diff: do not use null sha1 as a sentinel value
[git/git.git] / builtin / read-tree.c
CommitLineData
8bc9a0c7
LT
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
4d3fe0c5 6
e83c5163 7#include "cache.h"
ee6566e8
DB
8#include "object.h"
9#include "tree.h"
1ccf5a34 10#include "tree-walk.h"
bad68ec9 11#include "cache-tree.h"
16da134b 12#include "unpack-trees.h"
f8a9d428 13#include "dir.h"
d147e501 14#include "builtin.h"
5a56da58 15#include "parse-options.h"
cfc5789a 16#include "resolve-undo.h"
ee6566e8 17
933bf40a 18static int nr_trees;
fb1bb965 19static int read_empty;
ca885a4f 20static struct tree *trees[MAX_UNPACK_TREES];
ee6566e8 21
ee6566e8
DB
22static int list_tree(unsigned char *sha1)
23{
933bf40a
LT
24 struct tree *tree;
25
ca885a4f
JH
26 if (nr_trees >= MAX_UNPACK_TREES)
27 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
933bf40a 28 tree = parse_tree_indirect(sha1);
ee6566e8
DB
29 if (!tree)
30 return -1;
933bf40a 31 trees[nr_trees++] = tree;
ee6566e8
DB
32 return 0;
33}
34
5a56da58 35static const char * const read_tree_usage[] = {
fb1bb965 36 "git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])",
5a56da58
SB
37 NULL
38};
39
40static int index_output_cb(const struct option *opt, const char *arg,
41 int unset)
42{
43 set_alternate_index_output(arg);
44 return 0;
45}
46
47static int exclude_per_directory_cb(const struct option *opt, const char *arg,
48 int unset)
49{
50 struct dir_struct *dir;
51 struct unpack_trees_options *opts;
52
53 opts = (struct unpack_trees_options *)opt->value;
54
55 if (opts->dir)
56 die("more than one --exclude-per-directory given.");
57
58 dir = xcalloc(1, sizeof(*opts->dir));
59 dir->flags |= DIR_SHOW_IGNORED;
60 dir->exclude_per_dir = arg;
61 opts->dir = dir;
62 /* We do not need to nor want to do read-directory
63 * here; we are merely interested in reusing the
64 * per directory ignore stack mechanism.
65 */
66 return 0;
67}
c5bac17a 68
ba655da5
JH
69static void debug_stage(const char *label, struct cache_entry *ce,
70 struct unpack_trees_options *o)
71{
72 printf("%s ", label);
73 if (!ce)
74 printf("(missing)\n");
75 else if (ce == o->df_conflict_entry)
76 printf("(conflict)\n");
77 else
78 printf("%06o #%d %s %.8s\n",
79 ce->ce_mode, ce_stage(ce), ce->name,
80 sha1_to_hex(ce->sha1));
81}
82
83static int debug_merge(struct cache_entry **stages, struct unpack_trees_options *o)
84{
85 int i;
86
87 printf("* %d-way merge\n", o->merge_size);
88 debug_stage("index", stages[0], o);
89 for (i = 1; i <= o->merge_size; i++) {
90 char buf[24];
91 sprintf(buf, "ent#%d", i);
92 debug_stage(buf, stages[i], o);
93 }
94 return 0;
95}
96
021b6e45 97static struct lock_file lock_file;
96cd5429 98
a91af794 99int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
e83c5163 100{
6d6776cb 101 int i, newfd, stage = 0;
e83c5163 102 unsigned char sha1[20];
ca885a4f 103 struct tree_desc t[MAX_UNPACK_TREES];
16da134b 104 struct unpack_trees_options opts;
5a56da58
SB
105 int prefix_set = 0;
106 const struct option read_tree_options[] = {
23c6a803
MG
107 { OPTION_CALLBACK, 0, "index-output", NULL, "file",
108 "write resulting index to <file>",
5a56da58 109 PARSE_OPT_NONEG, index_output_cb },
fb1bb965
JK
110 OPT_SET_INT(0, "empty", &read_empty,
111 "only empty the index", 1),
fd03881a 112 OPT__VERBOSE(&opts.verbose_update, "be verbose"),
5a56da58
SB
113 OPT_GROUP("Merging"),
114 OPT_SET_INT('m', NULL, &opts.merge,
115 "perform a merge in addition to a read", 1),
116 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
117 "3-way merge if no file level merging required", 1),
118 OPT_SET_INT(0, "aggressive", &opts.aggressive,
119 "3-way merge in presence of adds and removes", 1),
120 OPT_SET_INT(0, "reset", &opts.reset,
121 "same as -m, but discard unmerged entries", 1),
122 { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
123 "read the tree into the index under <subdirectory>/",
124 PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
125 OPT_SET_INT('u', NULL, &opts.update,
126 "update working tree with merge result", 1),
127 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
