docs: do xrefs for non installed books too

Get the xrefs from the builddir for the books in the same package. This fixes
the cross references if one does not have the docs already installed.

diff --git a/docs/plugins/Makefile.am b/docs/plugins/Makefile.am
index 9beea7e..c987b85 100644 (file)
--- a/docs/plugins/Makefile.am
+++ b/docs/plugins/Makefile.am
@@ -48,7 +48,8 @@ SCAN_OPTIONS=
 MKDB_OPTIONS=--sgml-mode
 
 # Extra options to supply to gtkdoc-fixref.
-FIXXREF_OPTIONS=--extra-dir=$(GLIB_PREFIX)/share/gtk-doc/html \
+FIXXREF_OPTIONS=--extra-dir=$(top_builddir)/docs/libs/html \
+       --extra-dir=$(GLIB_PREFIX)/share/gtk-doc/html \
        --extra-dir=$(GST_PREFIX)/share/gtk-doc/html \
        --extra-dir=$(datadir)/gtk-doc/html