add-patch.c

   1 #include "cache.h"
   2 #include "add-interactive.h"
   3 #include "strbuf.h"
   4 #include "run-command.h"
   5 #include "argv-array.h"
   6 #include "pathspec.h"
   7 #include "color.h"
   8 #include "diff.h"
   9 #include "compat/terminal.h"
  10 #include "prompt.h"
  11
  12 enum prompt_mode_type {
  13         PROMPT_MODE_CHANGE = 0, PROMPT_DELETION, PROMPT_ADDITION, PROMPT_HUNK,
  14         PROMPT_MODE_MAX, /* must be last */
  15 };
  16
  17 struct patch_mode {
  18         /*
  19          * The magic constant 4 is chosen such that all patch modes
  20          * provide enough space for three command-line arguments followed by a
  21          * trailing `NULL`.
  22          */
  23         const char *diff_cmd[4], *apply_args[4], *apply_check_args[4];
  24         unsigned is_reverse:1, index_only:1, apply_for_checkout:1;
  25         const char *prompt_mode[PROMPT_MODE_MAX];
  26         const char *edit_hunk_hint, *help_patch_text;
  27 };
  28
  29 static struct patch_mode patch_mode_add = {
  30         .diff_cmd = { "diff-files", NULL },
  31         .apply_args = { "--cached", NULL },
  32         .apply_check_args = { "--cached", NULL },
  33         .prompt_mode = {
  34                 N_("Stage mode change [y,n,q,a,d%s,?]? "),
  35                 N_("Stage deletion [y,n,q,a,d%s,?]? "),
  36                 N_("Stage addition [y,n,q,a,d%s,?]? "),
  37                 N_("Stage this hunk [y,n,q,a,d%s,?]? ")
  38         },
  39         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
  40                              "will immediately be marked for staging."),
  41         .help_patch_text =
  42                 N_("y - stage this hunk\n"
  43                    "n - do not stage this hunk\n"
  44                    "q - quit; do not stage this hunk or any of the remaining "
  45                         "ones\n"
  46                    "a - stage this hunk and all later hunks in the file\n"
  47                    "d - do not stage this hunk or any of the later hunks in "
  48                         "the file\n")
  49 };
  50
  51 static struct patch_mode patch_mode_stash = {
  52         .diff_cmd = { "diff-index", "HEAD", NULL },
  53         .apply_args = { "--cached", NULL },
  54         .apply_check_args = { "--cached", NULL },
  55         .prompt_mode = {
  56                 N_("Stash mode change [y,n,q,a,d%s,?]? "),
  57                 N_("Stash deletion [y,n,q,a,d%s,?]? "),
  58                 N_("Stash addition [y,n,q,a,d%s,?]? "),
  59                 N_("Stash this hunk [y,n,q,a,d%s,?]? "),
  60         },
  61         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
  62                              "will immediately be marked for stashing."),
  63         .help_patch_text =
  64                 N_("y - stash this hunk\n"
  65                    "n - do not stash this hunk\n"
  66                    "q - quit; do not stash this hunk or any of the remaining "
  67                         "ones\n"
  68                    "a - stash this hunk and all later hunks in the file\n"
  69                    "d - do not stash this hunk or any of the later hunks in "
  70                         "the file\n"),
  71 };
  72
  73 static struct patch_mode patch_mode_reset_head = {
  74         .diff_cmd = { "diff-index", "--cached", NULL },
  75         .apply_args = { "-R", "--cached", NULL },
  76         .apply_check_args = { "-R", "--cached", NULL },
  77         .is_reverse = 1,
  78         .index_only = 1,
  79         .prompt_mode = {
  80                 N_("Unstage mode change [y,n,q,a,d%s,?]? "),
  81                 N_("Unstage deletion [y,n,q,a,d%s,?]? "),
  82                 N_("Unstage addition [y,n,q,a,d%s,?]? "),
  83                 N_("Unstage this hunk [y,n,q,a,d%s,?]? "),
  84         },
  85         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
  86                              "will immediately be marked for unstaging."),
  87         .help_patch_text =
  88                 N_("y - unstage this hunk\n"
  89                    "n - do not unstage this hunk\n"
  90                    "q - quit; do not unstage this hunk or any of the remaining "
  91                         "ones\n"
  92                    "a - unstage this hunk and all later hunks in the file\n"
  93                    "d - do not unstage this hunk or any of the later hunks in "
  94                         "the file\n"),
  95 };
  96
  97 static struct patch_mode patch_mode_reset_nothead = {
  98         .diff_cmd = { "diff-index", "-R", "--cached", NULL },
  99         .apply_args = { "--cached", NULL },
 100         .apply_check_args = { "--cached", NULL },
 101         .index_only = 1,
 102         .prompt_mode = {
 103                 N_("Apply mode change to index [y,n,q,a,d%s,?]? "),
 104                 N_("Apply deletion to index [y,n,q,a,d%s,?]? "),
 105                 N_("Apply addition to index [y,n,q,a,d%s,?]? "),
 106                 N_("Apply this hunk to index [y,n,q,a,d%s,?]? "),
 107         },
 108         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
 109                              "will immediately be marked for applying."),
 110         .help_patch_text =
 111                 N_("y - apply this hunk to index\n"
 112                    "n - do not apply this hunk to index\n"
 113                    "q - quit; do not apply this hunk or any of the remaining "
 114                         "ones\n"
 115                    "a - apply this hunk and all later hunks in the file\n"
 116                    "d - do not apply this hunk or any of the later hunks in "
 117                         "the file\n"),
 118 };
 119
 120 static struct patch_mode patch_mode_checkout_index = {
 121         .diff_cmd = { "diff-files", NULL },
 122         .apply_args = { "-R", NULL },
 123         .apply_check_args = { "-R", NULL },
 124         .is_reverse = 1,
 125         .prompt_mode = {
 126                 N_("Discard mode change from worktree [y,n,q,a,d%s,?]? "),
 127                 N_("Discard deletion from worktree [y,n,q,a,d%s,?]? "),
 128                 N_("Discard addition from worktree [y,n,q,a,d%s,?]? "),
 129                 N_("Discard this hunk from worktree [y,n,q,a,d%s,?]? "),
 130         },
 131         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
 132                              "will immediately be marked for discarding."),
 133         .help_patch_text =
 134                 N_("y - discard this hunk from worktree\n"
 135                    "n - do not discard this hunk from worktree\n"
 136                    "q - quit; do not discard this hunk or any of the remaining "
 137                         "ones\n"
 138                    "a - discard this hunk and all later hunks in the file\n"
 139                    "d - do not discard this hunk or any of the later hunks in "
 140                         "the file\n"),
 141 };
 142
 143 static struct patch_mode patch_mode_checkout_head = {
 144         .diff_cmd = { "diff-index", NULL },
 145         .apply_for_checkout = 1,
 146         .apply_check_args = { "-R", NULL },
 147         .is_reverse = 1,
 148         .prompt_mode = {
 149                 N_("Discard mode change from index and worktree [y,n,q,a,d%s,?]? "),
 150                 N_("Discard deletion from index and worktree [y,n,q,a,d%s,?]? "),
 151                 N_("Discard addition from index and worktree [y,n,q,a,d%s,?]? "),
 152                 N_("Discard this hunk from index and worktree [y,n,q,a,d%s,?]? "),
 153         },
 154         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
 155                              "will immediately be marked for discarding."),
 156         .help_patch_text =
 157                 N_("y - discard this hunk from index and worktree\n"
 158                    "n - do not discard this hunk from index and worktree\n"
 159                    "q - quit; do not discard this hunk or any of the remaining "
 160                         "ones\n"
 161                    "a - discard this hunk and all later hunks in the file\n"
 162                    "d - do not discard this hunk or any of the later hunks in "
 163                         "the file\n"),
 164 };
 165
 166 static struct patch_mode patch_mode_checkout_nothead = {
 167         .diff_cmd = { "diff-index", "-R", NULL },
 168         .apply_for_checkout = 1,
 169         .apply_check_args = { NULL },
 170         .prompt_mode = {
 171                 N_("Apply mode change to index and worktree [y,n,q,a,d%s,?]? "),
 172                 N_("Apply deletion to index and worktree [y,n,q,a,d%s,?]? "),
 173                 N_("Apply addition to index and worktree [y,n,q,a,d%s,?]? "),
 174                 N_("Apply this hunk to index and worktree [y,n,q,a,d%s,?]? "),
 175         },
 176         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
 177                              "will immediately be marked for applying."),
 178         .help_patch_text =
 179                 N_("y - apply this hunk to index and worktree\n"
