Be more formal about quoting in m4 macros

diff --git a/configure.ac b/configure.ac
index 1fbb9752c2b3add322a716b8dd552deb8628419f..a14cbf091ca9857c5856ca51a0025c8a390b2760 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -388,16 +388,16 @@ dnl --- ncurses
 
                        AC_CHECK_HEADERS(ncursesw/ncurses.h,
                                [cf_cv_ncurses_header="ncursesw/ncurses.h"],
-                               AC_CHECK_HEADERS(ncurses/ncurses.h,
+                               [AC_CHECK_HEADERS(ncurses/ncurses.h,
                                        [cf_cv_ncurses_header="ncurses/ncurses.h"],
-                                       AC_CHECK_HEADERS(ncurses.h,
+                                       [AC_CHECK_HEADERS(ncurses.h,
                                                [cf_cv_ncurses_header="ncurses.h"],
-                                               AC_CHECK_HEADERS(curses.h,
+                                               [AC_CHECK_HEADERS(curses.h,
                                                        [cf_cv_ncurses_header="curses.h"],
-                                                       AC_MSG_ERROR(Unable to find ncurses headers)
-                                               )
-                                       )
-                               )
+                                                       [AC_MSG_ERROR([Unable to find ncurses headers])]
+                                               ])
+                                       ])
+                               ])
                        )
                ],)
        ])