Reteach builtin-ls-remote to understand remotes
[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
20 static const char builtin_reset_usage[] =
21 "git-reset [--mixed | --soft | --hard] [<commit-ish>] [ [--] <paths>...]";
22
23 static char *args_to_str(const char **argv)
24 {
25 char *buf = NULL;
26 unsigned long len, space = 0, nr = 0;
27
28 for (; *argv; argv++) {
29 len = strlen(*argv);
30 ALLOC_GROW(buf, nr + 1 + len, space);
31 if (nr)
32 buf[nr++] = ' ';
33 memcpy(buf + nr, *argv, len);
34 nr += len;
35 }
36 ALLOC_GROW(buf, nr + 1, space);
37 buf[nr] = '\0';
38
39 return buf;
40 }
41
42 static inline int is_merge(void)
43 {
44 return !access(git_path("MERGE_HEAD"), F_OK);
45 }
46
47 static int unmerged_files(void)
48 {
49 char b;
50 ssize_t len;
51 struct child_process cmd;
52 const char *argv_ls_files[] = {"ls-files", "--unmerged", NULL};
53
54 memset(&cmd, 0, sizeof(cmd));
55 cmd.argv = argv_ls_files;
56 cmd.git_cmd = 1;
57 cmd.out = -1;
58
59 if (start_command(&cmd))
60 die("Could not run sub-command: git ls-files");
61
62 len = xread(cmd.out, &b, 1);
63 if (len < 0)
64 die("Could not read output from git ls-files: %s",
65 strerror(errno));
66 finish_command(&cmd);
67
68 return len;
69 }
70
71 static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
72 {
73 int i = 0;
74 const char *args[6];
75
76 args[i++] = "read-tree";
77 args[i++] = "-v";
78 args[i++] = "--reset";
79 if (is_hard_reset)
80 args[i++] = "-u";
81 args[i++] = sha1_to_hex(sha1);
82 args[i] = NULL;
83
84 return run_command_v_opt(args, RUN_GIT_CMD);
85 }
86
87 static void print_new_head_line(struct commit *commit)
88 {
89 const char *hex, *dots = "...", *body;
90
91 hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
92 if (!hex) {
93 hex = sha1_to_hex(commit->object.sha1);
94 dots = "";
95 }
96 printf("HEAD is now at %s%s", hex, dots);
97 body = strstr(commit->buffer, "\n\n");
98 if (body) {
99 const char *eol;
100 size_t len;
101 body += 2;
102 eol = strchr(body, '\n');
103 len = eol ? eol - body : strlen(body);
104 printf(" %.*s\n", (int) len, body);
105 }
106 else
107 printf("\n");
108 }
109
110 static int update_index_refresh(void)
111 {
112 const char *argv_update_index[] = {"update-index", "--refresh", NULL};
113 return run_command_v_opt(argv_update_index, RUN_GIT_CMD);
114 }
115
116 static void update_index_from_diff(struct diff_queue_struct *q,
117 struct diff_options *opt, void *data)
118 {
119 int i;
120
121 /* do_diff_cache() mangled the index */
122 discard_cache();
123 read_cache();
124
125 for (i = 0; i < q->nr; i++) {
126 struct diff_filespec *one = q->queue[i]->one;
127 if (one->mode) {
128 struct cache_entry *ce;
129 ce = make_cache_entry(one->mode, one->sha1, one->path,
130 0, 0);
131 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
132 ADD_CACHE_OK_TO_REPLACE);
133 } else
134 remove_file_from_cache(one->path);
135 }
136 }
137
138 static int read_from_tree(const char *prefix, const char **argv,
139 unsigned char *tree_sha1)
140 {
141 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
142 int index_fd;
143 struct diff_options opt;
144
145 memset(&opt, 0, sizeof(opt));
146 diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
147 opt.output_format = DIFF_FORMAT_CALLBACK;
148 opt.format_callback = update_index_from_diff;
149
150 index_fd = hold_locked_index(lock, 1);
151 read_cache();
152 if (do_diff_cache(tree_sha1, &opt))
153 return 1;
154 diffcore_std(&opt);
155 diff_flush(&opt);
156 return write_cache(index_fd, active_cache, active_nr) ||
157 close(index_fd) ||
158 commit_locked_index(lock);
159 }
160
161 static void prepend_reflog_action(const char *action, char *buf, size_t size)
