Teach notes code to properly preserve non-notes in the notes tree
[git] / builtin-notes.c
1 /*
2  * Builtin "git notes"
3  *
4  * Copyright (c) 2010 Johan Herland <johan@herland.net>
5  *
6  * Based on git-notes.sh by Johannes Schindelin,
7  * and builtin-tag.c by Kristian Høgsberg and Carlos Rica.
8  */
9
10 #include "cache.h"
11 #include "builtin.h"
12 #include "notes.h"
13 #include "blob.h"
14 #include "commit.h"
15 #include "refs.h"
16 #include "exec_cmd.h"
17 #include "run-command.h"
18 #include "parse-options.h"
19
20 static const char * const git_notes_usage[] = {
21         "git notes edit [-m <msg> | -F <file>] [<object>]",
22         "git notes show [<object>]",
23         NULL
24 };
25
26 static const char note_template[] =
27         "\n"
28         "#\n"
29         "# Write/edit the notes for the following object:\n"
30         "#\n";
31
32 static void write_note_data(int fd, const unsigned char *sha1)
33 {
34         unsigned long size;
35         enum object_type type;
36         char *buf = read_sha1_file(sha1, &type, &size);
37         if (buf) {
38                 if (size)
39                         write_or_die(fd, buf, size);
40                 free(buf);
41         }
42 }
43
44 static void write_commented_object(int fd, const unsigned char *object)
45 {
46         const char *show_args[5] =
47                 {"show", "--stat", "--no-notes", sha1_to_hex(object), NULL};
48         struct child_process show;
49         struct strbuf buf = STRBUF_INIT;
50         FILE *show_out;
51
52         /* Invoke "git show --stat --no-notes $object" */
53         memset(&show, 0, sizeof(show));
54         show.argv = show_args;
55         show.no_stdin = 1;
56         show.out = -1;
57         show.err = 0;
58         show.git_cmd = 1;
59         if (start_command(&show))
60                 die("unable to start 'show' for object '%s'",
61                     sha1_to_hex(object));
62
63         /* Open the output as FILE* so strbuf_getline() can be used. */
64         show_out = xfdopen(show.out, "r");
65         if (show_out == NULL)
66                 die_errno("can't fdopen 'show' output fd");
67
68         /* Prepend "# " to each output line and write result to 'fd' */
69         while (strbuf_getline(&buf, show_out, '\n') != EOF) {
70                 write_or_die(fd, "# ", 2);
71                 write_or_die(fd, buf.buf, buf.len);
72                 write_or_die(fd, "\n", 1);
73         }
74         strbuf_release(&buf);
75         if (fclose(show_out))
76                 die_errno("failed to close pipe to 'show' for object '%s'",
77                           sha1_to_hex(object));
78         if (finish_command(&show))
79                 die("failed to finish 'show' for object '%s'",
80                     sha1_to_hex(object));
81 }
82
83 static void create_note(const unsigned char *object,
84                         struct strbuf *buf,
85                         int skip_editor,
86                         const unsigned char *prev,
87                         unsigned char *result)
88 {
89         char *path = NULL;
90
91         if (!skip_editor) {
92                 int fd;
93
94                 /* write the template message before editing: */
95                 path = git_pathdup("NOTES_EDITMSG");
96                 fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
97                 if (fd < 0)
98                         die_errno("could not create file '%s'", path);
99
100                 if (prev)
101                         write_note_data(fd, prev);
102                 write_or_die(fd, note_template, strlen(note_template));
103
104                 write_commented_object(fd, object);
105
106                 close(fd);
107
108                 if (launch_editor(path, buf, NULL)) {
109                         die("Please supply the note contents using either -m" \
110                             " or -F option");
111                 }
112         }
113
114         stripspace(buf, 1);
115
116         if (!skip_editor && !buf->len) {
117                 fprintf(stderr, "Removing note for object %s\n",
118                         sha1_to_hex(object));
119                 hashclr(result);
120         } else {
121                 if (write_sha1_file(buf->buf, buf->len, blob_type, result)) {
122                         error("unable to write note object");
123                         if (path)
124                                 error("The note contents has been left in %s",
125                                       path);
126                         exit(128);
127                 }
128         }
129
130         if (path) {
131                 unlink_or_warn(path);
132                 free(path);
133         }
134 }
135
136 struct msg_arg {
137         int given;
138         struct strbuf buf;
139 };
140
141 static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
142 {
143         struct msg_arg *msg = opt->value;
144
145         if (!arg)
146                 return -1;
147         if (msg->buf.len)
148                 strbuf_addstr(&(msg->buf), "\n\n");
149         strbuf_addstr(&(msg->buf), arg);
150         msg->given = 1;
151         return 0;
152 }
