git.oblomov.eu Git - git/blob - 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
  10 enum prompt_mode_type {
  11         PROMPT_MODE_CHANGE = 0, PROMPT_DELETION, PROMPT_HUNK
  12 };
  13
  14 static const char *prompt_mode[] = {
  15         N_("Stage mode change [y,n,a,d%s,?]? "),
  16         N_("Stage deletion [y,n,a,d%s,?]? "),
  17         N_("Stage this hunk [y,n,a,d%s,?]? ")
  18 };
  19
  20 struct hunk_header {
  21         unsigned long old_offset, old_count, new_offset, new_count;
  22         /*
  23          * Start/end offsets to the extra text after the second `@@` in the
  24          * hunk header, e.g. the function signature. This is expected to
  25          * include the newline.
  26          */
  27         size_t extra_start, extra_end, colored_extra_start, colored_extra_end;
  28 };
  29
  30 struct hunk {
  31         size_t start, end, colored_start, colored_end, splittable_into;
  32         enum { UNDECIDED_HUNK = 0, SKIP_HUNK, USE_HUNK } use;
  33         struct hunk_header header;
  34 };
  35
  36 struct add_p_state {
  37         struct add_i_state s;
  38         struct strbuf answer, buf;
  39
  40         /* parsed diff */
  41         struct strbuf plain, colored;
  42         struct file_diff {
  43                 struct hunk head;
  44                 struct hunk *hunk;
  45                 size_t hunk_nr, hunk_alloc;
  46                 unsigned deleted:1, mode_change:1;
  47         } *file_diff;
  48         size_t file_diff_nr;
  49 };
  50
  51 static void err(struct add_p_state *s, const char *fmt, ...)
  52 {
  53         va_list args;
  54
  55         va_start(args, fmt);
  56         fputs(s->s.error_color, stderr);
  57         vfprintf(stderr, fmt, args);
  58         fputs(s->s.reset_color, stderr);
  59         fputc('\n', stderr);
  60         va_end(args);
  61 }
  62
  63 static void setup_child_process(struct add_p_state *s,
  64                                 struct child_process *cp, ...)
  65 {
  66         va_list ap;
  67         const char *arg;
  68
  69         va_start(ap, cp);
  70         while ((arg = va_arg(ap, const char *)))
  71                 argv_array_push(&cp->args, arg);
  72         va_end(ap);
  73
  74         cp->git_cmd = 1;
  75         argv_array_pushf(&cp->env_array,
  76                          INDEX_ENVIRONMENT "=%s", s->s.r->index_file);
  77 }
  78
  79 static int parse_range(const char **p,
  80                        unsigned long *offset, unsigned long *count)
  81 {
  82         char *pend;
  83
  84         *offset = strtoul(*p, &pend, 10);
  85         if (pend == *p)
  86                 return -1;
  87         if (*pend != ',') {
  88                 *count = 1;
  89                 *p = pend;
  90                 return 0;
  91         }
  92         *count = strtoul(pend + 1, (char **)p, 10);
  93         return *p == pend + 1 ? -1 : 0;
  94 }
  95
  96 static int parse_hunk_header(struct add_p_state *s, struct hunk *hunk)
  97 {
  98         struct hunk_header *header = &hunk->header;
  99         const char *line = s->plain.buf + hunk->start, *p = line;
 100         char *eol = memchr(p, '\n', s->plain.len - hunk->start);
 101
 102         if (!eol)
 103                 eol = s->plain.buf + s->plain.len;
 104
 105         if (!skip_prefix(p, "@@ -", &p) ||
 106             parse_range(&p, &header->old_offset, &header->old_count) < 0 ||
 107             !skip_prefix(p, " +", &p) ||
 108             parse_range(&p, &header->new_offset, &header->new_count) < 0 ||
 109             !skip_prefix(p, " @@", &p))
 110                 return error(_("could not parse hunk header '%.*s'"),
 111                              (int)(eol - line), line);
 112
 113         hunk->start = eol - s->plain.buf + (*eol == '\n');
 114         header->extra_start = p - s->plain.buf;
 115         header->extra_end = hunk->start;
 116
 117         if (!s->colored.len) {
 118                 header->colored_extra_start = header->colored_extra_end = 0;
 119                 return 0;
 120         }
 121
 122         /* Now find the extra text in the colored diff */
 123         line = s->colored.buf + hunk->colored_start;
 124         eol = memchr(line, '\n', s->colored.len - hunk->colored_start);
 125         if (!eol)
 126                 eol = s->colored.buf + s->colored.len;
 127         p = memmem(line, eol - line, "@@ -", 4);
 128         if (!p)
 129                 return error(_("could not parse colored hunk header '%.*s'"),
 130                              (int)(eol - line), line);
 131         p = memmem(p + 4, eol - p - 4, " @@", 3);
