+static int similarity_index(struct diff_filepair *p)
+{
+ return p->score * 100 / MAX_SCORE;
+}
+
+static void fill_metainfo(struct strbuf *msg,
+ const char *name,
+ const char *other,
+ struct diff_filespec *one,
+ struct diff_filespec *two,
+ struct diff_options *o,
+ struct diff_filepair *p)
+{
+ strbuf_init(msg, PATH_MAX * 2 + 300);
+ switch (p->status) {
+ case DIFF_STATUS_COPIED:
+ strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
+ strbuf_addstr(msg, "\ncopy from ");
+ quote_c_style(name, msg, NULL, 0);
+ strbuf_addstr(msg, "\ncopy to ");
+ quote_c_style(other, msg, NULL, 0);
+ strbuf_addch(msg, '\n');
+ break;
+ case DIFF_STATUS_RENAMED:
+ strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
+ strbuf_addstr(msg, "\nrename from ");
+ quote_c_style(name, msg, NULL, 0);
+ strbuf_addstr(msg, "\nrename to ");
+ quote_c_style(other, msg, NULL, 0);
+ strbuf_addch(msg, '\n');
+ break;
+ case DIFF_STATUS_MODIFIED:
+ if (p->score) {
+ strbuf_addf(msg, "dissimilarity index %d%%\n",
+ similarity_index(p));
+ break;
+ }
+ /* fallthru */
+ default:
+ /* nothing */
+ ;
+ }
+ if (one && two && hashcmp(one->sha1, two->sha1)) {
+ int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
+
+ if (DIFF_OPT_TST(o, BINARY)) {
+ mmfile_t mf;
+ if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
+ (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
+ abbrev = 40;
+ }
+ strbuf_addf(msg, "index %.*s..%.*s",
+ abbrev, sha1_to_hex(one->sha1),
+ abbrev, sha1_to_hex(two->sha1));
+ if (one->mode == two->mode)
+ strbuf_addf(msg, " %06o", one->mode);
+ strbuf_addch(msg, '\n');
+ }
+ if (msg->len)
+ strbuf_setlen(msg, msg->len - 1);
+}
+