+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 DIFF_STATUS_COPIED:
+ 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 DIFF_STATUS_RENAMED:
+ 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 DIFF_STATUS_MODIFIED:
+ 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)
+{
+ int num, scale, ch, cnt;
+ const char *cp = *cp_p;
+
+ cnt = num = 0;
+ scale = 1;
+ while ('0' <= (ch = *cp) && ch <= '9') {
+ if (cnt++ < 5) {
+ /* We simply ignore more than 5 digits precision. */
+ scale *= 10;
+ num = num * 10 + ch - '0';
+ }
+ cp++;
+ }
+ *cp_p = cp;
+
+ /* user says num divided by scale and we say internally that
+ * is MAX_SCORE * num / scale.
+ */
+ return (MAX_SCORE * num / scale);
+}
+
+int diff_scoreopt_parse(const char *opt)
+{
+ int opt1, opt2, cmd;
+
+ if (*opt++ != '-')
+ return -1;
+ cmd = *opt++;
+ if (cmd != 'M' && cmd != 'C' && cmd != 'B')
+ return -1; /* that is not a -M, -C nor -B option */
+
+ opt1 = parse_num(&opt);
+ if (cmd != 'B')
+ opt2 = 0;
+ else {
+ if (*opt == 0)
+ opt2 = 0;
+ else if (*opt != '/')
+ return -1; /* we expect -B80/99 or -B80 */
+ else {
+ opt++;
+ opt2 = parse_num(&opt);
+ }
+ }
+ if (*opt != 0)
+ return -1;
+ return opt1 | (opt2 << 16);
+}
+
+struct diff_queue_struct diff_queued_diff;
+
+void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
+{
+ if (queue->alloc <= queue->nr) {
+ queue->alloc = alloc_nr(queue->alloc);
+ queue->queue = xrealloc(queue->queue,
+ sizeof(dp) * queue->alloc);
+ }
+ queue->queue[queue->nr++] = dp;
+}
+
+struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
+ struct diff_filespec *one,
+ struct diff_filespec *two)
+{
+ struct diff_filepair *dp = xmalloc(sizeof(*dp));
+ dp->one = one;
+ dp->two = two;
+ dp->score = 0;
+ dp->status = 0;
+ dp->source_stays = 0;
+ dp->broken_pair = 0;
+ diff_q(queue, dp);
+ return dp;
+}
+
+void diff_free_filepair(struct diff_filepair *p)
+{
+ diff_free_filespec(p->one);
+ diff_free_filespec(p->two);
+ free(p);
+}
+
+static void diff_flush_raw(struct diff_filepair *p,
+ int line_termination,
+ int inter_name_termination)
+{
+ int two_paths;
+ char status[10];
+
+ if (line_termination) {
+ const char *const err =
+ "path %s cannot be expressed without -z";
+ if (strchr(p->one->path, line_termination) ||
+ strchr(p->one->path, inter_name_termination))
+ die(err, p->one->path);
+ if (strchr(p->two->path, line_termination) ||
+ strchr(p->two->path, inter_name_termination))
+ die(err, p->two->path);
+ }
+
+ if (p->score)
+ sprintf(status, "%c%03d", p->status,
+ (int)(0.5 + p->score * 100.0/MAX_SCORE));
+ else {
+ status[0] = p->status;
+ status[1] = 0;
+ }
+ switch (p->status) {
+ case DIFF_STATUS_COPIED:
+ case DIFF_STATUS_RENAMED:
+ two_paths = 1;
+ break;
+ case DIFF_STATUS_ADDED:
+ case DIFF_STATUS_DELETED:
+ two_paths = 0;
+ break;
+ default:
+ two_paths = 0;
+ break;
+ }
+ printf(":%06o %06o %s ",
+ p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
+ printf("%s %s%c%s",
+ sha1_to_hex(p->two->sha1),
+ status,
+ inter_name_termination,
+ p->one->path);
+ if (two_paths)
+ printf("%c%s", inter_name_termination, p->two->path);
+ putchar(line_termination);
+}
+
+static void diff_flush_name(struct diff_filepair *p,
+ int line_termination)
+{
+ printf("%s%c", p->two->path, line_termination);
+}
+
+int diff_unmodified_pair(struct diff_filepair *p)
+{
+ /* This function is written stricter than necessary to support
+ * the currently implemented transformers, but the idea is to
+ * let transformers to produce diff_filepairs any way they want,
+ * and filter and clean them up here before producing the output.
+ */
+ struct diff_filespec *one, *two;
+
+ if (DIFF_PAIR_UNMERGED(p))
+ return 0; /* unmerged is interesting */
+
+ one = p->one;
+ two = p->two;
+
+ /* deletion, addition, mode or type change
+ * and rename are all interesting.
+ */
+ if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
+ DIFF_PAIR_MODE_CHANGED(p) ||
+ strcmp(one->path, two->path))
+ return 0;
+
+ /* both are valid and point at the same path. that is, we are
+ * dealing with a change.
+ */
+ if (one->sha1_valid && two->sha1_valid &&
+ !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
+ return 1; /* no change */
+ if (!one->sha1_valid && !two->sha1_valid)
+ return 1; /* both look at the same file on the filesystem. */
+ return 0;
+}
+
+static void diff_flush_patch(struct diff_filepair *p)
+{
+ if (diff_unmodified_pair(p))
+ return;
+
+ if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
+ (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
+ return; /* no tree diffs in patch format */
+
+ run_diff(p);
+}
+
+int diff_queue_is_empty(void)