts list.
-                if name in m1_mmd.get_rpm_filter().get():
-                    continue
-
-            pkglist_f.write(rpm_file + '\n')
-            artifacts.add('{}-{}:{}-{}.{}'.format(name, epoch, version, release, arch))
+        if rpm_files:
+            output = subprocess.check_output(['rpm',
+                                              '--queryformat',
+                                              '%{NAME} %{EPOCHNUM} %{VERSION} %{RELEASE} %{ARCH}\n',
+                                              '-qp'] + rpm_files,
+                                             cwd=self.resultsdir,
+                                             universal_newlines=True)
+            nevras = output.strip().split('\n')
+            if len(nevras) != len(rpm_files):
+                raise RuntimeError("rpm -qp returned an unexpected number of lines")
+
+            for rpm_file, nevra in zip(rpm_files, nevras):
+                name, epoch, version, release, arch = nevra.split()
+
+                if m1.last_batch_id() == m1.batch:
+                    # If RPM is filtered-out, do not add it to artifacts list.
+                    if name in m1_mmd.get_rpm_filter().get():
+                        continue
+
+                pkglist_f.write(rpm_file + '\n')
+                artifacts.add('{}-{}:{}-{}.{}'.format(name, epoch, version, release, arch))
 
         pkglist_f.close()
         m1_mmd.set_rpm_artifacts(artifacts)
diff --git a/tests/test_builder/test_mock.py b/tests/test_builder/test_mock.py
index 5ca883e..2c620f9 100644
--- a/tests/test_builder/test_mock.py
+++ b/tests/test_builder/test_mock.py
@@ -159,3 +159,19 @@ class TestMockModuleBuilder:
                 pkglist = fd.read().strip()
                 rpm_names = [kobo.rpmlib.parse_nvr(rpm)["name"] for rpm in pkglist.split('\n')]
                 assert "ed" in rpm_names
+
+    @mock.patch("module_build_service.conf.system", new="mock")
+    def test_createrepo_empty_rmp_list(self, *args):
+        with make_session(conf) as session:
+            module = self._create_module_with_filters(session, 3, koji.BUILD_STATES['COMPLETE'])
+
+            builder = MockModuleBuilder("mcurlej", module, conf, module.koji_tag,
+                                        module.component_builds)
+            builder.resultsdir = self.resultdir
+            rpms = []
+            with mock.patch("os.listdir", return_value=rpms):
+                builder._createrepo()
+
+            with open(os.path.join(self.resultdir, "pkglist"), "r") as fd:
+                pkglist = fd.read().strip()
+                assert not pkglist