Sixth batch for 2.5 cycle
[git/git.git] / builtin / replace.c
CommitLineData
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1/*
2 * Builtin "git replace"
3 *
4 * Copyright (c) 2008 Christian Couder <chriscool@tuxfamily.org>
5 *
09b7e220 6 * Based on builtin/tag.c by Kristian Høgsberg <krh@redhat.com>
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7 * and Carlos Rica <jasampler@gmail.com> that was itself based on
8 * git-tag.sh and mktag.c by Linus Torvalds.
9 */
10
11#include "cache.h"
12#include "builtin.h"
13#include "refs.h"
14#include "parse-options.h"
b892bb45 15#include "run-command.h"
25a05a8c 16#include "tag.h"
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17
18static const char * const git_replace_usage[] = {
2477bebb 19 N_("git replace [-f] <object> <replacement>"),
ab77c309 20 N_("git replace [-f] --edit <object>"),
4228e8bc 21 N_("git replace [-f] --graft <commit> [<parent>...]"),
2477bebb 22 N_("git replace -d <object>..."),
44f9f850 23 N_("git replace [--format=<format>] [-l [<pattern>]]"),
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24 NULL
25};
26
663a8566 27enum replace_format {
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28 REPLACE_FORMAT_SHORT,
29 REPLACE_FORMAT_MEDIUM,
30 REPLACE_FORMAT_LONG
663a8566 31};
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32
33struct show_data {
34 const char *pattern;
663a8566 35 enum replace_format format;
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36};
37
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38static int show_reference(const char *refname, const unsigned char *sha1,
39 int flag, void *cb_data)
40{
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41 struct show_data *data = cb_data;
42
eb07894f 43 if (!wildmatch(data->pattern, refname, 0, NULL)) {
663a8566 44 if (data->format == REPLACE_FORMAT_SHORT)
44f9f850 45 printf("%s\n", refname);
663a8566 46 else if (data->format == REPLACE_FORMAT_MEDIUM)
44f9f850 47 printf("%s -> %s\n", refname, sha1_to_hex(sha1));
663a8566 48 else { /* data->format == REPLACE_FORMAT_LONG */
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49 unsigned char object[20];
50 enum object_type obj_type, repl_type;
54b0c1e0 51
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52 if (get_sha1(refname, object))
53 return error("Failed to resolve '%s' as a valid ref.", refname);
54
55 obj_type = sha1_object_info(object, NULL);
56 repl_type = sha1_object_info(sha1, NULL);
57
58 printf("%s (%s) -> %s (%s)\n", refname, typename(obj_type),
59 sha1_to_hex(sha1), typename(repl_type));
60 }
61 }
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62
63 return 0;
64}
65
44f9f850 66static int list_replace_refs(const char *pattern, const char *format)
54b0c1e0 67{
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68 struct show_data data;
69
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70 if (pattern == NULL)
71 pattern = "*";
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72 data.pattern = pattern;
73
74 if (format == NULL || *format == '\0' || !strcmp(format, "short"))
663a8566 75 data.format = REPLACE_FORMAT_SHORT;
44f9f850 76 else if (!strcmp(format, "medium"))
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77 data.format = REPLACE_FORMAT_MEDIUM;
78 else if (!strcmp(format, "long"))
79 data.format = REPLACE_FORMAT_LONG;
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80 else
81 die("invalid replace format '%s'\n"
663a8566 82 "valid formats are 'short', 'medium' and 'long'\n",
44f9f850 83 format);
54b0c1e0 84
44f9f850 85 for_each_replace_ref(show_reference, (void *) &data);
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86
87 return 0;
88}
89
90typedef int (*each_replace_name_fn)(const char *name, const char *ref,
91 const unsigned char *sha1);
92
93static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
94{
9dfc3684 95 const char **p, *full_hex;
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96 char ref[PATH_MAX];
97 int had_error = 0;
98 unsigned char sha1[20];
99
100 for (p = argv; *p; p++) {
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101 if (get_sha1(*p, sha1)) {
102 error("Failed to resolve '%s' as a valid ref.", *p);
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103 had_error = 1;
104 continue;
105 }
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106 full_hex = sha1_to_hex(sha1);
107 snprintf(ref, sizeof(ref), "refs/replace/%s", full_hex);
108 /* read_ref() may reuse the buffer */
109 full_hex = ref + strlen("refs/replace/");
c6893323 110 if (read_ref(ref, sha1)) {
