[librsvg] Makefile: fix VPATH (out-of-tree) builds.

[Federico Mena Quintero <federico src gnome org>]

commit 8722ae31dee6d1da047485a4763c4764bc0e06d1
Author: Jehan <jehan girinstud io>
Date:   Sat Jun 9 19:04:51 2018 +0200

    Makefile: fix VPATH (out-of-tree) builds.
    
    In `librsvg/rsvg.h`, the include is "librsvg-enum-types.h", which is a
    generated file and is therefore inside $(top_builddir)/librsvg/.

 Makefile.am                   | 6 ++++--
 gdk-pixbuf-loader/Makefile.am | 3 ++-
 tools/Makefile.am             | 1 +
 3 files changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 343bb0c6..f79f0f08 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -173,6 +173,7 @@ $(RUST_LIB): $(RUST_SRC)
 librsvg_@RSVG_API_MAJOR_VERSION@_la_CPPFLAGS = \
        -I$(top_srcdir)                         \
        -I$(top_builddir)                       \
+       -I$(top_builddir)/librsvg               \
        -DG_LOG_DOMAIN=\"librsvg\"              \
        -DLIBRSVG_DATADIR="\"$(datadir)\""      \
        -DSRCDIR=\""${abs_top_srcdir}"\"        \
@@ -215,6 +216,7 @@ rsvg_convert_SOURCES =                      \
 rsvg_convert_CPPFLAGS = \
        -I$(top_srcdir)                         \
        -I$(top_builddir)                       \
+       -I$(top_builddir)/librsvg               \
        -DLIBRSVG_DATADIR="\"$(datadir)\""      \
        $(AM_CPPFLAGS)
 
@@ -235,7 +237,7 @@ rsvg_view_3_SOURCES =                       \
 
 rsvg_view_3_CPPFLAGS = \
        -I$(top_srcdir)                         \
-       -I$(top_builddir)                       \
+       -I$(top_builddir)/librsvg               \
        -DLIBRSVG_DATADIR="\"$(datadir)\""      \
        $(AM_CPPFLAGS)
 
@@ -348,7 +350,7 @@ Rsvg_@RSVG_API_VERSION_U@_gir_PACKAGES = \
        pango \
        libxml-2.0 \
        $(NULL)
-Rsvg_@RSVG_API_VERSION_U@_gir_CFLAGS = -I$(top_builddir) -DRSVG_COMPILATION
+Rsvg_@RSVG_API_VERSION_U@_gir_CFLAGS = -I$(top_builddir) -I$(top_builddir)/librsvg -DRSVG_COMPILATION
 Rsvg_@RSVG_API_VERSION_U@_gir_LIBS = librsvg-@RSVG_API_MAJOR_VERSION@.la
 Rsvg_@RSVG_API_VERSION_U@_gir_SCANNERFLAGS = --c-include="librsvg/rsvg.h"
 
diff --git a/gdk-pixbuf-loader/Makefile.am b/gdk-pixbuf-loader/Makefile.am
index c3493736..a69eadf2 100644
--- a/gdk-pixbuf-loader/Makefile.am
+++ b/gdk-pixbuf-loader/Makefile.am
@@ -8,8 +8,9 @@ libpixbufloader_svg_la_SOURCES = \
        io-svg.c
 
 libpixbufloader_svg_la_CPPFLAGS = \
-       -I$(top_srcdir)                         \
+       -I$(top_srcdir)                         \
        -I$(top_builddir)                       \
+       -I$(top_builddir)/librsvg               \
        -DGDK_PIXBUF_ENABLE_BACKEND             \
        -DG_LOG_DOMAIN=\"libpixbufloader-svg\"  \
        $(AM_CPPFLAGS)
diff --git a/tools/Makefile.am b/tools/Makefile.am
index b3b2fc05..22a1d2c3 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -10,6 +10,7 @@ endif
 AM_CPPFLAGS =                          \
        -I$(top_srcdir)                 \
        -I$(top_builddir)               \
+       -I$(top_builddir)/librsvg       \
        $(LIBRSVG_CFLAGS)               \
        $(GTK_CFLAGS)                   \
        $(GDK_X11_CFLAGS)               \