 180                    "n - do not apply this hunk to index and worktree\n"
 181                    "q - quit; do not apply this hunk or any of the remaining "
 182                         "ones\n"
 183                    "a - apply this hunk and all later hunks in the file\n"
 184                    "d - do not apply this hunk or any of the later hunks in "
 185                         "the file\n"),
 186 };
 187
 188 static struct patch_mode patch_mode_worktree_head = {
 189         .diff_cmd = { "diff-index", NULL },
 190         .apply_args = { "-R", NULL },
 191         .apply_check_args = { "-R", NULL },
 192         .is_reverse = 1,
 193         .prompt_mode = {
 194                 N_("Discard mode change from index and worktree [y,n,q,a,d%s,?]? "),
 195                 N_("Discard deletion from index and worktree [y,n,q,a,d%s,?]? "),
 196                 N_("Discard addition from index and worktree [y,n,q,a,d%s,?]? "),
 197                 N_("Discard this hunk from index and worktree [y,n,q,a,d%s,?]? "),
 198         },
 199         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
 200                              "will immediately be marked for discarding."),
 201         .help_patch_text =
 202                 N_("y - discard this hunk from worktree\n"
 203                    "n - do not discard this hunk from worktree\n"
 204                    "q - quit; do not discard this hunk or any of the remaining "
 205                         "ones\n"
 206                    "a - discard this hunk and all later hunks in the file\n"
 207                    "d - do not discard this hunk or any of the later hunks in "
 208                         "the file\n"),
 209 };
 210
 211 static struct patch_mode patch_mode_worktree_nothead = {
 212         .diff_cmd = { "diff-index", "-R", NULL },
 213         .apply_args = { NULL },
 214         .apply_check_args = { NULL },
 215         .prompt_mode = {
 216                 N_("Apply mode change to index and worktree [y,n,q,a,d%s,?]? "),
 217                 N_("Apply deletion to index and worktree [y,n,q,a,d%s,?]? "),
 218                 N_("Apply addition to index and worktree [y,n,q,a,d%s,?]? "),
 219                 N_("Apply this hunk to index and worktree [y,n,q,a,d%s,?]? "),
 220         },
 221         .edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
 222                              "will immediately be marked for applying."),
 223         .help_patch_text =
 224                 N_("y - apply this hunk to worktree\n"
 225                    "n - do not apply this hunk to worktree\n"
 226                    "q - quit; do not apply this hunk or any of the remaining "
 227                         "ones\n"
 228                    "a - apply this hunk and all later hunks in the file\n"
 229                    "d - do not apply this hunk or any of the later hunks in "
 230                         "the file\n"),
 231 };
 232
 233 struct hunk_header {
 234         unsigned long old_offset, old_count, new_offset, new_count;
 235         /*
 236          * Start/end offsets to the extra text after the second `@@` in the
 237          * hunk header, e.g. the function signature. This is expected to
 238          * include the newline.
 239          */
 240         size_t extra_start, extra_end, colored_extra_start, colored_extra_end;
 241 };
 242
 243 struct hunk {
 244         size_t start, end, colored_start, colored_end, splittable_into;
 245         ssize_t delta;
 246         enum { UNDECIDED_HUNK = 0, SKIP_HUNK, USE_HUNK } use;
 247         struct hunk_header header;
 248 };
 249
 250 struct add_p_state {
 251         struct add_i_state s;
 252         struct strbuf answer, buf;
 253
 254         /* parsed diff */
 255         struct strbuf plain, colored;
 256         struct file_diff {
 257                 struct hunk head;
 258                 struct hunk *hunk;
 259                 size_t hunk_nr, hunk_alloc;
 260                 unsigned deleted:1, added:1, mode_change:1,binary:1;
 261         } *file_diff;
 262         size_t file_diff_nr;
 263
 264         /* patch mode */
 265         struct patch_mode *mode;
 266         const char *revision;
 267 };
 268
 269 static void err(struct add_p_state *s, const char *fmt, ...)
 270 {
 271         va_list args;
 272
 273         va_start(args, fmt);
 274         fputs(s->s.error_color, stderr);
 275         vfprintf(stderr, fmt, args);
 276         fputs(s->s.reset_color, stderr);
 277         fputc('\n', stderr);
 278         va_end(args);
 279 }
 280
 281 static void setup_child_process(struct add_p_state *s,
 282                                 struct child_process *cp, ...)
 283 {
 284         va_list ap;
 285         const char *arg;
 286
 287         va_start(ap, cp);
 288         while ((arg = va_arg(ap, const char *)))
 289                 argv_array_push(&cp->args, arg);
 290         va_end(ap);
 291
 292         cp->git_cmd = 1;
 293         argv_array_pushf(&cp->env_array,
 294                          INDEX_ENVIRONMENT "=%s", s->s.r->index_file);
 295 }
 296
 297 static int parse_range(const char **p,
 298                        unsigned long *offset, unsigned long *count)
 299 {
 300         char *pend;
 301
 302         *offset = strtoul(*p, &pend, 10);
 303         if (pend == *p)
 304                 return -1;
 305         if (*pend != ',') {
 306                 *count = 1;
 307                 *p = pend;
 308                 return 0;
 309         }
 310         *count = strtoul(pend + 1, (char **)p, 10);
 311         return *p == pend + 1 ? -1 : 0;
 312 }
 313
 314 static int parse_hunk_header(struct add_p_state *s, struct hunk *hunk)
 315 {
 316         struct hunk_header *header = &hunk->header;
 317         const char *line = s->plain.buf + hunk->start, *p = line;
 318         char *eol = memchr(p, '\n', s->plain.len - hunk->start);
 319
 320         if (!eol)
 321                 eol = s->plain.buf + s->plain.len;
 322
 323         if (!skip_prefix(p, "@@ -", &p) ||
 324             parse_range(&p, &header->old_offset, &header->old_count) < 0 ||
 325             !skip_prefix(p, " +", &p) ||
 326             parse_range(&p, &header->new_offset, &header->new_count) < 0 ||
 327             !skip_prefix(p, " @@", &p))
 328                 return error(_("could not parse hunk header '%.*s'"),
 329                              (int)(eol - line), line);
 330
 331         hunk->start = eol - s->plain.buf + (*eol == '\n');
 332         header->extra_start = p - s->plain.buf;
 333         header->extra_end = hunk->start;
 334
 335         if (!s->colored.len) {
 336                 header->colored_extra_start = header->colored_extra_end = 0;
 337                 return 0;
 338         }
 339
 340         /* Now find the extra text in the colored diff */
 341         line = s->colored.buf + hunk->colored_start;
 342         eol = memchr(line, '\n', s->colored.len - hunk->colored_start);
 343         if (!eol)
 344                 eol = s->colored.buf + s->colored.len;
 345         p = memmem(line, eol - line, "@@ -", 4);
 346         if (!p)
 347                 return error(_("could not parse colored hunk header '%.*s'"),
 348                              (int)(eol - line), line);
 349         p = memmem(p + 4, eol - p - 4, " @@", 3);
 350         if (!p)
 351                 return error(_("could not parse colored hunk header '%.*s'"),
 352                              (int)(eol - line), line);
 353         hunk->colored_start = eol - s->colored.buf + (*eol == '\n');
 354         header->colored_extra_start = p + 3 - s->colored.buf;
 355         header->colored_extra_end = hunk->colored_start;
 356
 357         return 0;
 358 }
 359
 360 static int is_octal(const char *p, size_t len)
 361 {
 362         if (!len)
 363                 return 0;
 364
 365         while (len--)
 366                 if (*p < '0' || *(p++) > '7')
 367                         return 0;
 368         return 1;
 369 }
 370
 371 static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 372 {
 373         struct argv_array args = ARGV_ARRAY_INIT;
 374         const char *diff_algorithm = s->s.interactive_diff_algorithm;
 375         struct strbuf *plain = &s->plain, *colored = NULL;
 376         struct child_process cp = CHILD_PROCESS_INIT;
 377         char *p, *pend, *colored_p = NULL, *colored_pend = NULL, marker = '\0';
 378         size_t file_diff_alloc = 0, i, color_arg_index;
 379         struct file_diff *file_diff = NULL;
 380         struct hunk *hunk = NULL;
 381         int res;
 382
 383         argv_array_pushv(&args, s->mode->diff_cmd);
 384         if (diff_algorithm)
 385                 argv_array_pushf(&args, "--diff-algorithm=%s", diff_algorithm);
 386         if (s->revision) {
 387                 struct object_id oid;
 388                 argv_array_push(&args,
 389                                 /* could be on an unborn branch */
 390                                 !strcmp("HEAD", s->revision) &&
 391                                 get_oid("HEAD", &oid) ?