 132         if (!p)
 133                 return error(_("could not parse colored hunk header '%.*s'"),
 134                              (int)(eol - line), line);
 135         hunk->colored_start = eol - s->colored.buf + (*eol == '\n');
 136         header->colored_extra_start = p + 3 - s->colored.buf;
 137         header->colored_extra_end = hunk->colored_start;
 138
 139         return 0;
 140 }
 141
 142 static int is_octal(const char *p, size_t len)
 143 {
 144         if (!len)
 145                 return 0;
 146
 147         while (len--)
 148                 if (*p < '0' || *(p++) > '7')
 149                         return 0;
 150         return 1;
 151 }
 152
 153 static int parse_diff(struct add_p_state *s, const struct pathspec *ps)
 154 {
 155         struct argv_array args = ARGV_ARRAY_INIT;
 156         struct strbuf *plain = &s->plain, *colored = NULL;
 157         struct child_process cp = CHILD_PROCESS_INIT;
 158         char *p, *pend, *colored_p = NULL, *colored_pend = NULL, marker = '\0';
 159         size_t file_diff_alloc = 0, i, color_arg_index;
 160         struct file_diff *file_diff = NULL;
 161         struct hunk *hunk = NULL;
 162         int res;
 163
 164         /* Use `--no-color` explicitly, just in case `diff.color = always`. */
 165         argv_array_pushl(&args, "diff-files", "-p", "--no-color", "--", NULL);
 166         color_arg_index = args.argc - 2;
 167         for (i = 0; i < ps->nr; i++)
 168                 argv_array_push(&args, ps->items[i].original);
 169
 170         setup_child_process(s, &cp, NULL);
 171         cp.argv = args.argv;
 172         res = capture_command(&cp, plain, 0);
 173         if (res) {
 174                 argv_array_clear(&args);
 175                 return error(_("could not parse diff"));
 176         }
 177         if (!plain->len) {
 178                 argv_array_clear(&args);
 179                 return 0;
 180         }
 181         strbuf_complete_line(plain);
 182
 183         if (want_color_fd(1, -1)) {
 184                 struct child_process colored_cp = CHILD_PROCESS_INIT;
 185
 186                 setup_child_process(s, &colored_cp, NULL);
 187                 xsnprintf((char *)args.argv[color_arg_index], 8, "--color");
 188                 colored_cp.argv = args.argv;
 189                 colored = &s->colored;
 190                 res = capture_command(&colored_cp, colored, 0);
 191                 argv_array_clear(&args);
 192                 if (res)
 193                         return error(_("could not parse colored diff"));
 194                 strbuf_complete_line(colored);
 195                 colored_p = colored->buf;
 196                 colored_pend = colored_p + colored->len;
 197         }
 198         argv_array_clear(&args);
 199
 200         /* parse files and hunks */
 201         p = plain->buf;
 202         pend = p + plain->len;
 203         while (p != pend) {
 204                 char *eol = memchr(p, '\n', pend - p);
 205                 const char *deleted = NULL, *mode_change = NULL;
 206
 207                 if (!eol)
 208                         eol = pend;
 209
 210                 if (starts_with(p, "diff ")) {
 211                         s->file_diff_nr++;
 212                         ALLOC_GROW(s->file_diff, s->file_diff_nr,
 213                                    file_diff_alloc);
 214                         file_diff = s->file_diff + s->file_diff_nr - 1;
 215                         memset(file_diff, 0, sizeof(*file_diff));
 216                         hunk = &file_diff->head;
 217                         hunk->start = p - plain->buf;
 218                         if (colored_p)
 219                                 hunk->colored_start = colored_p - colored->buf;
 220                         marker = '\0';
 221                 } else if (p == plain->buf)
 222                         BUG("diff starts with unexpected line:\n"
 223                             "%.*s\n", (int)(eol - p), p);
 224                 else if (file_diff->deleted)
 225                         ; /* keep the rest of the file in a single "hunk" */
 226                 else if (starts_with(p, "@@ ") ||
 227                          (hunk == &file_diff->head &&
 228                           skip_prefix(p, "deleted file", &deleted))) {
 229                         if (marker == '-' || marker == '+')
 230                                 /*
 231                                  * Should not happen; previous hunk did not end
 232                                  * in a context line? Handle it anyway.
