Merge branch 'jn/gitweb-grep'
[git/git.git] / builtin-reset.c
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"
19 #include "branch.h"
20
21 static const char builtin_reset_usage[] =
22 "git-reset [--mixed | --soft | --hard] [-q] [<commit-ish>] [ [--] <paths>...]";
23
24 static char *args_to_str(const char **argv)
25 {
26 char *buf = NULL;
27 unsigned long len, space = 0, nr = 0;
28
29 for (; *argv; argv++) {
30 len = strlen(*argv);
31 ALLOC_GROW(buf, nr + 1 + len, space);
32 if (nr)
33 buf[nr++] = ' ';
34 memcpy(buf + nr, *argv, len);
35 nr += len;
36 }
37 ALLOC_GROW(buf, nr + 1, space);
38 buf[nr] = '\0';
39
40 return buf;
41 }
42
43 static inline int is_merge(void)
44 {
45 return !access(git_path("MERGE_HEAD"), F_OK);
46 }
47
48 static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
49 {
50 int i = 0;
51 const char *args[6];
52
53 args[i++] = "read-tree";
54 args[i++] = "-v";
55 args[i++] = "--reset";
56 if (is_hard_reset)
57 args[i++] = "-u";
58 args[i++] = sha1_to_hex(sha1);
59 args[i] = NULL;
60
61 return run_command_v_opt(args, RUN_GIT_CMD);
62 }
63
64 static void print_new_head_line(struct commit *commit)
65 {
66 const char *hex, *body;
67
68 hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
69 printf("HEAD is now at %s", hex);
70 body = strstr(commit->buffer, "\n\n");
71 if (body) {
72 const char *eol;
73 size_t len;
74 body += 2;
75 eol = strchr(body, '\n');
76 len = eol ? eol - body : strlen(body);
77 printf(" %.*s\n", (int) len, body);
78 }
79 else
80 printf("\n");
81 }
82
83 static int update_index_refresh(int fd, struct lock_file *index_lock)
84 {
85 int result;
86
87 if (!index_lock) {
88 index_lock = xcalloc(1, sizeof(struct lock_file));
89 fd = hold_locked_index(index_lock, 1);
90 }
91
92 if (read_cache() < 0)
93 return error("Could not read index");
94 result = refresh_cache(0) ? 1 : 0;
95 if (write_cache(fd, active_cache, active_nr) ||
96 commit_locked_index(index_lock))
97 return error ("Could not refresh index");
98 return result;
99 }
100
101 static void update_index_from_diff(struct diff_queue_struct *q,
102 struct diff_options *opt, void *data)
103 {
104 int i;
105 int *discard_flag = data;
106
107 /* do_diff_cache() mangled the index */
108 discard_cache();
109 *discard_flag = 1;
110 read_cache();
111
112 for (i = 0; i < q->nr; i++) {
113 struct diff_filespec *one = q->queue[i]->one;
114 if (one->mode) {
115 struct cache_entry *ce;
116 ce = make_cache_entry(one->mode, one->sha1, one->path,
117 0, 0);
118 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
119 ADD_CACHE_OK_TO_REPLACE);
120 } else
121 remove_file_from_cache(one->path);
122 }
123 }
124
125 static int read_from_tree(const char *prefix, const char **argv,
126 unsigned char *tree_sha1)
127 {
128 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
129 int index_fd, index_was_discarded = 0;
130 struct diff_options opt;
131
132 memset(&opt, 0, sizeof(opt));
133 diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
134 opt.output_format = DIFF_FORMAT_CALLBACK;
135 opt.format_callback = update_index_from_diff;
136 opt.format_callback_data = &index_was_discarded;
137
138 index_fd = hold_locked_index(lock, 1);
139 index_was_discarded = 0;
140 read_cache();
141 if (do_diff_cache(tree_sha1, &opt))
142 return 1;
143 diffcore_std(&opt);
144 diff_flush(&opt);
145 diff_tree_release_paths(&opt);
146
147 if (!index_was_discarded)
148 /* The index is still clobbered from do_diff_cache() */
149 discard_cache();
150 return update_index_refresh(index_fd, lock);
151 }
152
153 static void prepend_reflog_action(const char *action, char *buf, size_t size)
154 {
155 const char *sep = ": ";