128 "gitignore",
129 "allow explicitly ignored files to be overwritten",
130 PARSE_OPT_NONEG, exclude_per_directory_cb },
131 OPT_SET_INT('i', NULL, &opts.index_only,
132 "don't check the working tree after merging", 1),
ea5070c9 133 OPT__DRY_RUN(&opts.dry_run, "don't update the index or the work tree"),
a5d07d0f
NTND
134 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
135 "skip applying sparse checkout filter", 1),
ba655da5
JH
136 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
137 "debug unpack-trees", 1),
5a56da58
SB
138 OPT_END()
139 };
bb233d69 140
16da134b
JS
141 memset(&opts, 0, sizeof(opts));
142 opts.head_idx = -1;
34110cd4
LT
143 opts.src_index = &the_index;
144 opts.dst_index = &the_index;
344c52ae 145
ef90d6d4 146 git_config(git_default_config, NULL);
53228a5f 147
5a56da58
SB
148 argc = parse_options(argc, argv, unused_prefix, read_tree_options,
149 read_tree_usage, 0);
83adac3c 150
99caeed0
JN
151 newfd = hold_locked_index(&lock_file, 1);
152
5a56da58
SB
153 prefix_set = opts.prefix ? 1 : 0;
154 if (1 < opts.merge + opts.reset + prefix_set)
155 die("Which one? -m, --reset, or --prefix?");
db137fe9
AJ
156
157 if (opts.reset || opts.merge || opts.prefix) {
158 if (read_cache_unmerged() && (opts.prefix || opts.merge))
159 die("You need to resolve your current index first");
160 stage = opts.merge = 1;
161 }
cfc5789a 162 resolve_undo_clear();
5a56da58
SB
163
164 for (i = 0; i < argc; i++) {
165 const char *arg = argv[i];
720d150c 166
31fff305
DL
167 if (get_sha1(arg, sha1))
168 die("Not a valid object name %s", arg);
ee6566e8 169 if (list_tree(sha1) < 0)
2de381f9 170 die("failed to unpack tree object %s", arg);
d99082e0 171 stage++;
83adac3c 172 }
fb1bb965
JK
173 if (nr_trees == 0 && !read_empty)
174 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
175 else if (nr_trees > 0 && read_empty)
176 die("passing trees as arguments contradicts --empty");
177
5a56da58
SB
178 if (1 < opts.index_only + opts.update)
179 die("-u and -i at the same time makes no sense");
16da134b 180 if ((opts.update||opts.index_only) && !opts.merge)
a429d2dd
SB
181 die("%s is meaningless without -m, --reset, or --prefix",
182 opts.update ? "-u" : "-i");
f8a9d428
JH
183 if ((opts.dir && !opts.update))
184 die("--exclude-per-directory is meaningless unless -u");
b6469a81
NTND
185 if (opts.merge && !opts.index_only)
186 setup_work_tree();
7dd43575 187
16da134b 188 if (opts.merge) {
ee6566e8 189 if (stage < 2)
a3a65234 190 die("just how do you expect me to merge %d trees?", stage-1);
ee6566e8
DB
191 switch (stage - 1) {
192 case 1:
16da134b 193 opts.fn = opts.prefix ? bind_merge : oneway_merge;
ee6566e8
DB
194 break;
195 case 2:
16da134b 196 opts.fn = twoway_merge;
fa7b3c2f 197 opts.initial_checkout = is_cache_unborn();
ee6566e8
DB
198 break;
199 case 3:
ee6566e8 200 default:
16da134b 201 opts.fn = threeway_merge;
ee6566e8 202 break;
03efa6d9 203 }
ee6566e8 204
ee6566e8 205 if (stage - 1 >= 3)
16da134b 206 opts.head_idx = stage - 2;
ee6566e8 207 else
16da134b 208 opts.head_idx = 1;
ee6566e8
DB
209 }
210
ba655da5
JH
211 if (opts.debug_unpack)
212 opts.fn = debug_merge;
213
8cc21ce7 214 cache_tree_free(&active_cache_tree);
933bf40a
LT
215 for (i = 0; i < nr_trees; i++) {
216 struct tree *tree = trees[i];
217 parse_tree(tree);
218 init_tree_desc(t+i, tree->buffer, tree->size);
219 }
203a2fe1
DB
220 if (unpack_trees(nr_trees, t, &opts))
221 return 128;
7927a55d 222
ea5070c9 223 if (opts.debug_unpack || opts.dry_run)
ba655da5
JH
224 return 0; /* do not write the index out */
225
7927a55d
JH
226 /*
227 * When reading only one tree (either the most basic form,
228 * "-m ent" or "--reset ent" form), we can obtain a fully
229 * valid cache-tree because the index must match exactly
230 * what came from the tree.
231 */
8cc21ce7 232 if (nr_trees == 1 && !opts.prefix)
b9d37a54 233 prime_cache_tree(&active_cache_tree, trees[0]);
7927a55d 234
96cd5429 235 if (write_cache(newfd, active_cache, active_nr) ||
4ed7cd3a 236 commit_locked_index(&lock_file))
2de381f9 237 die("unable to write new index file");
9614b8dc 238 return 0;
e83c5163 239}