 233                                  */
 234                                 hunk->splittable_into++;
 235
 236                         file_diff->hunk_nr++;
 237                         ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr,
 238                                    file_diff->hunk_alloc);
 239                         hunk = file_diff->hunk + file_diff->hunk_nr - 1;
 240                         memset(hunk, 0, sizeof(*hunk));
 241
 242                         hunk->start = p - plain->buf;
 243                         if (colored)
 244                                 hunk->colored_start = colored_p - colored->buf;
 245
 246                         if (deleted)
 247                                 file_diff->deleted = 1;
 248                         else if (parse_hunk_header(s, hunk) < 0)
 249                                 return -1;
 250
 251                         /*
 252                          * Start counting into how many hunks this one can be
 253                          * split
 254                          */
 255                         marker = *p;
 256                 } else if (hunk == &file_diff->head &&
 257                            skip_prefix(p, "old mode ", &mode_change) &&
 258                            is_octal(mode_change, eol - mode_change)) {
 259                         if (file_diff->mode_change)
 260                                 BUG("double mode change?\n\n%.*s",
 261                                     (int)(eol - plain->buf), plain->buf);
 262                         if (file_diff->hunk_nr++)
 263                                 BUG("mode change in the middle?\n\n%.*s",
 264                                     (int)(eol - plain->buf), plain->buf);
 265
 266                         /*
 267                          * Do *not* change `hunk`: the mode change pseudo-hunk
 268                          * is _part of_ the header "hunk".
 269                          */
 270                         file_diff->mode_change = 1;
 271                         ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr,
 272                                    file_diff->hunk_alloc);
 273                         memset(file_diff->hunk, 0, sizeof(struct hunk));
 274                         file_diff->hunk->start = p - plain->buf;
 275                         if (colored_p)
 276                                 file_diff->hunk->colored_start =
 277                                         colored_p - colored->buf;
 278                 } else if (hunk == &file_diff->head &&
 279                            skip_prefix(p, "new mode ", &mode_change) &&
 280                            is_octal(mode_change, eol - mode_change)) {
 281
 282                         /*
 283                          * Extend the "mode change" pseudo-hunk to include also
 284                          * the "new mode" line.
 285                          */
 286                         if (!file_diff->mode_change)
 287                                 BUG("'new mode' without 'old mode'?\n\n%.*s",
 288                                     (int)(eol - plain->buf), plain->buf);
 289                         if (file_diff->hunk_nr != 1)
 290                                 BUG("mode change in the middle?\n\n%.*s",
 291                                     (int)(eol - plain->buf), plain->buf);
 292                         if (p - plain->buf != file_diff->hunk->end)
 293                                 BUG("'new mode' does not immediately follow "
 294                                     "'old mode'?\n\n%.*s",
 295                                     (int)(eol - plain->buf), plain->buf);
 296                 }
 297
 298                 if (file_diff->deleted && file_diff->mode_change)
 299                         BUG("diff contains delete *and* a mode change?!?\n%.*s",
 300                             (int)(eol - (plain->buf + file_diff->head.start)),
 301                             plain->buf + file_diff->head.start);
 302
 303                 if ((marker == '-' || marker == '+') && *p == ' ')
 304                         hunk->splittable_into++;
 305                 if (marker && *p != '\\')
 306                         marker = *p;
 307
 308                 p = eol == pend ? pend : eol + 1;
 309                 hunk->end = p - plain->buf;
 310
 311                 if (colored) {
 312                         char *colored_eol = memchr(colored_p, '\n',
 313                                                    colored_pend - colored_p);
 314                         if (colored_eol)
 315                                 colored_p = colored_eol + 1;
 316                         else
 317                                 colored_p = colored_pend;
 318
 319                         hunk->colored_end = colored_p - colored->buf;
 320                 }
 321
 322                 if (mode_change) {
 323                         if (file_diff->hunk_nr != 1)
 324                                 BUG("mode change in hunk #%d???",
 325                                     (int)file_diff->hunk_nr);
 326                         /* Adjust the end of the "mode change" pseudo-hunk */
 327                         file_diff->hunk->end = hunk->end;
 328                         if (colored)
 329                                 file_diff->hunk->colored_end = hunk->colored_end;
 330                 }
 331         }
 332
 333         if (marker == '-' || marker == '+')
 334                 /*
 335                  * Last hunk ended in non-context line (i.e. it appended lines
 336                  * to the file, so there are no trailing context lines).