162 {
163 const char *sep = ": ";
164 const char *rla = getenv("GIT_REFLOG_ACTION");
165 if (!rla)
166 rla = sep = "";
167 if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
168 warning("Reflog action message too long: %.*s...", 50, buf);
169 }
170
171 enum reset_type { MIXED, SOFT, HARD, NONE };
172 static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
173
174 int cmd_reset(int argc, const char **argv, const char *prefix)
175 {
176 int i = 1, reset_type = NONE, update_ref_status = 0;
177 const char *rev = "HEAD";
178 unsigned char sha1[20], *orig = NULL, sha1_orig[20],
179 *old_orig = NULL, sha1_old_orig[20];
180 struct commit *commit;
181 char *reflog_action, msg[1024];
182
183 git_config(git_default_config);
184
185 reflog_action = args_to_str(argv);
186 setenv("GIT_REFLOG_ACTION", reflog_action, 0);
187
188 if (i < argc) {
189 if (!strcmp(argv[i], "--mixed")) {
190 reset_type = MIXED;
191 i++;
192 }
193 else if (!strcmp(argv[i], "--soft")) {
194 reset_type = SOFT;
195 i++;
196 }
197 else if (!strcmp(argv[i], "--hard")) {
198 reset_type = HARD;
199 i++;
200 }
201 }
202
203 if (i < argc && argv[i][0] != '-')
204 rev = argv[i++];
205
206 if (get_sha1(rev, sha1))
207 die("Failed to resolve '%s' as a valid ref.", rev);
208
209 commit = lookup_commit_reference(sha1);
210 if (!commit)
211 die("Could not parse object '%s'.", rev);
212 hashcpy(sha1, commit->object.sha1);
213
214 if (i < argc && !strcmp(argv[i], "--"))
215 i++;
216 else if (i < argc && argv[i][0] == '-')
217 usage(builtin_reset_usage);
218
219 /* git reset tree [--] paths... can be used to
220 * load chosen paths from the tree into the index without
221 * affecting the working tree nor HEAD. */
222 if (i < argc) {
223 if (reset_type == MIXED)
224 warning("--mixed option is deprecated with paths.");
225 else if (reset_type != NONE)
226 die("Cannot do %s reset with paths.",
227 reset_type_names[reset_type]);
228 if (read_from_tree(prefix, argv + i, sha1))
229 return 1;
230 return update_index_refresh() ? 1 : 0;
231 }
232 if (reset_type == NONE)
233 reset_type = MIXED; /* by default */
234
235 /* Soft reset does not touch the index file nor the working tree
236 * at all, but requires them in a good order. Other resets reset
237 * the index file to the tree object we are switching to. */
238 if (reset_type == SOFT) {
239 if (is_merge() || unmerged_files())
240 die("Cannot do a soft reset in the middle of a merge.");
241 }
242 else if (reset_index_file(sha1, (reset_type == HARD)))
243 die("Could not reset index file to revision '%s'.", rev);
244
245 /* Any resets update HEAD to the head being switched to,
246 * saving the previous head in ORIG_HEAD before. */
247 if (!get_sha1("ORIG_HEAD", sha1_old_orig))
248 old_orig = sha1_old_orig;
249 if (!get_sha1("HEAD", sha1_orig)) {
250 orig = sha1_orig;
251 prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
252 update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
253 }
254 else if (old_orig)
255 delete_ref("ORIG_HEAD", old_orig);
256 prepend_reflog_action("updating HEAD", msg, sizeof(msg));
257 update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
258
259 switch (reset_type) {
260 case HARD:
261 if (!update_ref_status)
262 print_new_head_line(commit);
263 break;
264 case SOFT: /* Nothing else to do. */
265 break;
266 case MIXED: /* Report what has not been updated. */
267 update_index_refresh();
268 break;
269 }
270
271 unlink(git_path("MERGE_HEAD"));
272 unlink(git_path("rr-cache/MERGE_RR"));
273 unlink(git_path("MERGE_MSG"));
274 unlink(git_path("SQUASH_MSG"));
275
276 free(reflog_action);
277
278 return update_ref_status;
279 }