test/cli: ensure that there is unmatchedSuppression warning

test/cli/proj-inline-suppress/1.c

@@ -1,2 +1,5 @@
 #include <1.h>
 
+// cppcheck-suppress some_warning_id ; there should be a unmatchedSuppression warning about this
+x;
+

test/cli/test-inline-suppress.py

@@ -15,3 +15,7 @@ def test2():
     assert ret == 0
     assert len(stderr) > 0
 
+def test_unmatched_suppression():
+    ret, stdout, stderr = cppcheck(['--inline-suppr', '--enable=information', '--error-exitcode=1', 'proj-inline-suppress'])
+    assert ret == 1
+    assert 'Unmatched suppression: some_warning_id' in stderr