 337                  */
 338                 hunk->splittable_into++;
 339
 340         return 0;
 341 }
 342
 343 static size_t find_next_line(struct strbuf *sb, size_t offset)
 344 {
 345         char *eol;
 346
 347         if (offset >= sb->len)
 348                 BUG("looking for next line beyond buffer (%d >= %d)\n%s",
 349                     (int)offset, (int)sb->len, sb->buf);
 350
 351         eol = memchr(sb->buf + offset, '\n', sb->len - offset);
 352         if (!eol)
 353                 return sb->len;
 354         return eol - sb->buf + 1;
 355 }
 356
 357 static void render_hunk(struct add_p_state *s, struct hunk *hunk,
 358                         ssize_t delta, int colored, struct strbuf *out)
 359 {
 360         struct hunk_header *header = &hunk->header;
 361
 362         if (hunk->header.old_offset != 0 || hunk->header.new_offset != 0) {
 363                 /*
 364                  * Generate the hunk header dynamically, except for special
 365                  * hunks (such as the diff header).
 366                  */
 367                 const char *p;
 368                 size_t len;
 369                 unsigned long old_offset = header->old_offset;
 370                 unsigned long new_offset = header->new_offset;
 371
 372                 if (!colored) {
 373                         p = s->plain.buf + header->extra_start;
 374                         len = header->extra_end - header->extra_start;
 375                 } else {
 376                         strbuf_addstr(out, s->s.fraginfo_color);
 377                         p = s->colored.buf + header->colored_extra_start;
 378                         len = header->colored_extra_end
 379                                 - header->colored_extra_start;
 380                 }
 381
 382                 new_offset += delta;
 383
 384                 strbuf_addf(out, "@@ -%lu,%lu +%lu,%lu @@",
 385                             old_offset, header->old_count,
 386                             new_offset, header->new_count);
 387                 if (len)
 388                         strbuf_add(out, p, len);
 389                 else if (colored)
 390                         strbuf_addf(out, "%s\n", GIT_COLOR_RESET);
 391                 else
 392                         strbuf_addch(out, '\n');
 393         }
 394
 395         if (colored)
 396                 strbuf_add(out, s->colored.buf + hunk->colored_start,
 397                            hunk->colored_end - hunk->colored_start);
 398         else
 399                 strbuf_add(out, s->plain.buf + hunk->start,
 400                            hunk->end - hunk->start);
 401 }
 402
 403 static void render_diff_header(struct add_p_state *s,
 404                                struct file_diff *file_diff, int colored,
 405                                struct strbuf *out)
 406 {
 407         /*
 408          * If there was a mode change, the first hunk is a pseudo hunk that
 409          * corresponds to the mode line in the header. If the user did not want
 410          * to stage that "hunk", we actually have to cut it out from the header.
