+static void run_diff(struct diff_filepair *p)
+{
+ const char *pgm = external_diff();
+ char msg_[PATH_MAX*2+200], *xfrm_msg;
+ struct diff_filespec *one;
+ struct diff_filespec *two;
+ const char *name;
+ const char *other;
+ int complete_rewrite = 0;
+
+ if (DIFF_PAIR_UNMERGED(p)) {
+ /* unmerged */
+ run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
+ 0);
+ return;
+ }
+
+ name = p->one->path;
+ other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+ one = p->one; two = p->two;
+ switch (p->status) {
+ case 'C':
+ sprintf(msg_,
+ "similarity index %d%%\n"
+ "copy from %s\n"
+ "copy to %s",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE),
+ name, other);
+ xfrm_msg = msg_;
+ break;
+ case 'R':
+ sprintf(msg_,
+ "similarity index %d%%\n"
+ "rename from %s\n"
+ "rename to %s",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE),
+ name, other);
+ xfrm_msg = msg_;
+ break;
+ case 'M':
+ if (p->score) {
+ sprintf(msg_,
+ "dissimilarity index %d%%",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE));
+ xfrm_msg = msg_;
+ complete_rewrite = 1;
+ break;
+ }
+ /* fallthru */
+ default:
+ xfrm_msg = NULL;
+ }
+
+ if (!pgm &&
+ DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
+ (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
+ /* a filepair that changes between file and symlink
+ * needs to be split into deletion and creation.
+ */
+ struct diff_filespec *null = alloc_filespec(two->path);
+ run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
+ free(null);
+ null = alloc_filespec(one->path);
+ run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
+ free(null);
+ }
+ else
+ run_external_diff(pgm, name, other, one, two, xfrm_msg,
+ complete_rewrite);
+}
+
+void diff_setup(int flags)
+{
+ if (flags & DIFF_SETUP_REVERSE)
+ reverse_diff = 1;
+ if (flags & DIFF_SETUP_USE_CACHE) {
+ if (!active_cache)
+ /* read-cache does not die even when it fails
+ * so it is safe for us to do this here. Also
+ * it does not smudge active_cache or active_nr
+ * when it fails, so we do not have to worry about
+ * cleaning it up oufselves either.
+ */
+ read_cache();
+ }
+ if (flags & DIFF_SETUP_USE_SIZE_CACHE)
+ use_size_cache = 1;
+
+}
+
+static int parse_num(const char **cp_p)