[gom] python: Fix distcheck

[Bastien Nocera <hadess src gnome org>]

commit bd947a06e2346cf561aae9874b27ee15e585f4fa
Author: Bastien Nocera <hadess hadess net>
Date:   Sat Dec 26 18:25:21 2015 +0100

    python: Fix distcheck
    
    Installation failed during distcheck as it tried to install in the
    system Python directories, which normal users can't install to.

 Makefile.am  |    6 +++++-
 configure.ac |   16 ++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index e793b0b..8ce24d3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -8,7 +8,11 @@ include tests/Makefile.include
 SUBDIRS = . doc po
 
 ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
-DISTCHECK_CONFIGURE_FLAGS = --enable-gtk-doc --enable-introspection --enable-silent-rules
+DISTCHECK_CONFIGURE_FLAGS =                    \
+       --enable-gtk-doc                        \
+       --enable-introspection                  \
+       --enable-silent-rules                   \
+       --with-pythondir='$${libdir}/python-gom-distcheck/site-packages/gi/overrides'
 
 EXTRA_DIST += README COPYING NEWS
 
diff --git a/configure.ac b/configure.ac
index 5a3f84c..6373a8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -163,14 +163,26 @@ else
     else
         PKG_CHECK_MODULES(pygobject, [pygobject-3.0 >= 3.16.0], [
             found_python="yes"
-            pyoverridesdir=`$PYTHON -c "import gi; print(gi._overridesdir)"`
-            AC_SUBST(pyoverridesdir)
         ], [
             found_python="no"
         ])
     fi
 fi
 
+AC_ARG_WITH(pythondir,
+           AS_HELP_STRING([--with-pythondir=DIR],[Installation path for Python bindings @<:@auto@:>@]),
+           [ac_with_pythondir=$withval],
+           [ac_with_pythondir=""])
+
+if test "x$found_python" = "xyes"; then
+    if test "x$ac_with_pythondir" = "x"; then
+        pyoverridesdir=`$PYTHON -c "import gi; print(gi._overridesdir)"`
+        AC_SUBST(pyoverridesdir)
+    else
+        pyoverridesdir="$ac_with_pythondir"
+    fi
+fi
+
 if test "x$enable_python" = "xyes" -a "x$found_python" != "xyes"; then
     AC_MSG_ERROR([You need to have Python 3 and PyGObject installed])
 fi