[glib: 1/2] gutils test: Don't assume that every Unix OS implements os-release(5)

[Philip Withnall <pwithnall src gnome org>]

commit f9a1970a0f5a3f3fa9c002df061889e2c026624f
Author: Simon McVittie <smcv collabora com>
Date:   Wed Oct 9 14:11:08 2019 +0100

    gutils test: Don't assume that every Unix OS implements os-release(5)
    
    os-release(5) is widely implemented on Linux, but not necessarily
    ubiquitous: unusual or minimal Linux distributions might not have it.
    It could in principle be implemented by any other Unix OS, but in
    practice this has not yet happened.
    
    Closes: https://gitlab.gnome.org/GNOME/glib/issues/1906
    Fixes: 349318e8 "gutils: Add g_get_os_info()"
    Signed-off-by: Simon McVittie <smcv collabora com>

 glib/tests/utils.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)
---
diff --git a/glib/tests/utils.c b/glib/tests/utils.c
index 7dbfb1e47..ce956a270 100644
--- a/glib/tests/utils.c
+++ b/glib/tests/utils.c
@@ -520,15 +520,30 @@ test_desktop_special_dir (void)
 static void
 test_os_info (void)
 {
-#if defined (G_OS_UNIX) || defined (G_OS_WIN32)
   gchar *name;
+  gchar *contents = NULL;
 
+  /* Whether this is implemented or not, it must not crash */
   name = g_get_os_info (G_OS_INFO_KEY_NAME);
-  g_assert (name != NULL);
-  g_free (name);
+  g_test_message ("%s: %s",
+                  G_OS_INFO_KEY_NAME,
+                  name == NULL ? "(null)" : name);
+
+#if defined (G_OS_WIN32) || defined (__APPLE__)
+  /* These OSs have a special case so NAME should always succeed */
+  g_assert_nonnull (name);
+#elif defined (G_OS_UNIX)
+  if (g_file_get_contents ("/etc/os-release", &contents, NULL, NULL) ||
+      g_file_get_contents ("/usr/lib/os-release", &contents, NULL, NULL))
+    g_assert_nonnull (name);
+  else
+    g_test_skip ("os-release(5) API not implemented on this platform");
 #else
   g_test_skip ("g_get_os_info() not supported on this platform");
 #endif
+
+  g_free (name);
+  g_free (contents);
 }
 
 static gboolean