 392                                 empty_tree_oid_hex() : s->revision);
 393         }
 394         color_arg_index = args.argc;
 395         /* Use `--no-color` explicitly, just in case `diff.color = always`. */
 396         argv_array_pushl(&args, "--no-color", "-p", "--", NULL);
 397         for (i = 0; i < ps->nr; i++)
 398                 argv_array_push(&args, ps->items[i].original);
 399
 400         setup_child_process(s, &cp, NULL);
 401         cp.argv = args.argv;
 402         res = capture_command(&cp, plain, 0);
 403         if (res) {
 404                 argv_array_clear(&args);
 405                 return error(_("could not parse diff"));
 406         }
 407         if (!plain->len) {
 408                 argv_array_clear(&args);
 409                 return 0;
 410         }
 411         strbuf_complete_line(plain);
 412
 413         if (want_color_fd(1, -1)) {
 414                 struct child_process colored_cp = CHILD_PROCESS_INIT;
 415                 const char *diff_filter = s->s.interactive_diff_filter;
 416
 417                 setup_child_process(s, &colored_cp, NULL);
 418                 xsnprintf((char *)args.argv[color_arg_index], 8, "--color");
 419                 colored_cp.argv = args.argv;
 420                 colored = &s->colored;
 421                 res = capture_command(&colored_cp, colored, 0);
 422                 argv_array_clear(&args);
 423                 if (res)
 424                         return error(_("could not parse colored diff"));
 425
 426                 if (diff_filter) {
 427                         struct child_process filter_cp = CHILD_PROCESS_INIT;
 428
 429                         setup_child_process(s, &filter_cp,
 430                                             diff_filter, NULL);
 431                         filter_cp.git_cmd = 0;
 432                         filter_cp.use_shell = 1;
 433                         strbuf_reset(&s->buf);
 434                         if (pipe_command(&filter_cp,
 435                                          colored->buf, colored->len,
 436                                          &s->buf, colored->len,
 437                                          NULL, 0) < 0)
 438                                 return error(_("failed to run '%s'"),
 439                                              diff_filter);
 440                         strbuf_swap(colored, &s->buf);
 441                 }
 442
 443                 strbuf_complete_line(colored);
 444                 colored_p = colored->buf;
 445                 colored_pend = colored_p + colored->len;
 446         }
 447         argv_array_clear(&args);
 448
 449         /* parse files and hunks */
 450         p = plain->buf;
 451         pend = p + plain->len;
 452         while (p != pend) {
 453                 char *eol = memchr(p, '\n', pend - p);
 454                 const char *deleted = NULL, *added = NULL, *mode_change = NULL;
 455
 456                 if (!eol)
 457                         eol = pend;
 458
 459                 if (starts_with(p, "diff ")) {
 460                         s->file_diff_nr++;
 461                         ALLOC_GROW(s->file_diff, s->file_diff_nr,
 462                                    file_diff_alloc);
 463                         file_diff = s->file_diff + s->file_diff_nr - 1;
 464                         memset(file_diff, 0, sizeof(*file_diff));
 465                         hunk = &file_diff->head;
 466                         hunk->start = p - plain->buf;
 467                         if (colored_p)
 468                                 hunk->colored_start = colored_p - colored->buf;
 469                         marker = '\0';
 470                 } else if (p == plain->buf)
 471                         BUG("diff starts with unexpected line:\n"
 472                             "%.*s\n", (int)(eol - p), p);
 473                 else if (file_diff->deleted || file_diff->added)
 474                         ; /* keep the rest of the file in a single "hunk" */
 475                 else if (starts_with(p, "@@ ") ||
 476                          (hunk == &file_diff->head &&
 477                           (skip_prefix(p, "deleted file", &deleted) ||
 478                            skip_prefix(p, "new file", &added)))) {
 479                         if (marker == '-' || marker == '+')
 480                                 /*
 481                                  * Should not happen; previous hunk did not end
 482                                  * in a context line? Handle it anyway.
 483                                  */
 484                                 hunk->splittable_into++;
 485
 486                         file_diff->hunk_nr++;
 487                         ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr,
 488                                    file_diff->hunk_alloc);
 489                         hunk = file_diff->hunk + file_diff->hunk_nr - 1;
 490                         memset(hunk, 0, sizeof(*hunk));
 491
 492                         hunk->start = p - plain->buf;
 493                         if (colored)
 494                                 hunk->colored_start = colored_p - colored->buf;
 495
 496                         if (deleted)
 497                                 file_diff->deleted = 1;
 498                         else if (added)
 499                                 file_diff->added = 1;
 500                         else if (parse_hunk_header(s, hunk) < 0)
 501                                 return -1;
 502
 503                         /*
 504                          * Start counting into how many hunks this one can be
 505                          * split
 506                          */
 507                         marker = *p;
 508                 } else if (hunk == &file_diff->head &&
 509                            skip_prefix(p, "old mode ", &mode_change) &&
 510                            is_octal(mode_change, eol - mode_change)) {
 511                         if (file_diff->mode_change)
 512                                 BUG("double mode change?\n\n%.*s",
 513                                     (int)(eol - plain->buf), plain->buf);
 514                         if (file_diff->hunk_nr++)
 515                                 BUG("mode change in the middle?\n\n%.*s",
 516                                     (int)(eol - plain->buf), plain->buf);
 517
 518                         /*
 519                          * Do *not* change `hunk`: the mode change pseudo-hunk
 520                          * is _part of_ the header "hunk".
 521                          */
 522                         file_diff->mode_change = 1;
 523                         ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr,
 524                                    file_diff->hunk_alloc);
 525                         memset(file_diff->hunk, 0, sizeof(struct hunk));
 526                         file_diff->hunk->start = p - plain->buf;
 527                         if (colored_p)
 528                                 file_diff->hunk->colored_start =
 529                                         colored_p - colored->buf;
 530                 } else if (hunk == &file_diff->head &&
 531                            skip_prefix(p, "new mode ", &mode_change) &&
 532                            is_octal(mode_change, eol - mode_change)) {
 533
 534                         /*
 535                          * Extend the "mode change" pseudo-hunk to include also
 536                          * the "new mode" line.
 537                          */
 538                         if (!file_diff->mode_change)
 539                                 BUG("'new mode' without 'old mode'?\n\n%.*s",
 540                                     (int)(eol - plain->buf), plain->buf);
 541                         if (file_diff->hunk_nr != 1)
 542                                 BUG("mode change in the middle?\n\n%.*s",
 543                                     (int)(eol - plain->buf), plain->buf);
 544                         if (p - plain->buf != file_diff->hunk->end)
 545                                 BUG("'new mode' does not immediately follow "
 546                                     "'old mode'?\n\n%.*s",
 547                                     (int)(eol - plain->buf), plain->buf);
 548                 } else if (hunk == &file_diff->head &&
 549                            starts_with(p, "Binary files "))
 550                         file_diff->binary = 1;
 551
 552                 if (!!file_diff->deleted + !!file_diff->added +
 553                     !!file_diff->mode_change > 1)
 554                         BUG("diff can only contain delete *or* add *or* a "
 555                             "mode change?!?\n%.*s",
 556                             (int)(eol - (plain->buf + file_diff->head.start)),
 557                             plain->buf + file_diff->head.start);
 558
 559                 if ((marker == '-' || marker == '+') && *p == ' ')
 560                         hunk->splittable_into++;
 561                 if (marker && *p != '\\')
 562                         marker = *p;
 563
 564                 p = eol == pend ? pend : eol + 1;
 565                 hunk->end = p - plain->buf;
 566
 567                 if (colored) {
 568                         char *colored_eol = memchr(colored_p, '\n',
 569                                                    colored_pend - colored_p);
 570                         if (colored_eol)
 571                                 colored_p = colored_eol + 1;
 572                         else if (p != pend)
 573                                 /* colored shorter than non-colored? */
 574                                 goto mismatched_output;
 575                         else
 576                                 colored_p = colored_pend;
 577
 578                         hunk->colored_end = colored_p - colored->buf;
 579                 }
 580
 581                 if (mode_change) {
 582                         if (file_diff->hunk_nr != 1)
 583                                 BUG("mode change in hunk #%d???",
 584                                     (int)file_diff->hunk_nr);
 585                         /* Adjust the end of the "mode change" pseudo-hunk */
 586                         file_diff->hunk->end = hunk->end;
 587                         if (colored)
 588                                 file_diff->hunk->colored_end = hunk->colored_end;
 589                 }
 590         }
 591
 592         if (marker == '-' || marker == '+')
 593                 /*
 594                  * Last hunk ended in non-context line (i.e. it appended lines
 595                  * to the file, so there are no trailing context lines).
