@@ -1,9 +1,21 @@
-# $NetBSD: varmod-quote.mk,v 1.2 2020/08/16 14:25:16 rillig Exp $
+# $NetBSD: varmod-quote.mk,v 1.3 2020/10/29 19:07:45 rillig Exp $
 #
 # Tests for the :Q variable modifier, which quotes the variable value
 # to be used in a shell program.
 
-# TODO: Implementation
+# Any characters that might be interpreted by the shell are escaped.
+# The set of escaped characters is the same, no matter which shell (sh, csh,
+# ksh) is in effect.
+.if ${:Ua b c:Q} != "a\\ b\\ c"
+.  error
+.endif
+
+# The quote modifier only applies if the whole modifier name is "Q".
+# There is no "Qshell" or "Qawk" or "Qregex" or even "Qhtml" variant.
+# All strings except the plain "Q" are interpreted as SysV modifier.
+.if ${:Ua.Qshell:Qshell=replaced} != "a.replaced"
+.  error
+.endif
 
 all:
 	@:;