setup: document prefix

diff --git a/xdiff-interface.c b/xdiff-interface.c
index 01f14fb50f7cf1387898a0c8db44f966ce07b720..cd2285de1cb1faa9f7c6c97dd22210f20bb046a3 100644 (file)
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -138,19 +138,20 @@ int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t co
 
 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
                  xdiff_emit_consume_fn fn, void *consume_callback_data,
-                 xpparam_t const *xpp,
-                 xdemitconf_t const *xecfg, xdemitcb_t *xecb)
+                 xpparam_t const *xpp, xdemitconf_t const *xecfg)
 {
        int ret;
        struct xdiff_emit_state state;
+       xdemitcb_t ecb;
 
        memset(&state, 0, sizeof(state));
        state.consume = fn;
        state.consume_callback_data = consume_callback_data;
-       xecb->outf = xdiff_outf;
-       xecb->priv = &state;
+       memset(&ecb, 0, sizeof(ecb));
+       ecb.outf = xdiff_outf;
+       ecb.priv = &state;
        strbuf_init(&state.remainder, 0);
-       ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
+       ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
        strbuf_release(&state.remainder);
        return ret;
 }
@@ -218,6 +219,23 @@ int read_mmfile(mmfile_t *ptr, const char *filename)
        return 0;
 }
 
+void read_mmblob(mmfile_t *ptr, const unsigned char *sha1)
+{
+       unsigned long size;
+       enum object_type type;
+
+       if (!hashcmp(sha1, null_sha1)) {
+               ptr->ptr = xstrdup("");
+               ptr->size = 0;
+               return;
+       }
+
+       ptr->ptr = read_sha1_file(sha1, &type, &size);
+       if (!ptr->ptr || type != OBJ_BLOB)
+               die("unable to read blob object %s", sha1_to_hex(sha1));
+       ptr->size = size;
+}
+
 #define FIRST_FEW_BYTES 8000
 int buffer_is_binary(const char *ptr, unsigned long size)
 {