git-svn: make rebuild respect rewriteRoot option
[git/git.git] / builtin-reset.c
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1/*
2 * "git reset" builtin command
3 *
4 * Copyright (c) 2007 Carlos Rica
5 *
6 * Based on git-reset.sh, which is
7 *
8 * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
9 */
10#include "cache.h"
11#include "tag.h"
12#include "object.h"
13#include "commit.h"
14#include "run-command.h"
15#include "refs.h"
16#include "diff.h"
17#include "diffcore.h"
18#include "tree.h"
c369e7b8 19#include "branch.h"
5eee6b28 20#include "parse-options.h"
0e5a7faa 21
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22static const char * const git_reset_usage[] = {
23 "git-reset [--mixed | --soft | --hard] [-q] [<commit>]",
24 "git-reset [--mixed] <commit> [--] <paths>...",
25 NULL
26};
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27
28static char *args_to_str(const char **argv)
29{
30 char *buf = NULL;
31 unsigned long len, space = 0, nr = 0;
32
33 for (; *argv; argv++) {
34 len = strlen(*argv);
35 ALLOC_GROW(buf, nr + 1 + len, space);
36 if (nr)
37 buf[nr++] = ' ';
38 memcpy(buf + nr, *argv, len);
39 nr += len;
40 }
41 ALLOC_GROW(buf, nr + 1, space);
42 buf[nr] = '\0';
43
44 return buf;
45}
46
47static inline int is_merge(void)
48{
49 return !access(git_path("MERGE_HEAD"), F_OK);
50}
51
5aa965a0 52static int reset_index_file(const unsigned char *sha1, int is_hard_reset, int quiet)
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53{
54 int i = 0;
55 const char *args[6];
56
57 args[i++] = "read-tree";
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58 if (!quiet)
59 args[i++] = "-v";
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60 args[i++] = "--reset";
61 if (is_hard_reset)
62 args[i++] = "-u";
63 args[i++] = sha1_to_hex(sha1);
64 args[i] = NULL;
65
66 return run_command_v_opt(args, RUN_GIT_CMD);
67}
68
69static void print_new_head_line(struct commit *commit)
70{
2efb3b06 71 const char *hex, *body;
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72
73 hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
2efb3b06 74 printf("HEAD is now at %s", hex);
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75 body = strstr(commit->buffer, "\n\n");
76 if (body) {
77 const char *eol;
78 size_t len;
79 body += 2;
80 eol = strchr(body, '\n');
81 len = eol ? eol - body : strlen(body);
82 printf(" %.*s\n", (int) len, body);
83 }
84 else
85 printf("\n");
86}
87
620a6cd4 88static int update_index_refresh(int fd, struct lock_file *index_lock)
0e5a7faa 89{
620a6cd4 90 int result;
0e5a7faa 91
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92 if (!index_lock) {
93 index_lock = xcalloc(1, sizeof(struct lock_file));
94 fd = hold_locked_index(index_lock, 1);
95 }
0e5a7faa 96
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97 if (read_cache() < 0)
98 return error("Could not read index");
99 result = refresh_cache(0) ? 1 : 0;
100 if (write_cache(fd, active_cache, active_nr) ||
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101 commit_locked_index(index_lock))
102 return error ("Could not refresh index");
103 return result;
104}
2e7a9785 105
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106static void update_index_from_diff(struct diff_queue_struct *q,
107 struct diff_options *opt, void *data)
108{
109 int i;
620a6cd4 110 int *discard_flag = data;
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111
112 /* do_diff_cache() mangled the index */
113 discard_cache();
620a6cd4 114 *discard_flag = 1;
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115 read_cache();
116
117 for (i = 0; i < q->nr; i++) {
118 struct diff_filespec *one = q->queue[i]->one;
119 if (one->mode) {
120 struct cache_entry *ce;
121 ce = make_cache_entry(one->mode, one->sha1, one->path,
122 0, 0);
123 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
124 ADD_CACHE_OK_TO_REPLACE);
125 } else
126 remove_file_from_cache(one->path);
127 }
128}
129
130static int read_from_tree(const char *prefix, const char **argv,
131 unsigned char *tree_sha1)
132{
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133 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
134 int index_fd, index_was_discarded = 0;
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135 struct diff_options opt;
136
137 memset(&opt, 0, sizeof(opt));
138 diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
139 opt.output_format = DIFF_FORMAT_CALLBACK;
140 opt.format_callback = update_index_from_diff;
620a6cd4 141 opt.format_callback_data = &index_was_discarded;
0e5a7faa 142
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143 index_fd = hold_locked_index(lock, 1);
144 index_was_discarded = 0;
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145 read_cache();
146 if (do_diff_cache(tree_sha1, &opt))
147 return 1;
148 diffcore_std(&opt);
149 diff_flush(&opt);
03b69c76 150 diff_tree_release_paths(&opt);
2e7a9785 151
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152 if (!index_was_discarded)
