[tracker] meson: Fix tracker-parser-sha1.h generation when we're a subproject

[Sam Thursfield <sthursfield src gnome org>]

commit 04c47c51cee373f0296e277a852c38663edc0245
Author: Sam Thursfield <sam thursfield codethink co uk>
Date:   Thu Aug 3 23:49:07 2017 +0100

    meson: Fix tracker-parser-sha1.h generation when we're a subproject
    
    I also added `-e` (fail on errors) to the script.

 .../generate-tracker-parser-sha1-header.sh         |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/libtracker-common/generate-tracker-parser-sha1-header.sh 
b/src/libtracker-common/generate-tracker-parser-sha1-header.sh
index 9d81af7..5ea9ae4 100755
--- a/src/libtracker-common/generate-tracker-parser-sha1-header.sh
+++ b/src/libtracker-common/generate-tracker-parser-sha1-header.sh
@@ -9,18 +9,18 @@
 # to. If it updates the file unconditionally, everything will rebuild from
 # scratch every time Meson reexecutes.
 
-set -u
+set -ue
 
 # Check first if we're in a git env, bail out otherwise
 git diff HEAD..HEAD >/dev/null 2>&1
 
+SRCDIR=${MESON_SOURCE_ROOT}/${MESON_SUBDIR}
+BUILDDIR=${MESON_BUILD_ROOT}/${MESON_SUBDIR}
+
 if [ $@ != 0 && -f ${BUILDDIR}/tracker-parser-sha1.h ]; then
        exit 0;
 fi
 
-SRCDIR=${MESON_SOURCE_ROOT}/src/libtracker-common
-BUILDDIR=${MESON_BUILD_ROOT}/src/libtracker-common
-
 cached_sha1=$(cat ${BUILDDIR}/tracker-parser-sha1.cached || echo "")
 new_sha1=$(git -C ${SRCDIR} log -n1 --format=format:%H -- . )