[tracker] meson: Use relative paths for gtk-doc src_dir arguments

[Sam Thursfield <sthursfield src gnome org>]

commit c243e4ba85ca4a1246ca94c86e2dff2e40481f2f
Author: Sam Thursfield <sam afuera me uk>
Date:   Fri Apr 20 18:59:19 2018 +0200

    meson: Use relative paths for gtk-doc src_dir arguments
    
    Using absolute paths breaks if we are embedded as a subproject because
    the toplevel path is that of the toplevel project.

 docs/reference/libtracker-control/meson.build |    2 +-
 docs/reference/libtracker-miner/meson.build   |    2 +-
 docs/reference/libtracker-sparql/meson.build  |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/docs/reference/libtracker-control/meson.build b/docs/reference/libtracker-control/meson.build
index 659155d..ad067d9 100644
--- a/docs/reference/libtracker-control/meson.build
+++ b/docs/reference/libtracker-control/meson.build
@@ -3,7 +3,7 @@ version_xml = configure_file(input: 'version.xml.in',
     configuration: conf)
 
 gnome.gtkdoc('libtracker-control',
-    src_dir: 'src/libtracker-control',
+    src_dir: join_paths(meson.current_source_dir(), '..', '..', '..', 'src', 'libtracker-control'),
     main_sgml: 'libtracker-control-docs.sgml',
     content_files: ['migrating-1to2.xml'],
     install: true)
diff --git a/docs/reference/libtracker-miner/meson.build b/docs/reference/libtracker-miner/meson.build
index f3cda1a..3e92d7a 100644
--- a/docs/reference/libtracker-miner/meson.build
+++ b/docs/reference/libtracker-miner/meson.build
@@ -3,7 +3,7 @@ version_xml = configure_file(input: 'version.xml.in',
     configuration: conf)
 
 gnome.gtkdoc('libtracker-miner',
-    src_dir: 'src/libtracker-miner',
+    src_dir: join_paths(meson.current_source_dir(), '..', '..', '..', 'src', 'libtracker-miner'),
     main_sgml: 'libtracker-miner-docs.sgml',
     content_files: ['overview.sgml', 'migrating-1to2.xml'],
     install: true)
diff --git a/docs/reference/libtracker-sparql/meson.build b/docs/reference/libtracker-sparql/meson.build
index cd510bc..a6cd6e1 100644
--- a/docs/reference/libtracker-sparql/meson.build
+++ b/docs/reference/libtracker-sparql/meson.build
@@ -3,7 +3,7 @@ version_xml = configure_file(input: 'version.xml.in',
     configuration: conf)
 
 gnome.gtkdoc('libtracker-sparql',
-    src_dir: 'src/libtracker-sparql',
+    src_dir: join_paths(meson.current_source_dir(), '..', '..', '..', 'src', 'libtracker-sparql'),
     main_sgml: 'libtracker-sparql-docs.sgml',
     content_files: ['overview.sgml', 'examples.sgml', 'ontologies.sgml', 'private-store.xml', 
'migrating-1to2.xml'],
     install: true)