+static void run_external_diff(const char *pgm,
+ const char *name,
+ const char *other,
+ struct diff_filespec *one,
+ struct diff_filespec *two,
+ const char *xfrm_msg,
+ int complete_rewrite)
+{
+ struct diff_tempfile *temp = diff_temp;
+ pid_t pid;
+ int status;
+ static int atexit_asked = 0;
+
+ if (one && two) {
+ prepare_temp_file(name, &temp[0], one);
+ prepare_temp_file(other ? : name, &temp[1], two);
+ if (! atexit_asked &&
+ (temp[0].name == temp[0].tmp_path ||
+ temp[1].name == temp[1].tmp_path)) {
+ atexit_asked = 1;
+ atexit(remove_tempfile);
+ }
+ signal(SIGINT, remove_tempfile_on_signal);
+ }
+
+ fflush(NULL);
+ pid = fork();
+ if (pid < 0)
+ die("unable to fork");
+ if (!pid) {
+ if (pgm) {
+ if (one && two) {
+ const char *exec_arg[10];
+ const char **arg = &exec_arg[0];
+ *arg++ = pgm;
+ *arg++ = name;
+ *arg++ = temp[0].name;
+ *arg++ = temp[0].hex;
+ *arg++ = temp[0].mode;
+ *arg++ = temp[1].name;
+ *arg++ = temp[1].hex;
+ *arg++ = temp[1].mode;
+ if (other) {
+ *arg++ = other;
+ *arg++ = xfrm_msg;
+ }
+ *arg = NULL;
+ execvp(pgm, (char *const*) exec_arg);
+ }
+ else
+ execlp(pgm, pgm, name, NULL);
+ }
+ /*
+ * otherwise we use the built-in one.
+ */
+ if (one && two)
+ builtin_diff(name, other ? : name, temp, xfrm_msg,
+ complete_rewrite);
+ else
+ printf("* Unmerged path %s\n", name);
+ exit(0);
+ }
+ if (waitpid(pid, &status, 0) < 0 ||
+ !WIFEXITED(status) || WEXITSTATUS(status)) {
+ /* Earlier we did not check the exit status because
+ * diff exits non-zero if files are different, and
+ * we are not interested in knowing that. It was a
+ * mistake which made it harder to quit a diff-*
+ * session that uses the git-apply-patch-script as
+ * the GIT_EXTERNAL_DIFF. A custom GIT_EXTERNAL_DIFF
+ * should also exit non-zero only when it wants to
+ * abort the entire diff-* session.
+ */
+ remove_tempfile();
+ fprintf(stderr, "external diff died, stopping at %s.\n", name);
+ exit(1);
+ }
+ remove_tempfile();
+}
+
+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)
+{
+ 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_data(p->one);
+ diff_free_filespec_data(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 *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 'C': case 'R':
+ two_paths = 1;
+ break;
+ case 'N': case 'D':
+ 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)
+{
+ struct diff_queue_struct *q = &diff_queued_diff;
+ int i;
+ for (i = 0; i < q->nr; i++)
+ if (!diff_unmodified_pair(q->queue[i]))
+ return 0;
+ return 1;
+}
+
+#if DIFF_DEBUG
+void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
+{
+ fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
+ x, one ? : "",
+ s->path,
+ DIFF_FILE_VALID(s) ? "valid" : "invalid",
+ s->mode,
+ s->sha1_valid ? sha1_to_hex(s->sha1) : "");
+ fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
+ x, one ? : "",
+ s->size, s->xfrm_flags);
+}
+
+void diff_debug_filepair(const struct diff_filepair *p, int i)
+{
+ diff_debug_filespec(p->one, i, "one");
+ diff_debug_filespec(p->two, i, "two");
+ fprintf(stderr, "score %d, status %c stays %d broken %d\n",
+ p->score, p->status ? : '?',
+ p->source_stays, p->broken_pair);
+}
+
+void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
+{
+ int i;
+ if (msg)
+ fprintf(stderr, "%s\n", msg);
+ fprintf(stderr, "q->nr = %d\n", q->nr);
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ diff_debug_filepair(p, i);
+ }
+}
+#endif
+
+static void diff_resolve_rename_copy(void)
+{
+ int i, j;
+ struct diff_filepair *p, *pp;
+ struct diff_queue_struct *q = &diff_queued_diff;
+
+ diff_debug_queue("resolve-rename-copy", q);
+
+ for (i = 0; i < q->nr; i++) {
+ p = q->queue[i];
+ p->status = 0; /* undecided */
+ if (DIFF_PAIR_UNMERGED(p))
+ p->status = 'U';
+ else if (!DIFF_FILE_VALID(p->one))
+ p->status = 'N';
+ else if (!DIFF_FILE_VALID(p->two))
+ p->status = 'D';
+ else if (DIFF_PAIR_TYPE_CHANGED(p))
+ p->status = 'T';
+
+ /* from this point on, we are dealing with a pair
+ * whose both sides are valid and of the same type, i.e.
+ * either in-place edit or rename/copy edit.
+ */
+ else if (DIFF_PAIR_RENAME(p)) {
+ if (p->source_stays) {
+ p->status = 'C';
+ continue;
+ }
+ /* See if there is some other filepair that
+ * copies from the same source as us. If so
+ * we are a copy. Otherwise we are a rename.
+ */
+ for (j = i + 1; j < q->nr; j++) {
+ pp = q->queue[j];
+ if (strcmp(pp->one->path, p->one->path))
+ continue; /* not us */
+ if (!DIFF_PAIR_RENAME(pp))
+ continue; /* not a rename/copy */
+ /* pp is a rename/copy from the same source */
+ p->status = 'C';
+ break;
+ }
+ if (!p->status)
+ p->status = 'R';
+ }
+ else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
+ p->one->mode != p->two->mode)
+ p->status = 'M';