9dfc3684 111 error("replace ref '%s' not found.", full_hex);
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112 had_error = 1;
113 continue;
114 }
9dfc3684 115 if (fn(full_hex, ref, sha1))
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116 had_error = 1;
117 }
118 return had_error;
119}
120
121static int delete_replace_ref(const char *name, const char *ref,
122 const unsigned char *sha1)
123{
124 if (delete_ref(ref, sha1, 0))
125 return 1;
126 printf("Deleted replace ref '%s'\n", name);
127 return 0;
128}
129
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130static void check_ref_valid(unsigned char object[20],
131 unsigned char prev[20],
132 char *ref,
133 int ref_size,
134 int force)
135{
136 if (snprintf(ref, ref_size,
137 "refs/replace/%s",
138 sha1_to_hex(object)) > ref_size - 1)
139 die("replace ref name too long: %.*s...", 50, ref);
140 if (check_refname_format(ref, 0))
141 die("'%s' is not a valid ref name.", ref);
142
143 if (read_ref(ref, prev))
144 hashclr(prev);
145 else if (!force)
146 die("replace ref '%s' already exists", ref);
147}
148
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149static int replace_object_sha1(const char *object_ref,
150 unsigned char object[20],
151 const char *replace_ref,
152 unsigned char repl[20],
153 int force)
bebdd271 154{
479bd757 155 unsigned char prev[20];
277336a5 156 enum object_type obj_type, repl_type;
bebdd271 157 char ref[PATH_MAX];
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158 struct ref_transaction *transaction;
159 struct strbuf err = STRBUF_INIT;
bebdd271 160
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161 obj_type = sha1_object_info(object, NULL);
162 repl_type = sha1_object_info(repl, NULL);
163 if (!force && obj_type != repl_type)
164 die("Objects must be of the same type.\n"
165 "'%s' points to a replaced object of type '%s'\n"
166 "while '%s' points to a replacement object of type '%s'.",
167 object_ref, typename(obj_type),
168 replace_ref, typename(repl_type));
169
b6e38840 170 check_ref_valid(object, prev, ref, sizeof(ref), force);
bebdd271 171
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172 transaction = ref_transaction_begin(&err);
173 if (!transaction ||
db7516ab 174 ref_transaction_update(transaction, ref, repl, prev,
1d147bdf 175 0, NULL, &err) ||
db7516ab 176 ref_transaction_commit(transaction, &err))
867c2fac 177 die("%s", err.buf);
bebdd271 178
867c2fac 179 ref_transaction_free(transaction);
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180 return 0;
181}
182
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183static int replace_object(const char *object_ref, const char *replace_ref, int force)
184{
185 unsigned char object[20], repl[20];
186
187 if (get_sha1(object_ref, object))
188 die("Failed to resolve '%s' as a valid ref.", object_ref);
189 if (get_sha1(replace_ref, repl))
190 die("Failed to resolve '%s' as a valid ref.", replace_ref);
191
192 return replace_object_sha1(object_ref, object, replace_ref, repl, force);
193}
194
b892bb45 195/*
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196 * Write the contents of the object named by "sha1" to the file "filename".
197 * If "raw" is true, then the object's raw contents are printed according to
198 * "type". Otherwise, we pretty-print the contents for human editing.
b892bb45 199 */
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200static void export_object(const unsigned char *sha1, enum object_type type,
201 int raw, const char *filename)
b892bb45 202{
d3180279 203 struct child_process cmd = CHILD_PROCESS_INIT;
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204 int fd;
205
206 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
207 if (fd < 0)
208 die_errno("unable to open %s for writing", filename);
209
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210 argv_array_push(&cmd.args, "--no-replace-objects");
211 argv_array_push(&cmd.args, "cat-file");
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212 if (raw)
213 argv_array_push(&cmd.args, typename(type));
214 else
215 argv_array_push(&cmd.args, "-p");
36857e00 216 argv_array_push(&cmd.args, sha1_to_hex(sha1));
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217 cmd.git_cmd = 1;
218 cmd.out = fd;
219
220 if (run_command(&cmd))
221 die("cat-file reported failure");
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222}
223
224/*
225 * Read a previously-exported (and possibly edited) object back from "filename",
226 * interpreting it as "type", and writing the result to the object database.
227 * The sha1 of the written object is returned via sha1.