 411          */
 412         int skip_mode_change =
 413                 file_diff->mode_change && file_diff->hunk->use != USE_HUNK;
 414         struct hunk *head = &file_diff->head, *first = file_diff->hunk;
 415
 416         if (!skip_mode_change) {
 417                 render_hunk(s, head, 0, colored, out);
 418                 return;
 419         }
 420
 421         if (colored) {
 422                 const char *p = s->colored.buf;
 423
 424                 strbuf_add(out, p + head->colored_start,
 425                             first->colored_start - head->colored_start);
 426                 strbuf_add(out, p + first->colored_end,
 427                             head->colored_end - first->colored_end);
 428         } else {
 429                 const char *p = s->plain.buf;
 430
 431                 strbuf_add(out, p + head->start, first->start - head->start);
 432                 strbuf_add(out, p + first->end, head->end - first->end);
 433         }
 434 }
 435
 436 /* Coalesce hunks again that were split */
 437 static int merge_hunks(struct add_p_state *s, struct file_diff *file_diff,
 438                        size_t *hunk_index, struct hunk *merged)
 439 {
 440         size_t i = *hunk_index;
 441         struct hunk *hunk = file_diff->hunk + i;
 442         /* `header` corresponds to the merged hunk */
 443         struct hunk_header *header = &merged->header, *next;
 444
 445         if (hunk->use != USE_HUNK)
 446                 return 0;
 447
 448         *merged = *hunk;
 449         /* We simply skip the colored part (if any) when merging hunks */
 450         merged->colored_start = merged->colored_end = 0;
 451
 452         for (; i + 1 < file_diff->hunk_nr; i++) {
 453                 hunk++;
 454                 next = &hunk->header;
 455
 456                 /*
 457                  * Stop merging hunks when:
 458                  *
 459                  * - the hunk is not selected for use, or
 460                  * - the hunk does not overlap with the already-merged hunk(s)
 461                  */
 462                 if (hunk->use != USE_HUNK ||
 463                     header->new_offset >= next->new_offset ||
 464                     header->new_offset + header->new_count < next->new_offset ||
 465                     merged->start >= hunk->start ||
 466                     merged->end < hunk->start)
 467                         break;
 468
 469                 merged->end = hunk->end;
 470                 merged->colored_end = hunk->colored_end;
 471
 472                 header->old_count = next->old_offset + next->old_count
 473                         - header->old_offset;
 474                 header->new_count = next->new_offset + next->new_count
 475                         - header->new_offset;
 476         }
 477
 478         if (i == *hunk_index)
 479                 return 0;
 480
 481         *hunk_index = i;
 482         return 1;
 483 }
 484
 485 static void reassemble_patch(struct add_p_state *s,
 486                              struct file_diff *file_diff, struct strbuf *out)
 487 {
 488         struct hunk *hunk;
 489         size_t i;
 490         ssize_t delta = 0;
 491
 492         render_diff_header(s, file_diff, 0, out);
 493
 494         for (i = file_diff->mode_change; i < file_diff->hunk_nr; i++) {
 495                 struct hunk merged = { 0 };
 496
 497                 hunk = file_diff->hunk + i;
 498                 if (hunk->use != USE_HUNK)
 499                         delta += hunk->header.old_count
 500                                 - hunk->header.new_count;
 501                 else {
 502                         /* merge overlapping hunks into a temporary hunk */
 503                         if (merge_hunks(s, file_diff, &i, &merged))
 504                                 hunk = &merged;
 505
 506                         render_hunk(s, hunk, delta, 0, out);
 507                 }
 508         }
 509 }
 510
 511 static int split_hunk(struct add_p_state *s, struct file_diff *file_diff,
 512                        size_t hunk_index)
 513 {
 514         int colored = !!s->colored.len, first = 1;
 515         struct hunk *hunk = file_diff->hunk + hunk_index;
 516         size_t splittable_into;
 517         size_t end, colored_end, current, colored_current = 0, context_line_count;
 518         struct hunk_header remaining, *header;
 519         char marker, ch;
 520
 521         if (hunk_index >= file_diff->hunk_nr)
 522                 BUG("invalid hunk index: %d (must be >= 0 and < %d)",
 523                     (int)hunk_index, (int)file_diff->hunk_nr);
 524
 525         if (hunk->splittable_into < 2)
 526                 return 0;
 527         splittable_into = hunk->splittable_into;
 528
 529         end = hunk->end;
 530         colored_end = hunk->colored_end;
 531
 532         remaining = hunk->header;
 533
 534         file_diff->hunk_nr += splittable_into - 1;
 535         ALLOC_GROW(file_diff->hunk, file_diff->hunk_nr, file_diff->hunk_alloc);
 536         if (hunk_index + splittable_into < file_diff->hunk_nr)
 537                 memmove(file_diff->hunk + hunk_index + splittable_into,
 538                         file_diff->hunk + hunk_index + 1,
 539                         (file_diff->hunk_nr - hunk_index - splittable_into)
 540                         * sizeof(*hunk));
 541         hunk = file_diff->hunk + hunk_index;
 542         hunk->splittable_into = 1;
 543         memset(hunk + 1, 0, (splittable_into - 1) * sizeof(*hunk));
 544
 545         header = &hunk->header;
 546         header->old_count = header->new_count = 0;
 547
 548         current = hunk->start;
 549         if (colored)
 550                 colored_current = hunk->colored_start;
 551         marker = '\0';
 552         context_line_count = 0;
 553
 554         while (splittable_into > 1) {
 555                 ch = s->plain.buf[current];
 556
 557                 if (!ch)
 558                         BUG("buffer overrun while splitting hunks");
 559
 560                 /*
 561                  * Is this the first context line after a chain of +/- lines?
