add -e: do not show difference in a submodule that is merely dirty

[git.git] / builtin / pack-objects.c

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c6e2d8766b0ec15fcfe9dc0a60ee81db6750b527..8bfe3a6ffb11fb2fc0956043dfafc2f3f66adccf 100644 (file)
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1248,11 +1248,16 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
                return -1;
 
        /*
-        * We do not bother to try a delta that we discarded
-        * on an earlier try, but only when reusing delta data.
+        * We do not bother to try a delta that we discarded on an
+        * earlier try, but only when reusing delta data.  Note that
+        * src_entry that is marked as the preferred_base should always
+        * be considered, as even if we produce a suboptimal delta against
+        * it, we will still save the transfer cost, as we already know
+        * the other side has it and we won't send src_entry at all.
         */
        if (reuse_delta && trg_entry->in_pack &&
            trg_entry->in_pack == src_entry->in_pack &&
+           !src_entry->preferred_base &&
            trg_entry->in_pack_type != OBJ_REF_DELTA &&
            trg_entry->in_pack_type != OBJ_OFS_DELTA)
                return 0;