macro: Fix crash for !QUOTE of a quoted string.

[pspp] / doc / flow-control.texi

diff --git a/doc/flow-control.texi b/doc/flow-control.texi
index d3235612b9fddb04ec0e42a1c697ae3e4afd0e17..23539bcfb67e24b420f4b6669a95172a05178051 100644 (file)
--- a/doc/flow-control.texi
+++ b/doc/flow-control.texi
@@ -578,6 +578,8 @@ Expands to a number token representing the number of characters in
 @deffn {Macro Function} !NULL
 Expands to an empty character sequence.
 
+@c Keep these examples in sync with the test for !NULL in
+@c tests/language/control/define.at:
 @example
 !NULL                        @expansion{} @r{empty}
 !QUOTE(!NULL)                @expansion{} ''
@@ -596,6 +598,8 @@ to the string's contents, with the quotes removed and any doubled
 quote marks reduced to singletons.  If the argument was not a quoted
 string, @code{!UNQUOTE} expands to the argument unchanged.
 
+@c Keep these examples in sync with the test for !QUOTE and !UNQUOTE in
+@c tests/language/control/define.at:
 @example
 !QUOTE(123.0)                @expansion{} '123.0'
 !QUOTE( 123 )                @expansion{} '123'