[sysprof] tests: add check for buffer contents from save_as()

[Christian Hergert <chergert src gnome org>]

commit 36179e9ab4aeee8e7932a0af5aa31f29db09eb91
Author: Christian Hergert <chergert redhat com>
Date:   Mon May 6 16:19:58 2019 -0700

    tests: add check for buffer contents from save_as()

 tests/test-capture.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
---
diff --git a/tests/test-capture.c b/tests/test-capture.c
index 87b2530..119a857 100644
--- a/tests/test-capture.c
+++ b/tests/test-capture.c
@@ -363,6 +363,28 @@ test_reader_basic (void)
   g_assert (r);
   g_assert (g_file_test ("capture-file.bak", G_FILE_TEST_IS_REGULAR));
 
+  /* make sure contents are equal */
+  {
+    g_autofree gchar *buf1 = NULL;
+    g_autofree gchar *buf2 = NULL;
+    gsize buf1len = 0;
+    gsize buf2len = 0;
+
+    r = g_file_get_contents ("capture-file.bak", &buf1, &buf1len, &error);
+    g_assert_no_error (error);
+    g_assert_true (r);
+
+    r = g_file_get_contents ("capture-file", &buf2, &buf2len, &error);
+    g_assert_no_error (error);
+    g_assert_true (r);
+
+    g_assert_cmpint (buf1len, >, 0);
+    g_assert_cmpint (buf2len, >, 0);
+
+    g_assert_cmpint (buf1len, ==, buf2len);
+    g_assert_true (0 == memcmp (buf1, buf2, buf1len));
+  }
+
   g_clear_pointer (&writer, sp_capture_writer_unref);
   g_clear_pointer (&reader, sp_capture_reader_unref);