diff --git a/tests/test-hybridencode.py b/tests/test-hybridencode.py
new file mode 100755
--- /dev/null
+++ b/tests/test-hybridencode.py
@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+
+from mercurial import store
+
+enc = store.hybridencode # used for fncache repo format
+
+def show(s):
+    print "A = '%s'" % s
+    print "B = '%s'" % enc(s)
+    print
+
+show('data/aux.bla/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c.i')
+
+show('data/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT.i')
+show('data/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider.i')
+show('data/AUX.THE-QUICK-BROWN-FOX-JU:MPS-OVER-THE-LAZY-DOG-THE-QUICK-BROWN-FOX-JUMPS-OVER-THE-LAZY-DOG.TXT.i')
diff --git a/tests/test-hybridencode.py.out b/tests/test-hybridencode.py.out
new file mode 100644
--- /dev/null
+++ b/tests/test-hybridencode.py.out
@@ -0,0 +1,12 @@
+A = 'data/aux.bla/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c.i'
+B = 'data/au~78.bla/bla.aux/pr~6e/_p_r_n/lpt/co~6d3/nu~6c/coma/foo._n_u_l/normal.c.i'
+
+A = 'data/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT.i'
+B = 'dh/au~78/second/x.prn/fourth/fi~3afth/sixth/seventh/eighth/nineth/tenth/loremia20419e358ddff1bf8751e38288aff1d7c32ec05.i'
+
+A = 'data/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider.i'
+B = 'dh/enterpri/openesba/contrib-/corba-bc/netbeans/wsdlexte/src/main/java/org.net7018f27961fdf338a598a40c4683429e7ffb9743.i'
+
+A = 'data/AUX.THE-QUICK-BROWN-FOX-JU:MPS-OVER-THE-LAZY-DOG-THE-QUICK-BROWN-FOX-JUMPS-OVER-THE-LAZY-DOG.TXT.i'
+B = 'dh/au~78.the-quick-brown-fox-ju~3amps-over-the-lazy-dog-the-quick-brown-fox-jud4dcadd033000ab2b26eb66bae1906bcb15d4a70.i'
+