ci: Check that all expected piglit results are there

Without these, the build jobs would spuriously pass if some of the
expected piglit tests didn't run at all.

v2:
* Use local variables instead of starting their names with underscores
  (Peter Hutterer)

.gitlab-ci/build-and-test.sh

@@ -3,9 +3,30 @@
 set -e
 set -o xtrace
 
+check_piglit_results ()
+{
+    local EXPECTED_RESULTS=build/test/piglit-results/$1
+    local DEPENDENCY=build/$2
+
+    if ! test -e $DEPENDENCY; then
+	return
+    fi
+
+    if test -e $EXPECTED_RESULTS; then
+	return
+    fi
+
+    echo Expected $EXPECTED_RESULTS does not exist
+    exit 1
+}
+
 meson -Dc_args="-fno-common" -Dprefix=/usr -Dxephyr=true -Dwerror=true $MESON_EXTRA_OPTIONS build/
 
 ninja -j${FDO_CI_CONCURRENT:-4} -C build/ dist
 
 export PIGLIT_DIR=/root/piglit XTEST_DIR=/root/xts
 ninja -j${FDO_CI_CONCURRENT:-4} -C build/ test
+
+check_piglit_results xephyr-glamor hw/kdrive/ephyr/Xephyr.p/ephyr_glamor.c.o
+check_piglit_results xvfb hw/vfb/Xvfb
+check_piglit_results xwayland hw/xwayland/Xwayland