configure.ac: Allow for custom docbook2x-man command

Example:
./configure DOCBOOK_TO_MAN=/bin/true

diff --git a/expat/configure.ac b/expat/configure.ac
index 1f7deded07d2a502588571b2df8c06177f1ddf4e..1f7495efe5eac72138dde86af8c0f4a42e9f817d 100644 (file)
--- a/expat/configure.ac
+++ b/expat/configure.ac
@@ -234,7 +234,7 @@ AC_ARG_WITH([docbook],
   [],
   [with_docbook=check])
 
-DOCBOOK_TO_MAN=
+AC_ARG_VAR([DOCBOOK_TO_MAN], [docbook2x-man command])
 AS_IF([test "x$with_docbook" != xno],
   [AC_CHECK_PROGS([DOCBOOK_TO_MAN], [docbook2x-man docbook2man],
   [if test "x$with_docbook" != xcheck; then