--- a/tests/test-repo-compengines.t	Wed Feb 19 13:39:00 2020 +0530
+++ b/tests/test-repo-compengines.t	Wed Feb 19 17:30:04 2020 +0100
@@ -22,10 +22,15 @@
 Unknown compression engine to format.compression aborts
 
   $ hg --config format.revlog-compression=unknown init unknown
-  abort: compression engine unknown defined by format.revlog-compression not available
+  abort: compression engines "unknown" defined by format.revlog-compression not available
   (run "hg debuginstall" to list available compression engines)
   [255]
 
+unknown compression engine in a list with known one works fine
+
+  $ hg --config format.revlog-compression=zlib,unknown init zlib-before-unknow
+  $ hg --config format.revlog-compression=unknown,zlib init unknown-before-zlib
+
 A requirement specifying an unknown compression engine results in bail
 
   $ hg init unknownrequirement