 596                  */
 597                 hunk->splittable_into++;
 598
 599         /* non-colored shorter than colored? */
 600         if (colored_p != colored_pend) {
 601 mismatched_output:
 602                 error(_("mismatched output from interactive.diffFilter"));
 603                 advise(_("Your filter must maintain a one-to-one correspondence\n"
 604                          "between its input and output lines."));
 605                 return -1;
 606         }
 607
 608         return 0;
 609 }
 610
 611 static size_t find_next_line(struct strbuf *sb, size_t offset)
 612 {
 613         char *eol;
 614
 615         if (offset >= sb->len)
 616                 BUG("looking for next line beyond buffer (%d >= %d)\n%s",
 617                     (int)offset, (int)sb->len, sb->buf);
 618
 619         eol = memchr(sb->buf + offset, '\n', sb->len - offset);
 620         if (!eol)
 621                 return sb->len;
 622         return eol - sb->buf + 1;
 623 }
 624
 625 static void render_hunk(struct add_p_state *s, struct hunk *hunk,
 626                         ssize_t delta, int colored, struct strbuf *out)
 627 {
 628         struct hunk_header *header = &hunk->header;
 629
 630         if (hunk->header.old_offset != 0 || hunk->header.new_offset != 0) {
 631                 /*
 632                  * Generate the hunk header dynamically, except for special
 633                  * hunks (such as the diff header).
 634                  */
 635                 const char *p;
 636                 size_t len;
 637                 unsigned long old_offset = header->old_offset;
 638                 unsigned long new_offset = header->new_offset;
 639
 640                 if (!colored) {
 641                         p = s->plain.buf + header->extra_start;
 642                         len = header->extra_end - header->extra_start;
 643                 } else {
 644                         strbuf_addstr(out, s->s.fraginfo_color);
 645                         p = s->colored.buf + header->colored_extra_start;
 646                         len = header->colored_extra_end
 647                                 - header->colored_extra_start;
 648                 }
 649
 650                 if (s->mode->is_reverse)
 651                         old_offset -= delta;
 652                 else
 653                         new_offset += delta;
 654
 655                 strbuf_addf(out, "@@ -%lu,%lu +%lu,%lu @@",
 656                             old_offset, header->old_count,
 657                             new_offset, header->new_count);
 658                 if (len)
 659                         strbuf_add(out, p, len);
 660                 else if (colored)
 661                         strbuf_addf(out, "%s\n", GIT_COLOR_RESET);
 662                 else
 663                         strbuf_addch(out, '\n');
 664         }
 665
 666         if (colored)
 667                 strbuf_add(out, s->colored.buf + hunk->colored_start,
 668                            hunk->colored_end - hunk->colored_start);
 669         else
 670                 strbuf_add(out, s->plain.buf + hunk->start,
 671                            hunk->end - hunk->start);
 672 }
 673
 674 static void render_diff_header(struct add_p_state *s,
 675                                struct file_diff *file_diff, int colored,
 676                                struct strbuf *out)
 677 {
 678         /*
 679          * If there was a mode change, the first hunk is a pseudo hunk that
 680          * corresponds to the mode line in the header. If the user did not want
 681          * to stage that "hunk", we actually have to cut it out from the header.
 682          */
 683         int skip_mode_change =
 684                 file_diff->mode_change && file_diff->hunk->use != USE_HUNK;
 685         struct hunk *head = &file_diff->head, *first = file_diff->hunk;
 686
 687         if (!skip_mode_change) {
 688                 render_hunk(s, head, 0, colored, out);
 689                 return;
 690         }
 691
 692         if (colored) {
 693                 const char *p = s->colored.buf;
 694
 695                 strbuf_add(out, p + head->colored_start,
 696                             first->colored_start - head->colored_start);
 697                 strbuf_add(out, p + first->colored_end,
 698                             head->colored_end - first->colored_end);
 699         } else {
 700                 const char *p = s->plain.buf;
 701
 702                 strbuf_add(out, p + head->start, first->start - head->start);
 703                 strbuf_add(out, p + first->end, head->end - first->end);
 704         }
 705 }
 706
 707 /* Coalesce hunks again that were split */
 708 static int merge_hunks(struct add_p_state *s, struct file_diff *file_diff,
 709                        size_t *hunk_index, int use_all, struct hunk *merged)
 710 {
 711         size_t i = *hunk_index, delta;
 712         struct hunk *hunk = file_diff->hunk + i;
 713         /* `header` corresponds to the merged hunk */
 714         struct hunk_header *header = &merged->header, *next;
 715
 716         if (!use_all && hunk->use != USE_HUNK)
 717                 return 0;
 718
 719         *merged = *hunk;
 720         /* We simply skip the colored part (if any) when merging hunks */
 721         merged->colored_start = merged->colored_end = 0;
 722
 723         for (; i + 1 < file_diff->hunk_nr; i++) {
 724                 hunk++;
 725                 next = &hunk->header;
 726
 727                 /*
 728                  * Stop merging hunks when:
 729                  *
 730                  * - the hunk is not selected for use, or
 731                  * - the hunk does not overlap with the already-merged hunk(s)
 732                  */
 733                 if ((!use_all && hunk->use != USE_HUNK) ||
 734                     header->new_offset >= next->new_offset + merged->delta ||
 735                     header->new_offset + header->new_count
 736                     < next->new_offset + merged->delta)
 737                         break;
 738
 739                 /*
 740                  * If the hunks were not edited, and overlap, we can simply
 741                  * extend the line range.
 742                  */
 743                 if (merged->start < hunk->start && merged->end > hunk->start) {
 744                         merged->end = hunk->end;
 745                         merged->colored_end = hunk->colored_end;
 746                         delta = 0;
 747                 } else {
 748                         const char *plain = s->plain.buf;
 749                         size_t  overlapping_line_count = header->new_offset
 750                                 + header->new_count - merged->delta
 751                                 - next->new_offset;
 752                         size_t overlap_end = hunk->start;
 753                         size_t overlap_start = overlap_end;
 754                         size_t overlap_next, len, j;
 755
 756                         /*
 757                          * One of the hunks was edited: the modified hunk was
 758                          * appended to the strbuf `s->plain`.
 759                          *
 760                          * Let's ensure that at least the last context line of
 761                          * the first hunk overlaps with the corresponding line
 762                          * of the second hunk, and then merge.
 763                          */
 764                         for (j = 0; j < overlapping_line_count; j++) {
 765                                 overlap_next = find_next_line(&s->plain,
 766                                                               overlap_end);
 767
 768                                 if (overlap_next > hunk->end)
 769                                         BUG("failed to find %d context lines "
 770                                             "in:\n%.*s",
 771                                             (int)overlapping_line_count,
 772                                             (int)(hunk->end - hunk->start),
 773                                             plain + hunk->start);
 774
 775                                 if (plain[overlap_end] != ' ')
 776                                         return error(_("expected context line "
 777                                                        "#%d in\n%.*s"),
 778                                                      (int)(j + 1),
 779                                                      (int)(hunk->end
 780                                                            - hunk->start),
 781                                                      plain + hunk->start);
 782
 783                                 overlap_start = overlap_end;
 784                                 overlap_end = overlap_next;
 785                         }
 786                         len = overlap_end - overlap_start;
 787
 788                         if (len > merged->end - merged->start ||
 789                             memcmp(plain + merged->end - len,
 790                                    plain + overlap_start, len))
 791                                 return error(_("hunks do not overlap:\n%.*s\n"
 792                                                "\tdoes not end with:\n%.*s"),
 793                                              (int)(merged->end - merged->start),
 794                                              plain + merged->start,
 795                                              (int)len, plain + overlap_start);
 796
 797                         /*
 798                          * Since the start-end ranges are not adjacent, we
 799                          * cannot simply take the union of the ranges. To
 800                          * address that, we temporarily append the union of the
 801                          * lines to the `plain` strbuf.