228 */
229static void import_object(unsigned char *sha1, enum object_type type,
2deda629 230 int raw, const char *filename)
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231{
232 int fd;
233
234 fd = open(filename, O_RDONLY);
235 if (fd < 0)
236 die_errno("unable to open %s for reading", filename);
237
2deda629 238 if (!raw && type == OBJ_TREE) {
b892bb45 239 const char *argv[] = { "mktree", NULL };
d3180279 240 struct child_process cmd = CHILD_PROCESS_INIT;
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241 struct strbuf result = STRBUF_INIT;
242
243 cmd.argv = argv;
244 cmd.git_cmd = 1;
245 cmd.in = fd;
246 cmd.out = -1;
247
248 if (start_command(&cmd))
249 die("unable to spawn mktree");
250
251 if (strbuf_read(&result, cmd.out, 41) < 0)
252 die_errno("unable to read from mktree");
253 close(cmd.out);
254
255 if (finish_command(&cmd))
256 die("mktree reported failure");
257 if (get_sha1_hex(result.buf, sha1) < 0)
258 die("mktree did not return an object name");
259
260 strbuf_release(&result);
261 } else {
262 struct stat st;
263 int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
264
265 if (fstat(fd, &st) < 0)
266 die_errno("unable to fstat %s", filename);
267 if (index_fd(sha1, fd, &st, type, NULL, flags) < 0)
268 die("unable to write object to database");
269 /* index_fd close()s fd for us */
270 }
271
272 /*
273 * No need to close(fd) here; both run-command and index-fd
274 * will have done it for us.
275 */
276}
277
2deda629 278static int edit_and_replace(const char *object_ref, int force, int raw)
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279{
280 char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
281 enum object_type type;
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282 unsigned char old[20], new[20], prev[20];
283 char ref[PATH_MAX];
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284
285 if (get_sha1(object_ref, old) < 0)
286 die("Not a valid object name: '%s'", object_ref);
287
288 type = sha1_object_info(old, NULL);
289 if (type < 0)
290 die("unable to get object type for %s", sha1_to_hex(old));
291
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292 check_ref_valid(old, prev, ref, sizeof(ref), force);
293
2deda629 294 export_object(old, type, raw, tmpfile);
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295 if (launch_editor(tmpfile, NULL, NULL) < 0)
296 die("editing object file failed");
2deda629 297 import_object(new, type, raw, tmpfile);
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298
299 free(tmpfile);
300
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301 if (!hashcmp(old, new))
302 return error("new object is the same as the old one: '%s'", sha1_to_hex(old));
303
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304 return replace_object_sha1(object_ref, old, "replacement", new, force);
305}
306
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307static void replace_parents(struct strbuf *buf, int argc, const char **argv)
308{
309 struct strbuf new_parents = STRBUF_INIT;
310 const char *parent_start, *parent_end;
311 int i;
312
313 /* find existing parents */
314 parent_start = buf->buf;
315 parent_start += 46; /* "tree " + "hex sha1" + "\n" */
316 parent_end = parent_start;
317
318 while (starts_with(parent_end, "parent "))
319 parent_end += 48; /* "parent " + "hex sha1" + "\n" */
320
321 /* prepare new parents */
322 for (i = 0; i < argc; i++) {
323 unsigned char sha1[20];
324 if (get_sha1(argv[i], sha1) < 0)
325 die(_("Not a valid object name: '%s'"), argv[i]);
326 lookup_commit_or_die(sha1, argv[i]);
327 strbuf_addf(&new_parents, "parent %s\n", sha1_to_hex(sha1));
328 }
329
330 /* replace existing parents with new ones */
331 strbuf_splice(buf, parent_start - buf->buf, parent_end - parent_start,
332 new_parents.buf, new_parents.len);
333
334 strbuf_release(&new_parents);
335}
336
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337struct check_mergetag_data {
338 int argc;
339 const char **argv;
340};
341
342static void check_one_mergetag(struct commit *commit,
343 struct commit_extra_header *extra,
344 void *data)
345{
346 struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
347 const char *ref = mergetag_data->argv[0];
348 unsigned char tag_sha1[20];
349 struct tag *tag;
350 int i;
351
352 hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_sha1);
353 tag = lookup_tag(tag_sha1);
354 if (!tag)
355 die(_("bad mergetag in commit '%s'"), ref);
356 if (parse_tag_buffer(tag, extra->value, extra->len))
357 die(_("malformed mergetag in commit '%s'"), ref);
358
359 /* iterate over new parents */
360 for (i = 1; i < mergetag_data->argc; i++) {
361 unsigned char sha1[20];
362 if (get_sha1(mergetag_data->argv[i], sha1) < 0)
363 die(_("Not a valid object name: '%s'"), mergetag_data->argv[i]);
364 if (!hashcmp(tag->tagged->sha1, sha1))
365 return; /* found */
366 }
367
368 die(_("original commit '%s' contains mergetag '%s' that is discarded; "
369 "use --edit instead of --graft"), ref, sha1_to_hex(tag_sha1));
370}
371
372static void check_mergetags(struct commit *commit, int argc, const char **argv)
373{