 562                  * Then record the start of the next split hunk.
 563                  */
 564                 if ((marker == '-' || marker == '+') && ch == ' ') {
 565                         first = 0;
 566                         hunk[1].start = current;
 567                         if (colored)
 568                                 hunk[1].colored_start = colored_current;
 569                         context_line_count = 0;
 570                 }
 571
 572                 /*
 573                  * Was the previous line a +/- one? Alternatively, is this the
 574                  * first line (and not a +/- one)?
 575                  *
 576                  * Then just increment the appropriate counter and continue
 577                  * with the next line.
 578                  */
 579                 if (marker != ' ' || (ch != '-' && ch != '+')) {
 580 next_hunk_line:
 581                         /* Comment lines are attached to the previous line */
 582                         if (ch == '\\')
 583                                 ch = marker ? marker : ' ';
 584
 585                         /* current hunk not done yet */
 586                         if (ch == ' ')
 587                                 context_line_count++;
 588                         else if (ch == '-')
 589                                 header->old_count++;
 590                         else if (ch == '+')
 591                                 header->new_count++;
 592                         else
 593                                 BUG("unhandled diff marker: '%c'", ch);
 594                         marker = ch;
 595                         current = find_next_line(&s->plain, current);
 596                         if (colored)
 597                                 colored_current =
 598                                         find_next_line(&s->colored,
 599                                                        colored_current);
 600                         continue;
 601                 }
 602
 603                 /*
 604                  * We got us the start of a new hunk!
 605                  *
 606                  * This is a context line, so it is shared with the previous
 607                  * hunk, if any.
 608                  */
 609
 610                 if (first) {
 611                         if (header->old_count || header->new_count)
 612                                 BUG("counts are off: %d/%d",
 613                                     (int)header->old_count,
 614                                     (int)header->new_count);
 615
 616                         header->old_count = context_line_count;
 617                         header->new_count = context_line_count;
 618                         context_line_count = 0;
 619                         first = 0;
 620                         goto next_hunk_line;
 621                 }
 622
 623                 remaining.old_offset += header->old_count;
 624                 remaining.old_count -= header->old_count;
 625                 remaining.new_offset += header->new_count;
 626                 remaining.new_count -= header->new_count;
 627
 628                 /* initialize next hunk header's offsets */
 629                 hunk[1].header.old_offset =
 630                         header->old_offset + header->old_count;
 631                 hunk[1].header.new_offset =
 632                         header->new_offset + header->new_count;
 633
 634                 /* add one split hunk */
 635                 header->old_count += context_line_count;
 636                 header->new_count += context_line_count;
 637
 638                 hunk->end = current;
 639                 if (colored)
 640                         hunk->colored_end = colored_current;
 641
 642                 hunk++;
 643                 hunk->splittable_into = 1;
 644                 hunk->use = hunk[-1].use;
 645                 header = &hunk->header;
 646
 647                 header->old_count = header->new_count = context_line_count;
 648                 context_line_count = 0;
 649
 650                 splittable_into--;
 651                 marker = ch;
 652         }
 653
 654         /* last hunk simply gets the rest */
 655         if (header->old_offset != remaining.old_offset)
 656                 BUG("miscounted old_offset: %lu != %lu",
 657                     header->old_offset, remaining.old_offset);
 658         if (header->new_offset != remaining.new_offset)
 659                 BUG("miscounted new_offset: %lu != %lu",
 660                     header->new_offset, remaining.new_offset);
