Letting "foo" denote "wuffs_base__note__i_o_redirect", it wasn't really that "foo was unused", it was that "foo was unused, after the previous (artificial) commit renamed all-but-one of the foo references to another existing string constant". That previous commit set it up so that this commit, which exhibits the performance difference, has a trivially small diff. But the two commits combined to remove a "foo" that was actually in use, so the combination was rolled back.
Letting "foo" denote "wuffs_base__note__i_o_redirect", it wasn't really that "foo was unused", it was that "foo was unused, after the previous (artificial) commit renamed all-but-one of the foo references to another existing string constant". That previous commit set it up so that this commit, which exhibits the performance difference, has a trivially small diff. But the two commits combined to remove a "foo" that was actually in use, so the combination was rolled back.
The previous commit is https://github.com/google/wuffs/commit/844fc9b5eeef46edab49c...