merge-file: enforce MAX_XDIFF_SIZE on incoming files

The previous commit enforces MAX_XDIFF_SIZE at the
interfaces to xdiff: xdi_diff (which calls xdl_diff) and
ll_xdl_merge (which calls xdl_merge).

But we have another direct call to xdl_merge in
merge-file.c. If it were written today, this probably would
just use the ll_merge machinery. But it predates that code,
and uses slightly different options to xdl_merge (e.g.,
ZEALOUS_ALNUM).

We could try to abstract out an xdi_merge to match the
existing xdi_diff, but even that is difficult. Rather than
simply report error, we try to treat large files as binary,
and that distinction would happen outside of xdi_merge.

The simplest fix is to just replicate the MAX_XDIFF_SIZE
check in merge-file.c.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/merge-file.c b/builtin/merge-file.c
index 232b768..04ae36a 100644 (file)
--- a/builtin/merge-file.c
+++ b/builtin/merge-file.c
@@ -75,7 +75,8 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
                        names[i] = argv[i];
                if (read_mmfile(mmfs + i, fname))
                        return -1;
-               if (buffer_is_binary(mmfs[i].ptr, mmfs[i].size))
+               if (mmfs[i].size > MAX_XDIFF_SIZE ||
+                   buffer_is_binary(mmfs[i].ptr, mmfs[i].size))
                        return error("Cannot merge binary files: %s",
                                        argv[i]);
        }