 661         header->old_count = remaining.old_count;
 662         header->new_count = remaining.new_count;
 663         hunk->end = end;
 664         if (colored)
 665                 hunk->colored_end = colored_end;
 666
 667         return 0;
 668 }
 669
 670 static const char help_patch_text[] =
 671 N_("y - stage this hunk\n"
 672    "n - do not stage this hunk\n"
 673    "a - stage this and all the remaining hunks\n"
 674    "d - do not stage this hunk nor any of the remaining hunks\n"
 675    "j - leave this hunk undecided, see next undecided hunk\n"
 676    "J - leave this hunk undecided, see next hunk\n"
 677    "k - leave this hunk undecided, see previous undecided hunk\n"
 678    "K - leave this hunk undecided, see previous hunk\n"
 679    "s - split the current hunk into smaller hunks\n"
 680    "? - print help\n");
 681
 682 static int patch_update_file(struct add_p_state *s,
 683                              struct file_diff *file_diff)
 684 {
 685         size_t hunk_index = 0;
 686         ssize_t i, undecided_previous, undecided_next;
 687         struct hunk *hunk;
 688         char ch;
 689         struct child_process cp = CHILD_PROCESS_INIT;
 690         int colored = !!s->colored.len;
 691         enum prompt_mode_type prompt_mode_type;
 692
 693         if (!file_diff->hunk_nr)
 694                 return 0;
 695
 696         strbuf_reset(&s->buf);
 697         render_diff_header(s, file_diff, colored, &s->buf);
 698         fputs(s->buf.buf, stdout);
 699         for (;;) {
 700                 if (hunk_index >= file_diff->hunk_nr)
 701                         hunk_index = 0;
 702                 hunk = file_diff->hunk + hunk_index;
 703
 704                 undecided_previous = -1;
 705                 for (i = hunk_index - 1; i >= 0; i--)
 706                         if (file_diff->hunk[i].use == UNDECIDED_HUNK) {
 707                                 undecided_previous = i;
 708                                 break;
 709                         }
 710
 711                 undecided_next = -1;
 712                 for (i = hunk_index + 1; i < file_diff->hunk_nr; i++)
 713                         if (file_diff->hunk[i].use == UNDECIDED_HUNK) {
 714                                 undecided_next = i;
 715                                 break;
 716                         }
 717
 718                 /* Everything decided? */
 719                 if (undecided_previous < 0 && undecided_next < 0 &&
 720                     hunk->use != UNDECIDED_HUNK)
 721                         break;
 722
 723                 strbuf_reset(&s->buf);
 724                 render_hunk(s, hunk, 0, colored, &s->buf);
 725                 fputs(s->buf.buf, stdout);
 726
 727                 strbuf_reset(&s->buf);
 728                 if (undecided_previous >= 0)
 729                         strbuf_addstr(&s->buf, ",k");
 730                 if (hunk_index)
 731                         strbuf_addstr(&s->buf, ",K");
 732                 if (undecided_next >= 0)
 733                         strbuf_addstr(&s->buf, ",j");
 734                 if (hunk_index + 1 < file_diff->hunk_nr)
 735                         strbuf_addstr(&s->buf, ",J");
 736                 if (hunk->splittable_into > 1)
 737                         strbuf_addstr(&s->buf, ",s");
 738
 739                 if (file_diff->deleted)
 740                         prompt_mode_type = PROMPT_DELETION;
 741                 else if (file_diff->mode_change && !hunk_index)
 742                         prompt_mode_type = PROMPT_MODE_CHANGE;
 743                 else
 744                         prompt_mode_type = PROMPT_HUNK;
 745
 746                 color_fprintf(stdout, s->s.prompt_color,
 747                               "(%"PRIuMAX"/%"PRIuMAX") ",
 748                               (uintmax_t)hunk_index + 1,
 749                               (uintmax_t)file_diff->hunk_nr);
 750                 color_fprintf(stdout, s->s.prompt_color,
 751                               _(prompt_mode[prompt_mode_type]), s->buf.buf);
 752                 fflush(stdout);
 753                 if (strbuf_getline(&s->answer, stdin) == EOF)
 754                         break;
 755                 strbuf_trim_trailing_newline(&s->answer);
 756
 757                 if (!s->answer.len)
 758                         continue;
 759                 ch = tolower(s->answer.buf[0]);
 760                 if (ch == 'y') {
 761                         hunk->use = USE_HUNK;
 762 soft_increment:
 763                         hunk_index = undecided_next < 0 ?