 802                          */
 803                         if (merged->end != s->plain.len) {
 804                                 size_t start = s->plain.len;
 805
 806                                 strbuf_add(&s->plain, plain + merged->start,
 807                                            merged->end - merged->start);
 808                                 plain = s->plain.buf;
 809                                 merged->start = start;
 810                                 merged->end = s->plain.len;
 811                         }
 812
 813                         strbuf_add(&s->plain,
 814                                    plain + overlap_end,
 815                                    hunk->end - overlap_end);
 816                         merged->end = s->plain.len;
 817                         merged->splittable_into += hunk->splittable_into;
 818                         delta = merged->delta;
 819                         merged->delta += hunk->delta;
 820                 }
 821
 822                 header->old_count = next->old_offset + next->old_count
 823                         - header->old_offset;
 824                 header->new_count = next->new_offset + delta
 825                         + next->new_count - header->new_offset;
 826         }
 827
 828         if (i == *hunk_index)
 829                 return 0;
 830
 831         *hunk_index = i;
 832         return 1;
 833 }
 834
 835 static void reassemble_patch(struct add_p_state *s,
 836                              struct file_diff *file_diff, int use_all,
 837                              struct strbuf *out)
 838 {
 839         struct hunk *hunk;
 840         size_t save_len = s->plain.len, i;
 841         ssize_t delta = 0;
 842
 843         render_diff_header(s, file_diff, 0, out);
 844
 845         for (i = file_diff->mode_change; i < file_diff->hunk_nr; i++) {
 846                 struct hunk merged = { 0 };
 847
 848                 hunk = file_diff->hunk + i;
 849                 if (!use_all && hunk->use != USE_HUNK)
 850                         delta += hunk->header.old_count
 851                                 - hunk->header.new_count;
 852                 else {
 853                         /* merge overlapping hunks into a temporary hunk */
 854                         if (merge_hunks(s, file_diff, &i, use_all, &merged))
 855                                 hunk = &merged;
 856
 857                         render_hunk(s, hunk, delta, 0, out);
 858
 859                         /*
 860                          * In case `merge_hunks()` used `plain` as a scratch
 861                          * pad (this happens when an edited hunk had to be
 862                          * coalesced with another hunk).
 863                          */
 864                         strbuf_setlen(&s->plain, save_len);
 865
 866                         delta += hunk->delta;
 867                 }
 868         }
 869 }
 870
 871 static int split_hunk(struct add_p_state *s, struct file_diff *file_diff,
 872                        size_t hunk_index)
 873 {
 874         int colored = !!s->colored.len, first = 1;
 875         struct hunk *hunk = file_diff->hunk + hunk_index;
 876         size_t splittable_into;
 877         size_t end, colored_end, current, colored_current = 0, context_line_count;
 878         struct hunk_header remaining, *header;
 879         char marker, ch;
 880
 881         if (hunk_index >= file_diff->hunk_nr)
 882                 BUG("invalid hunk index: %d (must be >= 0 and < %d)",
 883                     (int)hunk_index, (int)file_diff->hunk_nr);
 884
 885         if (hunk->splittable_into < 2)
 886                 return 0;
 887         splittable_into = hunk->splittable_into;
 888
 889         end = hunk->end;
 890         colored_end = hunk->colored_end;
 891
 892         remaining = hunk->header;
 893
 894         file_diff->hunk_nr += splittable_into - 1;
 895         ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr, file_diff->hunk_alloc);
 896         if (hunk_index + splittable_into < file_diff->hunk_nr)
 897                 memmove(file_diff->hunk + hunk_index + splittable_into,
 898                         file_diff->hunk + hunk_index + 1,
 899                         (file_diff->hunk_nr - hunk_index - splittable_into)
 900                         * sizeof(*hunk));
 901         hunk = file_diff->hunk + hunk_index;
 902         hunk->splittable_into = 1;
 903         memset(hunk + 1, 0, (splittable_into - 1) * sizeof(*hunk));
 904
 905         header = &hunk->header;
 906         header->old_count = header->new_count = 0;
 907
 908         current = hunk->start;
 909         if (colored)
 910                 colored_current = hunk->colored_start;
 911         marker = '\0';
 912         context_line_count = 0;
 913
 914         while (splittable_into > 1) {
 915                 ch = s->plain.buf[current];
 916
 917                 if (!ch)
 918                         BUG("buffer overrun while splitting hunks");
 919
 920                 /*
 921                  * Is this the first context line after a chain of +/- lines?
 922                  * Then record the start of the next split hunk.
 923                  */
 924                 if ((marker == '-' || marker == '+') && ch == ' ') {
 925                         first = 0;
 926                         hunk[1].start = current;
 927                         if (colored)
 928                                 hunk[1].colored_start = colored_current;
 929                         context_line_count = 0;
 930                 }
 931
 932                 /*
 933                  * Was the previous line a +/- one? Alternatively, is this the
 934                  * first line (and not a +/- one)?
 935                  *
 936                  * Then just increment the appropriate counter and continue
 937                  * with the next line.
 938                  */
 939                 if (marker != ' ' || (ch != '-' && ch != '+')) {
 940 next_hunk_line:
 941                         /* Comment lines are attached to the previous line */
 942                         if (ch == '\\')
 943                                 ch = marker ? marker : ' ';
 944
 945                         /* current hunk not done yet */
 946                         if (ch == ' ')
 947                                 context_line_count++;
 948                         else if (ch == '-')
 949                                 header->old_count++;
 950                         else if (ch == '+')
 951                                 header->new_count++;
 952                         else
 953                                 BUG("unhandled diff marker: '%c'", ch);
 954                         marker = ch;
 955                         current = find_next_line(&s->plain, current);
 956                         if (colored)
 957                                 colored_current =
 958                                         find_next_line(&s->colored,
 959                                                        colored_current);
 960                         continue;
 961                 }
 962
 963                 /*
 964                  * We got us the start of a new hunk!
 965                  *
 966                  * This is a context line, so it is shared with the previous
 967                  * hunk, if any.
 968                  */
 969
 970                 if (first) {
 971                         if (header->old_count || header->new_count)
 972                                 BUG("counts are off: %d/%d",
 973                                     (int)header->old_count,
 974                                     (int)header->new_count);
 975
 976                         header->old_count = context_line_count;
 977                         header->new_count = context_line_count;
 978                         context_line_count = 0;
 979                         first = 0;
 980                         goto next_hunk_line;
 981                 }
 982
 983                 remaining.old_offset += header->old_count;
 984                 remaining.old_count -= header->old_count;
 985                 remaining.new_offset += header->new_count;
 986                 remaining.new_count -= header->new_count;
 987
 988                 /* initialize next hunk header's offsets */
 989                 hunk[1].header.old_offset =
 990                         header->old_offset + header->old_count;
 991                 hunk[1].header.new_offset =
 992                         header->new_offset + header->new_count;
 993
 994                 /* add one split hunk */
 995                 header->old_count += context_line_count;
 996                 header->new_count += context_line_count;
 997
 998                 hunk->end = current;
 999                 if (colored)
1000                         hunk->colored_end = colored_current;
1001
1002                 hunk++;
1003                 hunk->splittable_into = 1;
1004                 hunk->use = hunk[-1].use;
1005                 header = &hunk->header;
1006
1007                 header->old_count = header->new_count = context_line_count;
1008                 context_line_count = 0;
1009
1010                 splittable_into--;
1011                 marker = ch;
1012         }
1013
1014         /* last hunk simply gets the rest */
1015         if (header->old_offset != remaining.old_offset)
1016                 BUG("miscounted old_offset: %lu != %lu",
1017                     header->old_offset, remaining.old_offset);
1018         if (header->new_offset != remaining.new_offset)
1019                 BUG("miscounted new_offset: %lu != %lu",
1020                     header->new_offset, remaining.new_offset);
1021         header->old_count = remaining.old_count;
1022         header->new_count = remaining.new_count;
1023         hunk->end = end;
1024         if (colored)
1025                 hunk->colored_end = colored_end;
1026
1027         return 0;
1028 }
1029
1030 static void recolor_hunk(struct add_p_state *s, struct hunk *hunk)
1031 {
1032         const char *plain = s->plain.buf;
1033         size_t current, eol, next;
1034
1035         if (!s->colored.len)
1036                 return;
1037
1038         hunk->colored_start = s->colored.len;
1039         for (current = hunk->start; current < hunk->end; ) {
1040                 for (eol = current; eol < hunk->end; eol++)
1041                         if (plain[eol] == '\n')
1042                                 break;
1043                 next = eol + (eol < hunk->end);
1044                 if (eol > current && plain[eol - 1] == '\r')
1045                         eol--;
1046
1047                 strbuf_addstr(&s->colored,
1048                               plain[current] == '-' ?
1049                               s->s.file_old_color :
1050                               plain[current] == '+' ?
1051                               s->s.file_new_color :
1052                               s->s.context_color);
1053                 strbuf_add(&s->colored, plain + current, eol - current);
1054                 strbuf_addstr(&s->colored, GIT_COLOR_RESET);
1055                 if (next > eol)
1056                         strbuf_add(&s->colored, plain + eol, next - eol);
1057                 current = next;
1058         }
1059         hunk->colored_end = s->colored.len;
1060 }
1061
1062 static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
1063 {
1064         size_t i;
1065
1066         strbuf_reset(&s->buf);
1067         strbuf_commented_addf(&s->buf, _("Manual hunk edit mode -- see bottom for "
1068                                       "a quick guide.\n"));
1069         render_hunk(s, hunk, 0, 0, &s->buf);
1070         strbuf_commented_addf(&s->buf,
1071                               _("---\n"
1072                                 "To remove '%c' lines, make them ' ' lines "
1073                                 "(context).\n"
1074                                 "To remove '%c' lines, delete them.\n"
1075                                 "Lines starting with %c will be removed.\n"),
1076                               s->mode->is_reverse ? '+' : '-',
1077                               s->mode->is_reverse ? '-' : '+',
1078                               comment_line_char);
1079         strbuf_commented_addf(&s->buf, "%s", _(s->mode->edit_hunk_hint));
1080         /*
1081          * TRANSLATORS: 'it' refers to the patch mentioned in the previous
1082          * messages.
