tests: Improve comment in 'txinfo-many-output-formats.sh'

* t/txinfo-many-output-formats.sh: Explain why AM_MAKEINFOFLAGS is set
with an invalid option.

diff --git a/t/txinfo-many-output-formats.sh b/t/txinfo-many-output-formats.sh
index af58964f5594bfc5e40e2af62f7c571ea4c72d74..978417e603e2abee69fc23aafa3c0c0311345161 100644 (file)
--- a/t/txinfo-many-output-formats.sh
+++ b/t/txinfo-many-output-formats.sh
@@ -128,7 +128,8 @@ test ! -e sub/main2.html
 test ! -e rec/main3.html
 
 # Make sure AM_MAKEINFOHTMLFLAGS is supported, and override AM_MAKEINFO.
-
+# Ensure that MAKEINFOFLAGS is not used for the following targets by using an
+# invalid option.
 cp $srcdir/Makefile.am $srcdir/Makefile.sav
 cat >> $srcdir/Makefile.am <<'EOF'
 AM_MAKEINFOHTMLFLAGS = --no-headers --no-split