From a2d142e73d5abbba3f080b074b0b193a7f2ce81a Mon Sep 17 00:00:00 2001
From: Andreas Suter <andreas.suter@psi.ch>
Date: Tue, 24 Oct 2017 09:06:50 +0200
Subject: [PATCH] check if DOCDIR has not already injected from the command
 line.

---
 configure.ac | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index ceb78a7a..d421a507 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1373,11 +1373,17 @@ else
   INSTALLDIR="${prefix}"
 fi
 
-if test -d "${INSTALLDIR}/doc"
+dnl only define DOCDIR if not already present. This allows
+dnl to feed DOCDIR on the configure level which is useful when
+dnl for instance building a rpm.
+if test "x${DOCDIR}" = "x"
 then
-  DOCDIR="${INSTALLDIR}/doc/musrfit"
-else
-  DOCDIR="${INSTALLDIR}/share/doc/musrfit"
+  if test -d "${INSTALLDIR}/doc"
+  then
+    DOCDIR="${INSTALLDIR}/doc/musrfit"
+  else
+    DOCDIR="${INSTALLDIR}/share/doc/musrfit"
+  fi
 fi
 
 AC_SUBST(DOCDIR)