performance comparison

docker/test/performance-comparison/entrypoint.sh

@@ -87,7 +87,7 @@ then
     # tests for use by compare.sh. Compare to merge base, because master might be
     # far in the future and have unrelated test changes.
     base=$(git -C ch merge-base "$SHA_TO_TEST" master)
-    git -C ch diff --name-only "$SHA_TO_TEST" "$base" | tee changed-tests.txt
+    git -C ch diff --name-only "$base" "$SHA_TO_TEST" | tee changed-tests.txt
     if grep -vq '^tests/performance' changed-tests.txt
     then
         # Have some other changes besides the tests, so truncate the test list,