There is already a check that the destination object does not
exist in all other cases when processing an incoming static delta.
However, the bspatch case would still try to run and fail. Add
an analogous check to that case as well.
https://bugzilla.gnome.org/show_bug.cgi?id=756260
zlib can return LZMA_BUF_ERROR, which indicates that either
the input or output buffer has size zero. This case should cause
the correct error to be passed back from g_converter_convert
to expand the relevant buffer. Since this error is ambiguous
as to which buffer is too small, an explicit check on the
output buffer size is added as well.
https://bugzilla.gnome.org/show_bug.cgi?id=756260
Now that the computed similar objects are all regular files,
get_unpacked_unlinked_content should never be called on any other
object type. Assert that this is true instead of silently succeeding.
_ostree_delta_compute_similar_objects should not output symlinks.
Previously, a symlink in the "from" commit could be matched to a
real file in the "to" commit, since nothing was filtering symlinks
on the "from" side. This led to failures running the bzdiff
algorithm.