156 const char *rla = getenv("GIT_REFLOG_ACTION");
157 if (!rla)
158 rla = sep = "";
159 if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
160 warning("Reflog action message too long: %.*s...", 50, buf);
161 }
162
163 enum reset_type { MIXED, SOFT, HARD, NONE };
164 static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
165
166 int cmd_reset(int argc, const char **argv, const char *prefix)
167 {
168 int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
169 const char *rev = "HEAD";
170 unsigned char sha1[20], *orig = NULL, sha1_orig[20],
171 *old_orig = NULL, sha1_old_orig[20];
172 struct commit *commit;
173 char *reflog_action, msg[1024];
174
175 git_config(git_default_config);
176
177 reflog_action = args_to_str(argv);
178 setenv("GIT_REFLOG_ACTION", reflog_action, 0);
179
180 while (i < argc) {
181 if (!strcmp(argv[i], "--mixed")) {
182 reset_type = MIXED;
183 i++;
184 }
185 else if (!strcmp(argv[i], "--soft")) {
186 reset_type = SOFT;
187 i++;
188 }
189 else if (!strcmp(argv[i], "--hard")) {
190 reset_type = HARD;
191 i++;
192 }
193 else if (!strcmp(argv[i], "-q")) {
194 quiet = 1;
195 i++;
196 }
197 else
198 break;
199 }
200
201 if (i < argc && argv[i][0] != '-')
202 rev = argv[i++];
203
204 if (get_sha1(rev, sha1))
205 die("Failed to resolve '%s' as a valid ref.", rev);
206
207 commit = lookup_commit_reference(sha1);
208 if (!commit)
209 die("Could not parse object '%s'.", rev);
210 hashcpy(sha1, commit->object.sha1);
211
212 if (i < argc && !strcmp(argv[i], "--"))
213 i++;
214 else if (i < argc && argv[i][0] == '-')
215 usage(builtin_reset_usage);
216
217 /* git reset tree [--] paths... can be used to
218 * load chosen paths from the tree into the index without
219 * affecting the working tree nor HEAD. */
220 if (i < argc) {
221 if (reset_type == MIXED)
222 warning("--mixed option is deprecated with paths.");
223 else if (reset_type != NONE)
224 die("Cannot do %s reset with paths.",
225 reset_type_names[reset_type]);
226 return read_from_tree(prefix, argv + i, sha1);
227 }
228 if (reset_type == NONE)
229 reset_type = MIXED; /* by default */
230
231 if (reset_type == HARD && is_bare_repository())
232 die("hard reset makes no sense in a bare repository");
233
234 /* Soft reset does not touch the index file nor the working tree
235 * at all, but requires them in a good order. Other resets reset
236 * the index file to the tree object we are switching to. */
237 if (reset_type == SOFT) {
238 if (is_merge() || read_cache() < 0 || unmerged_cache())
239 die("Cannot do a soft reset in the middle of a merge.");
240 }
241 else if (reset_index_file(sha1, (reset_type == HARD)))
242 die("Could not reset index file to revision '%s'.", rev);
243
244 /* Any resets update HEAD to the head being switched to,
245 * saving the previous head in ORIG_HEAD before. */
246 if (!get_sha1("ORIG_HEAD", sha1_old_orig))
247 old_orig = sha1_old_orig;
248 if (!get_sha1("HEAD", sha1_orig)) {
249 orig = sha1_orig;
250 prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
251 update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
252 }
253 else if (old_orig)
254 delete_ref("ORIG_HEAD", old_orig);
255 prepend_reflog_action("updating HEAD", msg, sizeof(msg));
256 update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
257
258 switch (reset_type) {
259 case HARD:
260 if (!update_ref_status && !quiet)
261 print_new_head_line(commit);
262 break;
263 case SOFT: /* Nothing else to do. */
264 break;
265 case MIXED: /* Report what has not been updated. */
266 update_index_refresh(0, NULL);
267 break;
268 }
269
270 remove_branch_state();
271
272 free(reflog_action);
273
274 return update_ref_status;
275 }