1083          */
1084         strbuf_commented_addf(&s->buf,
1085                               _("If it does not apply cleanly, you will be "
1086                                 "given an opportunity to\n"
1087                                 "edit again.  If all lines of the hunk are "
1088                                 "removed, then the edit is\n"
1089                                 "aborted and the hunk is left unchanged.\n"));
1090
1091         if (strbuf_edit_interactively(&s->buf, "addp-hunk-edit.diff", NULL) < 0)
1092                 return -1;
1093
1094         /* strip out commented lines */
1095         hunk->start = s->plain.len;
1096         for (i = 0; i < s->buf.len; ) {
1097                 size_t next = find_next_line(&s->buf, i);
1098
1099                 if (s->buf.buf[i] != comment_line_char)
1100                         strbuf_add(&s->plain, s->buf.buf + i, next - i);
1101                 i = next;
1102         }
1103
1104         hunk->end = s->plain.len;
1105         if (hunk->end == hunk->start)
1106                 /* The user aborted editing by deleting everything */
1107                 return 0;
1108
1109         recolor_hunk(s, hunk);
1110
1111         /*
1112          * If the hunk header is intact, parse it, otherwise simply use the
1113          * hunk header prior to editing (which will adjust `hunk->start` to
1114          * skip the hunk header).
1115          */
1116         if (s->plain.buf[hunk->start] == '@' &&
1117             parse_hunk_header(s, hunk) < 0)
1118                 return error(_("could not parse hunk header"));
1119
1120         return 1;
1121 }
1122
1123 static ssize_t recount_edited_hunk(struct add_p_state *s, struct hunk *hunk,
1124                                    size_t orig_old_count, size_t orig_new_count)
1125 {
1126         struct hunk_header *header = &hunk->header;
1127         size_t i;
1128
1129         header->old_count = header->new_count = 0;
1130         for (i = hunk->start; i < hunk->end; ) {
1131                 switch (s->plain.buf[i]) {
1132                 case '-':
1133                         header->old_count++;
1134                         break;
1135                 case '+':
1136                         header->new_count++;
1137                         break;
1138                 case ' ': case '\r': case '\n':
1139                         header->old_count++;
1140                         header->new_count++;
1141                         break;
1142                 }
1143
1144                 i = find_next_line(&s->plain, i);
1145         }
1146
1147         return orig_old_count - orig_new_count
1148                 - header->old_count + header->new_count;
1149 }
1150
1151 static int run_apply_check(struct add_p_state *s,
1152                            struct file_diff *file_diff)
1153 {
1154         struct child_process cp = CHILD_PROCESS_INIT;
1155
1156         strbuf_reset(&s->buf);
1157         reassemble_patch(s, file_diff, 1, &s->buf);
1158
1159         setup_child_process(s, &cp,
1160                             "apply", "--check", NULL);
1161         argv_array_pushv(&cp.args, s->mode->apply_check_args);
1162         if (pipe_command(&cp, s->buf.buf, s->buf.len, NULL, 0, NULL, 0))
1163                 return error(_("'git apply --cached' failed"));
1164
1165         return 0;
1166 }
1167
1168 static int read_single_character(struct add_p_state *s)
1169 {
1170         if (s->s.use_single_key) {
1171                 int res = read_key_without_echo(&s->answer);
1172                 printf("%s\n", res == EOF ? "" : s->answer.buf);
1173                 return res;
1174         }
1175
1176         if (git_read_line_interactively(&s->answer) == EOF)
1177                 return EOF;
1178         return 0;
1179 }
1180
1181 static int prompt_yesno(struct add_p_state *s, const char *prompt)
1182 {
1183         for (;;) {
1184                 color_fprintf(stdout, s->s.prompt_color, "%s", _(prompt));
1185                 fflush(stdout);
1186                 if (read_single_character(s) == EOF)
1187                         return -1;
1188                 switch (tolower(s->answer.buf[0])) {
1189                 case 'n': return 0;
1190                 case 'y': return 1;
1191                 }
1192         }
1193 }
1194
1195 static int edit_hunk_loop(struct add_p_state *s,
1196                           struct file_diff *file_diff, struct hunk *hunk)
1197 {
1198         size_t plain_len = s->plain.len, colored_len = s->colored.len;
1199         struct hunk backup;
1200
1201         backup = *hunk;
1202
1203         for (;;) {
1204                 int res = edit_hunk_manually(s, hunk);
1205                 if (res == 0) {
1206                         /* abandonded */
1207                         *hunk = backup;
1208                         return -1;
1209                 }
1210
1211                 if (res > 0) {
1212                         hunk->delta +=
1213                                 recount_edited_hunk(s, hunk,
1214                                                     backup.header.old_count,
1215                                                     backup.header.new_count);
1216                         if (!run_apply_check(s, file_diff))
1217                                 return 0;
1218                 }
1219
1220                 /* Drop edits (they were appended to s->plain) */
1221                 strbuf_setlen(&s->plain, plain_len);
1222                 strbuf_setlen(&s->colored, colored_len);
1223                 *hunk = backup;
1224
1225                 /*
1226                  * TRANSLATORS: do not translate [y/n]
1227                  * The program will only accept that input at this point.
1228                  * Consider translating (saying "no" discards!) as
1229                  * (saying "n" for "no" discards!) if the translation
1230                  * of the word "no" does not start with n.
1231                  */
1232                 res = prompt_yesno(s, _("Your edited hunk does not apply. "
1233                                         "Edit again (saying \"no\" discards!) "
1234                                         "[y/n]? "));
1235                 if (res < 1)
1236                         return -1;
1237         }
1238 }
1239
1240 static int apply_for_checkout(struct add_p_state *s, struct strbuf *diff,
1241                               int is_reverse)
1242 {
1243         const char *reverse = is_reverse ? "-R" : NULL;
1244         struct child_process check_index = CHILD_PROCESS_INIT;
1245         struct child_process check_worktree = CHILD_PROCESS_INIT;
1246         struct child_process apply_index = CHILD_PROCESS_INIT;
1247         struct child_process apply_worktree = CHILD_PROCESS_INIT;
1248         int applies_index, applies_worktree;
1249
1250         setup_child_process(s, &check_index,
1251                             "apply", "--cached", "--check", reverse, NULL);
1252         applies_index = !pipe_command(&check_index, diff->buf, diff->len,
1253                                       NULL, 0, NULL, 0);
1254
1255         setup_child_process(s, &check_worktree,
1256                             "apply", "--check", reverse, NULL);
1257         applies_worktree = !pipe_command(&check_worktree, diff->buf, diff->len,
1258                                          NULL, 0, NULL, 0);
1259
1260         if (applies_worktree && applies_index) {
1261                 setup_child_process(s, &apply_index,
1262                                     "apply", "--cached", reverse, NULL);
1263                 pipe_command(&apply_index, diff->buf, diff->len,
1264                              NULL, 0, NULL, 0);
1265
1266                 setup_child_process(s, &apply_worktree,
1267                                     "apply", reverse, NULL);
1268                 pipe_command(&apply_worktree, diff->buf, diff->len,
1269                              NULL, 0, NULL, 0);
1270
1271                 return 1;
1272         }
1273
1274         if (!applies_index) {
1275                 err(s, _("The selected hunks do not apply to the index!"));
1276                 if (prompt_yesno(s, _("Apply them to the worktree "
1277                                           "anyway? ")) > 0) {
1278                         setup_child_process(s, &apply_worktree,
1279                                             "apply", reverse, NULL);
1280                         return pipe_command(&apply_worktree, diff->buf,
1281                                             diff->len, NULL, 0, NULL, 0);
1282                 }
1283                 err(s, _("Nothing was applied.\n"));
1284         } else
1285                 /* As a last resort, show the diff to the user */
1286                 fwrite(diff->buf, diff->len, 1, stderr);
1287
1288         return 0;
1289 }
1290
1291 #define SUMMARY_HEADER_WIDTH 20
1292 #define SUMMARY_LINE_WIDTH 80
1293 static void summarize_hunk(struct add_p_state *s, struct hunk *hunk,
1294                            struct strbuf *out)
1295 {
1296         struct hunk_header *header = &hunk->header;
1297         struct strbuf *plain = &s->plain;
1298         size_t len = out->len, i;
1299
1300         strbuf_addf(out, " -%lu,%lu +%lu,%lu ",
1301                     header->old_offset, header->old_count,
1302                     header->new_offset, header->new_count);