153
154 int commit_notes(struct notes_tree *t, const char *msg)
155 {
156         struct commit_list *parent;
157         unsigned char tree_sha1[20], prev_commit[20], new_commit[20];
158         struct strbuf buf = STRBUF_INIT;
159
160         if (!t)
161                 t = &default_notes_tree;
162         if (!t->initialized || !t->ref || !*t->ref)
163                 die("Cannot commit uninitialized/unreferenced notes tree");
164
165         /* Prepare commit message and reflog message */
166         strbuf_addstr(&buf, "notes: "); /* commit message starts at index 7 */
167         strbuf_addstr(&buf, msg);
168         if (buf.buf[buf.len - 1] != '\n')
169                 strbuf_addch(&buf, '\n'); /* Make sure msg ends with newline */
170
171         /* Convert notes tree to tree object */
172         if (write_notes_tree(t, tree_sha1))
173                 die("Failed to write current notes tree to database");
174
175         /* Create new commit for the tree object */
176         if (!read_ref(t->ref, prev_commit)) { /* retrieve parent commit */
177                 parent = xmalloc(sizeof(*parent));
178                 parent->item = lookup_commit(prev_commit);
179                 parent->next = NULL;
180         } else {
181                 hashclr(prev_commit);
182                 parent = NULL;
183         }
184         if (commit_tree(buf.buf + 7, tree_sha1, parent, new_commit, NULL))
185                 die("Failed to commit notes tree to database");
186
187         /* Update notes ref with new commit */
188         update_ref(buf.buf, t->ref, new_commit, prev_commit, 0, DIE_ON_ERR);
189
190         strbuf_release(&buf);
191         return 0;
192 }
193
194 int cmd_notes(int argc, const char **argv, const char *prefix)
195 {
196         struct strbuf buf = STRBUF_INIT;
197         struct notes_tree *t;
198         unsigned char object[20], new_note[20];
199         const unsigned char *note;
200         const char *object_ref;
201         int edit = 0, show = 0;
202         const char *msgfile = NULL;
203         struct msg_arg msg = { 0, STRBUF_INIT };
204         struct option options[] = {
205                 OPT_GROUP("Notes edit options"),
206                 OPT_CALLBACK('m', NULL, &msg, "msg",
207                              "note contents as a string", parse_msg_arg),
208                 OPT_FILENAME('F', NULL, &msgfile, "note contents in a file"),
209                 OPT_END()
210         };
211
212         git_config(git_default_config, NULL);
213
214         argc = parse_options(argc, argv, prefix, options, git_notes_usage, 0);
215
216         if (argc && !strcmp(argv[0], "edit"))
217                 edit = 1;
218         else if (argc && !strcmp(argv[0], "show"))
219                 show = 1;
220
221         if (edit + show != 1)
222                 usage_with_options(git_notes_usage, options);
223
224         object_ref = argc == 2 ? argv[1] : "HEAD";
225         if (argc > 2) {
226                 error("too many parameters");
227                 usage_with_options(git_notes_usage, options);
228         }
229
230         if (get_sha1(object_ref, object))
231                 die("Failed to resolve '%s' as a valid ref.", object_ref);
232
233         init_notes(NULL, NULL, NULL, 0);
234         t = &default_notes_tree;
235
236         if (prefixcmp(t->ref, "refs/notes/"))
237                 die("Refusing to %s notes in %s (outside of refs/notes/)",
238                     edit ? "edit" : "show", t->ref);
239
240         note = get_note(t, object);
241
242         /* show command */
243
244         if (show && !note) {
245                 error("No note found for object %s.", sha1_to_hex(object));
246                 return 1;
247         } else if (show) {
248                 const char *show_args[3] = {"show", sha1_to_hex(note), NULL};
249                 return execv_git_cmd(show_args);
250         }
251
252         /* edit command */
253
254         if (msg.given || msgfile) {
255                 if (msg.given && msgfile) {
256                         error("mixing -m and -F options is not allowed.");
257                         usage_with_options(git_notes_usage, options);
258                 }
259                 if (msg.given)
260                         strbuf_addbuf(&buf, &(msg.buf));
261                 else {
262                         if (!strcmp(msgfile, "-")) {
263                                 if (strbuf_read(&buf, 0, 1024) < 0)
264                                         die_errno("cannot read '%s'", msgfile);
265                         } else {
266                                 if (strbuf_read_file(&buf, msgfile, 1024) < 0)
267                                         die_errno("could not open or read '%s'",
268                                                 msgfile);
269                         }
270                 }
271         }
272
273         create_note(object, &buf, msg.given || msgfile, note, new_note);
274         add_note(t, object, new_note, combine_notes_overwrite);
275         commit_notes(t, "Note added by 'git notes edit'");
276
277         free_notes(t);
278         strbuf_release(&buf);
279         return 0;
280 }