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