1303         if (out->len - len < SUMMARY_HEADER_WIDTH)
1304                 strbuf_addchars(out, ' ',
1305                                 SUMMARY_HEADER_WIDTH + len - out->len);
1306         for (i = hunk->start; i < hunk->end; i = find_next_line(plain, i))
1307                 if (plain->buf[i] != ' ')
1308                         break;
1309         if (i < hunk->end)
1310                 strbuf_add(out, plain->buf + i, find_next_line(plain, i) - i);
1311         if (out->len - len > SUMMARY_LINE_WIDTH)
1312                 strbuf_setlen(out, len + SUMMARY_LINE_WIDTH);
1313         strbuf_complete_line(out);
1314 }
1315
1316 #define DISPLAY_HUNKS_LINES 20
1317 static size_t display_hunks(struct add_p_state *s,
1318                             struct file_diff *file_diff, size_t start_index)
1319 {
1320         size_t end_index = start_index + DISPLAY_HUNKS_LINES;
1321
1322         if (end_index > file_diff->hunk_nr)
1323                 end_index = file_diff->hunk_nr;
1324
1325         while (start_index < end_index) {
1326                 struct hunk *hunk = file_diff->hunk + start_index++;
1327
1328                 strbuf_reset(&s->buf);
1329                 strbuf_addf(&s->buf, "%c%2d: ", hunk->use == USE_HUNK ? '+'
1330                             : hunk->use == SKIP_HUNK ? '-' : ' ',
1331                             (int)start_index);
1332                 summarize_hunk(s, hunk, &s->buf);
1333                 fputs(s->buf.buf, stdout);
1334         }
1335
1336         return end_index;
1337 }
1338
1339 static const char help_patch_remainder[] =
1340 N_("j - leave this hunk undecided, see next undecided hunk\n"
1341    "J - leave this hunk undecided, see next hunk\n"
1342    "k - leave this hunk undecided, see previous undecided hunk\n"
1343    "K - leave this hunk undecided, see previous hunk\n"
1344    "g - select a hunk to go to\n"
1345    "/ - search for a hunk matching the given regex\n"
1346    "s - split the current hunk into smaller hunks\n"
1347    "e - manually edit the current hunk\n"
1348    "? - print help\n");
1349
1350 static int patch_update_file(struct add_p_state *s,
1351                              struct file_diff *file_diff)
1352 {
1353         size_t hunk_index = 0;
1354         ssize_t i, undecided_previous, undecided_next;
1355         struct hunk *hunk;
1356         char ch;
1357         struct child_process cp = CHILD_PROCESS_INIT;
1358         int colored = !!s->colored.len, quit = 0;
1359         enum prompt_mode_type prompt_mode_type;
1360
1361         if (!file_diff->hunk_nr)
1362                 return 0;
1363
1364         strbuf_reset(&s->buf);
1365         render_diff_header(s, file_diff, colored, &s->buf);
1366         fputs(s->buf.buf, stdout);
1367         for (;;) {
1368                 if (hunk_index >= file_diff->hunk_nr)
1369                         hunk_index = 0;
1370                 hunk = file_diff->hunk + hunk_index;
1371
1372                 undecided_previous = -1;
1373                 for (i = hunk_index - 1; i >= 0; i--)
1374                         if (file_diff->hunk[i].use == UNDECIDED_HUNK) {
1375                                 undecided_previous = i;
1376                                 break;
1377                         }
1378
1379                 undecided_next = -1;
1380                 for (i = hunk_index + 1; i < file_diff->hunk_nr; i++)
1381                         if (file_diff->hunk[i].use == UNDECIDED_HUNK) {
1382                                 undecided_next = i;
1383                                 break;
1384                         }
1385
1386                 /* Everything decided? */
1387                 if (undecided_previous < 0 && undecided_next < 0 &&
1388                     hunk->use != UNDECIDED_HUNK)
1389                         break;
1390
1391                 strbuf_reset(&s->buf);
1392                 render_hunk(s, hunk, 0, colored, &s->buf);
1393                 fputs(s->buf.buf, stdout);
1394
1395                 strbuf_reset(&s->buf);
1396                 if (undecided_previous >= 0)
1397                         strbuf_addstr(&s->buf, ",k");
1398                 if (hunk_index)
1399                         strbuf_addstr(&s->buf, ",K");
1400                 if (undecided_next >= 0)
1401                         strbuf_addstr(&s->buf, ",j");
1402                 if (hunk_index + 1 < file_diff->hunk_nr)
1403                         strbuf_addstr(&s->buf, ",J");
1404                 if (file_diff->hunk_nr > 1)
1405                         strbuf_addstr(&s->buf, ",g,/");
1406                 if (hunk->splittable_into > 1)
1407                         strbuf_addstr(&s->buf, ",s");
1408                 if (hunk_index + 1 > file_diff->mode_change &&
1409                     !file_diff->deleted)
1410                         strbuf_addstr(&s->buf, ",e");
1411
1412                 if (file_diff->deleted)
1413                         prompt_mode_type = PROMPT_DELETION;
1414                 else if (file_diff->added)
1415                         prompt_mode_type = PROMPT_ADDITION;
1416                 else if (file_diff->mode_change && !hunk_index)
1417                         prompt_mode_type = PROMPT_MODE_CHANGE;
1418                 else
1419                         prompt_mode_type = PROMPT_HUNK;
1420
1421                 color_fprintf(stdout, s->s.prompt_color,
1422                               "(%"PRIuMAX"/%"PRIuMAX") ",
1423                               (uintmax_t)hunk_index + 1,
1424                               (uintmax_t)file_diff->hunk_nr);
1425                 color_fprintf(stdout, s->s.prompt_color,
1426                               _(s->mode->prompt_mode[prompt_mode_type]),
1427                               s->buf.buf);
1428                 fflush(stdout);
1429                 if (read_single_character(s) == EOF)
1430                         break;
1431
1432                 if (!s->answer.len)
1433                         continue;
1434                 ch = tolower(s->answer.buf[0]);
1435                 if (ch == 'y') {
1436                         hunk->use = USE_HUNK;
1437 soft_increment:
1438                         hunk_index = undecided_next < 0 ?
1439                                 file_diff->hunk_nr : undecided_next;
1440                 } else if (ch == 'n') {
1441                         hunk->use = SKIP_HUNK;
1442                         goto soft_increment;
1443                 } else if (ch == 'a') {
1444                         for (; hunk_index < file_diff->hunk_nr; hunk_index++) {
1445                                 hunk = file_diff->hunk + hunk_index;
1446                                 if (hunk->use == UNDECIDED_HUNK)
1447                                         hunk->use = USE_HUNK;
1448                         }
1449                 } else if (ch == 'd' || ch == 'q') {
1450                         for (; hunk_index < file_diff->hunk_nr; hunk_index++) {
1451                                 hunk = file_diff->hunk + hunk_index;
1452                                 if (hunk->use == UNDECIDED_HUNK)
1453                                         hunk->use = SKIP_HUNK;
1454                         }
1455                         if (ch == 'q') {
1456                                 quit = 1;
1457                                 break;
1458                         }
1459                 } else if (s->answer.buf[0] == 'K') {
1460                         if (hunk_index)
1461                                 hunk_index--;
1462                         else
1463                                 err(s, _("No previous hunk"));
1464                 } else if (s->answer.buf[0] == 'J') {
1465                         if (hunk_index + 1 < file_diff->hunk_nr)
1466                                 hunk_index++;
1467                         else
1468                                 err(s, _("No next hunk"));
1469                 } else if (s->answer.buf[0] == 'k') {
1470                         if (undecided_previous >= 0)
1471                                 hunk_index = undecided_previous;
1472                         else
1473                                 err(s, _("No previous hunk"));
1474                 } else if (s->answer.buf[0] == 'j') {
1475                         if (undecided_next >= 0)
1476                                 hunk_index = undecided_next;
1477                         else
1478                                 err(s, _("No next hunk"));
1479                 } else if (s->answer.buf[0] == 'g') {
1480                         char *pend;
1481                         unsigned long response;
1482
1483                         if (file_diff->hunk_nr < 2) {
1484                                 err(s, _("No other hunks to goto"));
1485                                 continue;
1486                         }
1487                         strbuf_remove(&s->answer, 0, 1);
1488                         strbuf_trim(&s->answer);
1489                         i = hunk_index - DISPLAY_HUNKS_LINES / 2;
1490                         if (i < file_diff->mode_change)
1491                                 i = file_diff->mode_change;
1492                         while (s->answer.len == 0) {
1493                                 i = display_hunks(s, file_diff, i);
1494                                 printf("%s", i < file_diff->hunk_nr ?
