1 files changed, 9 insertions, 0 deletions
diff --git a/test/fs.py b/test/fs.py
index a025ec47..8047273d 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -836,6 +836,15 @@ def odd_paths(binary):
                         pass
                     assert client.read('/index'), (where, line)
             client.write('/ctl', b'DumpDir\n')
+            # A theme file that is not there, or no theme, fails the write.
+            (root / 'bad.zon').write_bytes(b'.{ .nonsense = 1 }')
+            for line, why in ((f'ThemeFile {root}/missing.zon', 'theme file'), (f'ThemeFile {root}/bad.zon', 'theme file'),
+                              ('ThemeFile notes.txt', 'a theme file is a .zon')):
+                try:
+                    client.write('/ctl', (line + '\n').encode())
+                    raise AssertionError(f'{line} was taken')
+                except OSError as refused:
+                    assert why in str(refused), (line, refused)
 
 
 def cut_writes(binary):