374 struct check_mergetag_data mergetag_data;
375
376 mergetag_data.argc = argc;
377 mergetag_data.argv = argv;
378 for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
379}
380
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381static int create_graft(int argc, const char **argv, int force)
382{
383 unsigned char old[20], new[20];
384 const char *old_ref = argv[0];
385 struct commit *commit;
386 struct strbuf buf = STRBUF_INIT;
387 const char *buffer;
388 unsigned long size;
389
390 if (get_sha1(old_ref, old) < 0)
391 die(_("Not a valid object name: '%s'"), old_ref);
392 commit = lookup_commit_or_die(old, old_ref);
393
394 buffer = get_commit_buffer(commit, &size);
395 strbuf_add(&buf, buffer, size);
396 unuse_commit_buffer(commit, buffer);
397
398 replace_parents(&buf, argc - 1, &argv[1]);
399
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400 if (remove_signature(&buf)) {
401 warning(_("the original commit '%s' has a gpg signature."), old_ref);
402 warning(_("the signature will be removed in the replacement commit!"));
403 }
404
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405 check_mergetags(commit, argc, argv);
406
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407 if (write_sha1_file(buf.buf, buf.len, commit_type, new))
408 die(_("could not write replacement commit for: '%s'"), old_ref);
409
410 strbuf_release(&buf);
411
412 if (!hashcmp(old, new))
413 return error("new commit is the same as the old one: '%s'", sha1_to_hex(old));
414
415 return replace_object_sha1(old_ref, old, "replacement", new, force);
416}
417
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418int cmd_replace(int argc, const char **argv, const char *prefix)
419{
70c7bd6d 420 int force = 0;
2deda629 421 int raw = 0;
44f9f850 422 const char *format = NULL;
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423 enum {
424 MODE_UNSPECIFIED = 0,
425 MODE_LIST,
426 MODE_DELETE,
b892bb45 427 MODE_EDIT,
4228e8bc 428 MODE_GRAFT,
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429 MODE_REPLACE
430 } cmdmode = MODE_UNSPECIFIED;
54b0c1e0 431 struct option options[] = {
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432 OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
433 OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
b892bb45 434 OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
4228e8bc 435 OPT_CMDMODE('g', "graft", &cmdmode, N_("change a commit's parents"), MODE_GRAFT),
80f165a5 436 OPT_BOOL('f', "force", &force, N_("replace the ref if it exists")),
2deda629 437 OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
44f9f850 438 OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
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439 OPT_END()
440 };
441
afc711b8 442 check_replace_refs = 0;
769a4fa4 443
451bb210 444 argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
54b0c1e0 445
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446 if (!cmdmode)
447 cmdmode = argc ? MODE_REPLACE : MODE_LIST;
3f495f67 448
70c7bd6d 449 if (format && cmdmode != MODE_LIST)
3f495f67 450 usage_msg_opt("--format cannot be used when not listing",
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451 git_replace_usage, options);
452
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453 if (force &&
454 cmdmode != MODE_REPLACE &&
455 cmdmode != MODE_EDIT &&
456 cmdmode != MODE_GRAFT)
70c7bd6d 457 usage_msg_opt("-f only makes sense when writing a replacement",
86af2caa 458 git_replace_usage, options);
bebdd271 459
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460 if (raw && cmdmode != MODE_EDIT)
461 usage_msg_opt("--raw only makes sense with --edit",
462 git_replace_usage, options);
463
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464 switch (cmdmode) {
465 case MODE_DELETE:
54b0c1e0 466 if (argc < 1)
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467 usage_msg_opt("-d needs at least one argument",
468 git_replace_usage, options);
54b0c1e0 469 return for_each_replace_name(argv, delete_replace_ref);
54b0c1e0 470
70c7bd6d 471 case MODE_REPLACE:
bebdd271 472 if (argc != 2)
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473 usage_msg_opt("bad number of arguments",
474 git_replace_usage, options);
bebdd271 475 return replace_object(argv[0], argv[1], force);
bebdd271 476
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477 case MODE_EDIT:
478 if (argc != 1)
479 usage_msg_opt("-e needs exactly one argument",
480 git_replace_usage, options);
2deda629 481 return edit_and_replace(argv[0], force, raw);
b892bb45 482
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483 case MODE_GRAFT:
484 if (argc < 1)
485 usage_msg_opt("-g needs at least one argument",
486 git_replace_usage, options);
487 return create_graft(argc, argv, force);
488
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489 case MODE_LIST:
490 if (argc > 1)
491 usage_msg_opt("only one pattern can be given with -l",
492 git_replace_usage, options);
493 return list_replace_refs(argv[0], format);
54b0c1e0 494
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495 default:
496 die("BUG: invalid cmdmode %d", (int)cmdmode);
497 }
54b0c1e0 498}