153 /* The index is still clobbered from do_diff_cache() */
154 discard_cache();
155 return update_index_refresh(index_fd, lock);
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156}
157
158static void prepend_reflog_action(const char *action, char *buf, size_t size)
159{
160 const char *sep = ": ";
161 const char *rla = getenv("GIT_REFLOG_ACTION");
162 if (!rla)
163 rla = sep = "";
164 if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
165 warning("Reflog action message too long: %.*s...", 50, buf);
166}
167
168enum reset_type { MIXED, SOFT, HARD, NONE };
538dfe73 169static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
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170
171int cmd_reset(int argc, const char **argv, const char *prefix)
172{
5eee6b28 173 int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
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174 const char *rev = "HEAD";
175 unsigned char sha1[20], *orig = NULL, sha1_orig[20],
176 *old_orig = NULL, sha1_old_orig[20];
177 struct commit *commit;
178 char *reflog_action, msg[1024];
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179 const struct option options[] = {
180 OPT_SET_INT(0, "mixed", &reset_type,
181 "reset HEAD and index", MIXED),
182 OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
183 OPT_SET_INT(0, "hard", &reset_type,
184 "reset HEAD, index and working tree", HARD),
185 OPT_BOOLEAN('q', NULL, &quiet,
5aa965a0 186 "disable showing new HEAD in hard reset and progress message"),
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187 OPT_END()
188 };
0e5a7faa 189
ef90d6d4 190 git_config(git_default_config, NULL);
0e5a7faa 191
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192 argc = parse_options(argc, argv, options, git_reset_usage,
193 PARSE_OPT_KEEP_DASHDASH);
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194 reflog_action = args_to_str(argv);
195 setenv("GIT_REFLOG_ACTION", reflog_action, 0);
196
5eee6b28 197 if (i < argc && strcmp(argv[i], "--"))
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198 rev = argv[i++];
199
200 if (get_sha1(rev, sha1))
201 die("Failed to resolve '%s' as a valid ref.", rev);
202
203 commit = lookup_commit_reference(sha1);
204 if (!commit)
205 die("Could not parse object '%s'.", rev);
206 hashcpy(sha1, commit->object.sha1);
207
208 if (i < argc && !strcmp(argv[i], "--"))
209 i++;
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210
211 /* git reset tree [--] paths... can be used to
212 * load chosen paths from the tree into the index without
213 * affecting the working tree nor HEAD. */
214 if (i < argc) {
215 if (reset_type == MIXED)
216 warning("--mixed option is deprecated with paths.");
217 else if (reset_type != NONE)
218 die("Cannot do %s reset with paths.",
219 reset_type_names[reset_type]);
620a6cd4 220 return read_from_tree(prefix, argv + i, sha1);
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221 }
222 if (reset_type == NONE)
223 reset_type = MIXED; /* by default */
224
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225 if (reset_type == HARD && is_bare_repository())
226 die("hard reset makes no sense in a bare repository");
227
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228 /* Soft reset does not touch the index file nor the working tree
229 * at all, but requires them in a good order. Other resets reset
230 * the index file to the tree object we are switching to. */
231 if (reset_type == SOFT) {
94a5728c 232 if (is_merge() || read_cache() < 0 || unmerged_cache())
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233 die("Cannot do a soft reset in the middle of a merge.");
234 }
5aa965a0 235 else if (reset_index_file(sha1, (reset_type == HARD), quiet))
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236 die("Could not reset index file to revision '%s'.", rev);
237
238 /* Any resets update HEAD to the head being switched to,
239 * saving the previous head in ORIG_HEAD before. */
240 if (!get_sha1("ORIG_HEAD", sha1_old_orig))
241 old_orig = sha1_old_orig;
242 if (!get_sha1("HEAD", sha1_orig)) {
243 orig = sha1_orig;
244 prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
245 update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
246 }
247 else if (old_orig)
248 delete_ref("ORIG_HEAD", old_orig);
249 prepend_reflog_action("updating HEAD", msg, sizeof(msg));
250 update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
251
252 switch (reset_type) {
253 case HARD:
521b53e5 254 if (!update_ref_status && !quiet)
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255 print_new_head_line(commit);
256 break;
257 case SOFT: /* Nothing else to do. */
258 break;
259 case MIXED: /* Report what has not been updated. */
620a6cd4 260 update_index_refresh(0, NULL);
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261 break;
262 }
263
c369e7b8 264 remove_branch_state();
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265
266 free(reflog_action);
267
268 return update_ref_status;
269}