1495                                        _("go to which hunk (<ret> to see "
1496                                          "more)? ") : _("go to which hunk? "));
1497                                 fflush(stdout);
1498                                 if (strbuf_getline(&s->answer,
1499                                                    stdin) == EOF)
1500                                         break;
1501                                 strbuf_trim_trailing_newline(&s->answer);
1502                         }
1503
1504                         strbuf_trim(&s->answer);
1505                         response = strtoul(s->answer.buf, &pend, 10);
1506                         if (*pend || pend == s->answer.buf)
1507                                 err(s, _("Invalid number: '%s'"),
1508                                     s->answer.buf);
1509                         else if (0 < response && response <= file_diff->hunk_nr)
1510                                 hunk_index = response - 1;
1511                         else
1512                                 err(s, Q_("Sorry, only %d hunk available.",
1513                                           "Sorry, only %d hunks available.",
1514                                           file_diff->hunk_nr),
1515                                     (int)file_diff->hunk_nr);
1516                 } else if (s->answer.buf[0] == '/') {
1517                         regex_t regex;
1518                         int ret;
1519
1520                         if (file_diff->hunk_nr < 2) {
1521                                 err(s, _("No other hunks to search"));
1522                                 continue;
1523                         }
1524                         strbuf_remove(&s->answer, 0, 1);
1525                         strbuf_trim_trailing_newline(&s->answer);
1526                         if (s->answer.len == 0) {
1527                                 printf("%s", _("search for regex? "));
1528                                 fflush(stdout);
1529                                 if (strbuf_getline(&s->answer,
1530                                                    stdin) == EOF)
1531                                         break;
1532                                 strbuf_trim_trailing_newline(&s->answer);
1533                                 if (s->answer.len == 0)
1534                                         continue;
1535                         }
1536                         ret = regcomp(&regex, s->answer.buf,
1537                                       REG_EXTENDED | REG_NOSUB | REG_NEWLINE);
1538                         if (ret) {
1539                                 char errbuf[1024];
1540
1541                                 regerror(ret, &regex, errbuf, sizeof(errbuf));
1542                                 err(s, _("Malformed search regexp %s: %s"),
1543                                     s->answer.buf, errbuf);
1544                                 continue;
1545                         }
1546                         i = hunk_index;
1547                         for (;;) {
1548                                 /* render the hunk into a scratch buffer */
1549                                 render_hunk(s, file_diff->hunk + i, 0, 0,
1550                                             &s->buf);
1551                                 if (regexec(&regex, s->buf.buf, 0, NULL, 0)
1552                                     != REG_NOMATCH)
1553                                         break;
1554                                 i++;
1555                                 if (i == file_diff->hunk_nr)
1556                                         i = 0;
1557                                 if (i != hunk_index)
1558                                         continue;
1559                                 err(s, _("No hunk matches the given pattern"));
1560                                 break;
1561                         }
1562                         hunk_index = i;
1563                 } else if (s->answer.buf[0] == 's') {
1564                         size_t splittable_into = hunk->splittable_into;
1565                         if (splittable_into < 2)
1566                                 err(s, _("Sorry, cannot split this hunk"));
1567                         else if (!split_hunk(s, file_diff,
1568                                              hunk - file_diff->hunk))
1569                                 color_fprintf_ln(stdout, s->s.header_color,
1570                                                  _("Split into %d hunks."),
1571                                                  (int)splittable_into);
1572                 } else if (s->answer.buf[0] == 'e') {
1573                         if (hunk_index + 1 == file_diff->mode_change)
1574                                 err(s, _("Sorry, cannot edit this hunk"));
1575                         else if (edit_hunk_loop(s, file_diff, hunk) >= 0) {
1576                                 hunk->use = USE_HUNK;
1577                                 goto soft_increment;
1578                         }
1579                 } else {
1580                         const char *p = _(help_patch_remainder), *eol = p;
1581
1582                         color_fprintf(stdout, s->s.help_color, "%s",
1583                                       _(s->mode->help_patch_text));
1584
1585                         /*
1586                          * Show only those lines of the remainder that are
1587                          * actually applicable with the current hunk.
1588                          */
1589                         for (; *p; p = eol + (*eol == '\n')) {
1590                                 eol = strchrnul(p, '\n');
1591
1592                                 /*
1593                                  * `s->buf` still contains the part of the
1594                                  * commands shown in the prompt that are not
1595                                  * always available.
1596                                  */
1597                                 if (*p != '?' && !strchr(s->buf.buf, *p))
1598                                         continue;
1599
1600                                 color_fprintf_ln(stdout, s->s.help_color,
1601                                                  "%.*s", (int)(eol - p), p);
1602                         }
1603                 }
1604         }
1605
1606         /* Any hunk to be used? */
1607         for (i = 0; i < file_diff->hunk_nr; i++)
1608                 if (file_diff->hunk[i].use == USE_HUNK)
1609                         break;
1610
1611         if (i < file_diff->hunk_nr) {
1612                 /* At least one hunk selected: apply */
1613                 strbuf_reset(&s->buf);
1614                 reassemble_patch(s, file_diff, 0, &s->buf);
1615
1616                 discard_index(s->s.r->index);
1617                 if (s->mode->apply_for_checkout)
1618                         apply_for_checkout(s, &s->buf,
1619                                            s->mode->is_reverse);
1620                 else {
1621                         setup_child_process(s, &cp, "apply", NULL);
1622                         argv_array_pushv(&cp.args, s->mode->apply_args);
1623                         if (pipe_command(&cp, s->buf.buf, s->buf.len,
1624                                          NULL, 0, NULL, 0))
1625                                 error(_("'git apply' failed"));
1626                 }
1627                 if (!repo_read_index(s->s.r))
1628                         repo_refresh_and_write_index(s->s.r, REFRESH_QUIET, 0,
1629                                                      1, NULL, NULL, NULL);
1630         }
1631
1632         putchar('\n');
1633         return quit;
1634 }
1635
1636 int run_add_p(struct repository *r, enum add_p_mode mode,
1637               const char *revision, const struct pathspec *ps)
1638 {
1639         struct add_p_state s = {
1640                 { r }, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
1641         };
1642         size_t i, binary_count = 0;
1643
1644         init_add_i_state(&s.s, r);
1645
1646         if (mode == ADD_P_STASH)
1647                 s.mode = &patch_mode_stash;
1648         else if (mode == ADD_P_RESET) {
1649                 if (!revision || !strcmp(revision, "HEAD"))
1650                         s.mode = &patch_mode_reset_head;
1651                 else
1652                         s.mode = &patch_mode_reset_nothead;
1653         } else if (mode == ADD_P_CHECKOUT) {
1654                 if (!revision)
1655                         s.mode = &patch_mode_checkout_index;
1656                 else if (!strcmp(revision, "HEAD"))
1657                         s.mode = &patch_mode_checkout_head;
1658                 else
1659                         s.mode = &patch_mode_checkout_nothead;
1660         } else if (mode == ADD_P_WORKTREE) {
1661                 if (!revision)
1662                         s.mode = &patch_mode_checkout_index;
1663                 else if (!strcmp(revision, "HEAD"))
1664                         s.mode = &patch_mode_worktree_head;
1665                 else
1666                         s.mode = &patch_mode_worktree_nothead;
1667         } else
1668                 s.mode = &patch_mode_add;
1669         s.revision = revision;
1670
1671         if (discard_index(r->index) < 0 || repo_read_index(r) < 0 ||
1672             (!s.mode->index_only &&
1673              repo_refresh_and_write_index(r, REFRESH_QUIET, 0, 1,
1674                                           NULL, NULL, NULL) < 0) ||
1675             parse_diff(&s, ps) < 0) {
1676                 strbuf_release(&s.plain);
1677                 strbuf_release(&s.colored);
1678                 clear_add_i_state(&s.s);
1679                 return -1;
1680         }
1681
1682         for (i = 0; i < s.file_diff_nr; i++)
1683                 if (s.file_diff[i].binary && !s.file_diff[i].hunk_nr)
1684                         binary_count++;
1685                 else if (patch_update_file(&s, s.file_diff + i))
1686                         break;
1687
1688         if (s.file_diff_nr == 0)
1689                 fprintf(stderr, _("No changes.\n"));
1690         else if (binary_count == s.file_diff_nr)
1691                 fprintf(stderr, _("Only binary files changed.\n"));
1692
1693         strbuf_release(&s.answer);
1694         strbuf_release(&s.buf);
1695         strbuf_release(&s.plain);
1696         strbuf_release(&s.colored);
1697         clear_add_i_state(&s.s);
1698         return 0;
1699 }