NULL-check before freeing set in _parse_modulemd_filters

Fixes: #26

Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>

modulemd/modulemd-yaml-parser-modulemd.c

@@ -1361,7 +1361,7 @@ _parse_modulemd_filters (ModulemdModule *module,
 
 error:
   yaml_event_delete (&event);
-  g_object_unref (set);
+  g_clear_pointer (&set, g_object_unref);
 
   g_debug ("TRACE: exiting _parse_modulemd_filters");
   return result;

modulemd/test-modulemd-regressions.c

@@ -141,6 +141,27 @@ modulemd_regressions_issue25 (RegressionFixture *fixture,
                    "%my_macro 1");
 }
 
+
+static void
+modulemd_regressions_issue26 (RegressionFixture *fixture,
+                              gconstpointer user_data)
+{
+  gchar *yaml_path;
+  ModulemdModule *module = NULL;
+
+  /* This would segfault because we weren't checking for NULL
+   * prior to attempting to free the simpleset in
+   * _parse_modulemd_filters
+   */
+  yaml_path = g_strdup_printf ("%s/test_data/issue26.yaml",
+                               g_getenv ("MESON_SOURCE_ROOT"));
+  module = modulemd_module_new_from_file (yaml_path);
+  g_assert_nonnull (module);
+
+  g_object_unref (module);
+}
+
+
 int
 main (int argc, char *argv[])
 {
@@ -192,5 +213,12 @@ main (int argc, char *argv[])
               modulemd_regressions_issue25,
               NULL);
 
+  g_test_add ("/modulemd/regressions/issue26",
+              RegressionFixture,
+              NULL,
+              NULL,
+              modulemd_regressions_issue26,
+              NULL);
+
   return g_test_run ();
 }

test_data/issue26.yaml

@@ -0,0 +1,61 @@
+data:
+  api:
+    rpms: [tangerine, perl-Tangerine]
+  components:
+    rpms:
+      perl-List-Compare: {cache: 'http://pkgs.fedoraproject.org/repo/pkgs/perl-List-Compare',
+        rationale: A dependency of tangerine., ref: 76f9d8c8e87eed0aab91034b01d3d5ff6bd5b4cb,
+        repository: 'git://pkgs.fedoraproject.org/rpms/perl-List-Compare'}
+      perl-Tangerine: {cache: 'http://pkgs.fedoraproject.org/repo/pkgs/perl-Tangerine',
+        rationale: Provides API for this module and is a dependency of tangerine.,
+        ref: 4ceea43add2366d8b8c5a622a2fb563b625b9abf, repository: 'git://pkgs.fedoraproject.org/rpms/perl-Tangerine'}
+      tangerine: {buildorder: 10, cache: 'http://pkgs.fedoraproject.org/repo/pkgs/tangerine',
+        rationale: Provides API for this module., ref: fbed359411a1baa08d4a88e0d12d426fbf8f602c,
+        repository: 'git://pkgs.fedoraproject.org/rpms/tangerine'}
+  dependencies:
+    buildrequires:
+      zebra: stripes
+      base-runtime: master
+      fluffy: slippers
+    requires:
+      fidget: spinner
+      base-runtime: master
+      silly: puddy
+      glass: water
+  description: This module demonstrates how to write simple modulemd files And can
+    be used for testing the build and release pipeline.
+  filter: {}
+  license:
+    module: [MIT]
+  name: testmodule
+  profiles:
+    default:
+      rpms: [tangerine]
+  references: {community: 'https://fedoraproject.org/wiki/Modularity', documentation: 'https://fedoraproject.org/wiki/Fedora_Packaging_Guidelines_for_Modules',
+    tracker: 'https://taiga.fedorainfracloud.org/project/modularity'}
+  stream: master
+  summary: A test module in all its beautiful beauty
+  version: 20170109091357
+  xmd:
+    mbs:
+      buildrequires:
+        zebra:
+          ref: 08f8671f5925ecbd7c55d83e8368dd0be81ef8ed
+        base-runtime:
+          ref: ae993ba84f4bce554471382ccba917ef16265f11
+        fluffy:
+          ref: ea83325b231f64c575ea104bb698e9d43b80469a
+      requires:
+        fidget:
+          ref: 5aa32bd61aadaec8295ef90f79daaf190e387509
+        base-runtime:
+          ref: ae993ba84f4bce554471382ccba917ef16265f11
+        silly:
+          ref: 0e2a1f9246118180d61aad731923ebd85154bc6e
+        glass:
+          ref: ea8753e832974dd5b0d95cd6bb7d26727d2ba742
+      commit: 7fea453bc362cc8e5aa41e129e689baea853653d
+      scmurl: git://pkgs.stg.fedoraproject.org/modules/testmodule.git?#7fea453
+document: modulemd
+version: 1
+