 764                                 file_diff->hunk_nr : undecided_next;
 765                 } else if (ch == 'n') {
 766                         hunk->use = SKIP_HUNK;
 767                         goto soft_increment;
 768                 } else if (ch == 'a') {
 769                         for (; hunk_index < file_diff->hunk_nr; hunk_index++) {
 770                                 hunk = file_diff->hunk + hunk_index;
 771                                 if (hunk->use == UNDECIDED_HUNK)
 772                                         hunk->use = USE_HUNK;
 773                         }
 774                 } else if (ch == 'd') {
 775                         for (; hunk_index < file_diff->hunk_nr; hunk_index++) {
 776                                 hunk = file_diff->hunk + hunk_index;
 777                                 if (hunk->use == UNDECIDED_HUNK)
 778                                         hunk->use = SKIP_HUNK;
 779                         }
 780                 } else if (s->answer.buf[0] == 'K') {
 781                         if (hunk_index)
 782                                 hunk_index--;
 783                         else
 784                                 err(s, _("No previous hunk"));
 785                 } else if (s->answer.buf[0] == 'J') {
 786                         if (hunk_index + 1 < file_diff->hunk_nr)
 787                                 hunk_index++;
 788                         else
 789                                 err(s, _("No next hunk"));
 790                 } else if (s->answer.buf[0] == 'k') {
 791                         if (undecided_previous >= 0)
 792                                 hunk_index = undecided_previous;
 793                         else
 794                                 err(s, _("No previous hunk"));
 795                 } else if (s->answer.buf[0] == 'j') {
 796                         if (undecided_next >= 0)
 797                                 hunk_index = undecided_next;
 798                         else
 799                                 err(s, _("No next hunk"));
 800                 } else if (s->answer.buf[0] == 's') {
 801                         size_t splittable_into = hunk->splittable_into;
 802                         if (splittable_into < 2)
 803                                 err(s, _("Sorry, cannot split this hunk"));
 804                         else if (!split_hunk(s, file_diff,
 805                                              hunk - file_diff->hunk))
 806                                 color_fprintf_ln(stdout, s->s.header_color,
 807                                                  _("Split into %d hunks."),
 808                                                  (int)splittable_into);
 809                 } else
 810                         color_fprintf(stdout, s->s.help_color,
 811                                       _(help_patch_text));
 812         }
 813
 814         /* Any hunk to be used? */
 815         for (i = 0; i < file_diff->hunk_nr; i++)
 816                 if (file_diff->hunk[i].use == USE_HUNK)
 817                         break;
 818
 819         if (i < file_diff->hunk_nr) {
 820                 /* At least one hunk selected: apply */
 821                 strbuf_reset(&s->buf);
 822                 reassemble_patch(s, file_diff, &s->buf);
 823
 824                 discard_index(s->s.r->index);
 825                 setup_child_process(s, &cp, "apply", "--cached", NULL);
 826                 if (pipe_command(&cp, s->buf.buf, s->buf.len,
 827                                  NULL, 0, NULL, 0))
 828                         error(_("'git apply --cached' failed"));
 829                 if (!repo_read_index(s->s.r))
 830                         repo_refresh_and_write_index(s->s.r, REFRESH_QUIET, 0,
 831                                                      1, NULL, NULL, NULL);
 832         }
 833
 834         putchar('\n');
 835         return 0;
 836 }
 837
 838 int run_add_p(struct repository *r, const struct pathspec *ps)
 839 {
 840         struct add_p_state s = {
 841                 { r }, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
 842         };
 843         size_t i;
 844
 845         init_add_i_state(&s.s, r);
 846
 847         if (discard_index(r->index) < 0 || repo_read_index(r) < 0 ||
 848             repo_refresh_and_write_index(r, REFRESH_QUIET, 0, 1,
 849                                          NULL, NULL, NULL) < 0 ||
 850             parse_diff(&s, ps) < 0) {
 851                 strbuf_release(&s.plain);
 852                 strbuf_release(&s.colored);
 853                 return -1;
 854         }
 855
 856         for (i = 0; i < s.file_diff_nr; i++)
 857                 if (patch_update_file(&s, s.file_diff + i))
 858                         break;
 859
 860         strbuf_release(&s.answer);
 861         strbuf_release(&s.buf);
 862         strbuf_release(&s.plain);
 863         strbuf_release(&s.colored);
 864         return 0;
 865 }