Move various tricky configure logic to their own file

git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@6007 ea778897-0a13-0410-b9d1-a72fbfd435f5

ChangeLog

@@ -4,7 +4,8 @@
    Modernize configure.ac a bit.
  * configure.ac, m4/geany-revision.m4, m4/geany-binreloc.m4,
    m4/geany-gnu-regex.m4, m4/geany-plugins.m4, m4/geany-i18n.m4,
-   m4/geany-mingw.m4, m4/geany-socket.m4, m4/geany-vte.m4:
+   m4/geany-mingw.m4, m4/geany-socket.m4, m4/geany-vte.m4,
+   m4/geany-utils.m4:
    Extract some configure logic to separate files for better
    readability.
 

configure.ac

@@ -42,6 +42,8 @@ AC_CHECK_FUNCS([gethostname ftruncate fgetpos mkstemp strerror strstr])
 
 # autoscan end
 
+GEANY_PREFIX
+GEANY_DOCDIR
 
 # check for SVN revision
 GEANY_CHECK_REVISION([dnl force debug mode for a SVN working copy
@@ -107,19 +109,6 @@ fi
 GEANY_I18N
 
 
-# Set ${datadir}
-if test "x${datadir}" = 'x${prefix}/share' -o "x${datarootdir}" = 'x${prefix}/share'; then
-	if test "x${prefix}" = "xNONE"; then
-		prefix=${ac_default_prefix}
-	fi
-fi
-
-# Set ${docdir} if it is empty
-if test -z "${docdir}"; then
-	docdir='${datadir}/doc/${PACKAGE}'
-	AC_SUBST([docdir])
-fi
-
 GEANY_DATA_DIR=`eval echo ${datarootdir}/geany`
 AC_SUBST([GEANY_DATA_DIR])
 

m4/geany-utils.m4

@@ -0,0 +1,26 @@
+dnl GEANY_PREFIX
+dnl Ensures $prefix and $exec_prefix are set to something sensible
+dnl
+dnl Logic taken from Geany-Plugins' build/expansions.m4
+AC_DEFUN([GEANY_PREFIX],
+[
+	if test "x$prefix" = xNONE; then
+		prefix=$ac_default_prefix
+	fi
+
+	if test "x$exec_prefix" = xNONE; then
+		exec_prefix=$prefix
+	fi
+])
+
+dnl GEANY_DOCDIR
+dnl Ensures $docdir is set and AC_SUBSTed
+dnl
+dnl FIXME: is this really useful?
+AC_DEFUN([GEANY_DOCDIR],
+[
+	if test -z "${docdir}"; then
+		docdir='${datadir}/doc/${PACKAGE}'
+		AC_SUBST([docdir])
+	fi
+])