doc: fix naming of response-end-pkt
[git] / reset.c
1 #include "git-compat-util.h"
2 #include "cache-tree.h"
3 #include "lockfile.h"
4 #include "refs.h"
5 #include "reset.h"
6 #include "run-command.h"
7 #include "tree-walk.h"
8 #include "tree.h"
9 #include "unpack-trees.h"
10
11 int reset_head(struct repository *r, struct object_id *oid, const char *action,
12                const char *switch_to_branch, unsigned flags,
13                const char *reflog_orig_head, const char *reflog_head,
14                const char *default_reflog_action)
15 {
16         unsigned detach_head = flags & RESET_HEAD_DETACH;
17         unsigned reset_hard = flags & RESET_HEAD_HARD;
18         unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
19         unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
20         unsigned update_orig_head = flags & RESET_ORIG_HEAD;
21         struct object_id head_oid;
22         struct tree_desc desc[2] = { { NULL }, { NULL } };
23         struct lock_file lock = LOCK_INIT;
24         struct unpack_trees_options unpack_tree_opts;
25         struct tree *tree;
26         const char *reflog_action;
27         struct strbuf msg = STRBUF_INIT;
28         size_t prefix_len;
29         struct object_id *orig = NULL, oid_orig,
30                 *old_orig = NULL, oid_old_orig;
31         int ret = 0, nr = 0;
32
33         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
34                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
35
36         if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
37                 ret = -1;
38                 goto leave_reset_head;
39         }
40
41         if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
42                 ret = error(_("could not determine HEAD revision"));
43                 goto leave_reset_head;
44         }
45
46         if (!oid)
47                 oid = &head_oid;
48
49         if (refs_only)
50                 goto reset_head_refs;
51
52         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
53         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
54         unpack_tree_opts.head_idx = 1;
55         unpack_tree_opts.src_index = r->index;
56         unpack_tree_opts.dst_index = r->index;
57         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
58         unpack_tree_opts.update = 1;
59         unpack_tree_opts.merge = 1;
60         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
61         if (!detach_head)
62                 unpack_tree_opts.reset = 1;
63
64         if (repo_read_index_unmerged(r) < 0) {
65                 ret = error(_("could not read index"));
66                 goto leave_reset_head;
67         }
68
69         if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
70                 ret = error(_("failed to find tree of %s"),
71                             oid_to_hex(&head_oid));
72                 goto leave_reset_head;
73         }
74
75         if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
76                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
77                 goto leave_reset_head;
78         }
79
80         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
81                 ret = -1;
82                 goto leave_reset_head;
83         }
84
85         tree = parse_tree_indirect(oid);
86         prime_cache_tree(r, r->index, tree);
87
88         if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
89                 ret = error(_("could not write index"));
90                 goto leave_reset_head;
91         }
92
93 reset_head_refs:
94         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
95         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
96         prefix_len = msg.len;
97
98         if (update_orig_head) {
99                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
100                         old_orig = &oid_old_orig;
101                 if (!get_oid("HEAD", &oid_orig)) {
102                         orig = &oid_orig;
103                         if (!reflog_orig_head) {
104                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
105                                 reflog_orig_head = msg.buf;
106                         }
107                         update_ref(reflog_orig_head, "ORIG_HEAD", orig,
108                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
109                 } else if (old_orig)
110                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
111         }
112
113         if (!reflog_head) {
114                 strbuf_setlen(&msg, prefix_len);
115                 strbuf_addstr(&msg, "updating HEAD");
116                 reflog_head = msg.buf;
117         }
118         if (!switch_to_branch)
119                 ret = update_ref(reflog_head, "HEAD", oid, orig,
120                                  detach_head ? REF_NO_DEREF : 0,
121                                  UPDATE_REFS_MSG_ON_ERR);
122         else {
123                 ret = update_ref(reflog_head, switch_to_branch, oid,
124                                  NULL, 0, UPDATE_REFS_MSG_ON_ERR);
125                 if (!ret)
126                         ret = create_symref("HEAD", switch_to_branch,
127                                             reflog_head);
128         }
129         if (run_hook)
130                 run_hook_le(NULL, "post-checkout",
131                             oid_to_hex(orig ? orig : &null_oid),
132                             oid_to_hex(oid), "1", NULL);
133
134 leave_reset_head:
135         strbuf_release(&msg);
136         rollback_lock_file(&lock);
137         while (nr)
138                 free((void *)desc[--nr].buffer);
139         return ret;
140
141 }