configure: Make the DJVU_FONT_SOURCE configurable with --with-dejavufont=FILE

Font might be located in different location, the default font might
not be available on all systems or other font might be preferred.

Signed-off-by: Richard Marko <srk@48.io>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

configure.ac

@@ -1796,8 +1796,6 @@ CPPFLAGS="$SAVED_CPPFLAGS"
 LDFLAGS="$SAVED_LDFLAGS"
 
 
-DJVU_FONT_SOURCE=
-
 starfield_excuse=
 
 AC_ARG_ENABLE([grub-themes],
@@ -1811,7 +1809,13 @@ if test x"$starfield_excuse" = x && test x"$enable_build_grub_mkfont" = xno ; th
   starfield_excuse="No build-time grub-mkfont"
 fi
 
-if test x"$starfield_excuse" = x; then
+AC_ARG_WITH([dejavufont],
+            AS_HELP_STRING([--with-dejavufont=FILE],
+                           [set the DejeVu source [[guessed]]]))
+
+if test "x$with_dejavufont" = x; then
+  # search in well-known directories
+  if test x"$starfield_excuse" = x; then
      for ext in pcf pcf.gz bdf bdf.gz ttf ttf.gz; do
        for dir in . /usr/src /usr/share/fonts/X11/misc /usr/share/fonts/truetype/ttf-dejavu /usr/share/fonts/dejavu /usr/share/fonts/truetype; do
           if test -f "$dir/DejaVuSans.$ext"; then
@@ -1824,6 +1828,9 @@ if test x"$starfield_excuse" = x; then
      if test "x$DJVU_FONT_SOURCE" = x; then
        starfield_excuse="No DejaVu found"
      fi
+  fi
+else
+  DJVU_FONT_SOURCE="$with_dejavufont"
 fi
 
 if test x"$enable_grub_themes" = xyes &&  test x"$starfield_excuse" != x; then