reflog-walk: don't segfault on non-commit sha1's in the reflog
[git] / reflog-walk.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "refs.h"
4 #include "diff.h"
5 #include "revision.h"
6 #include "string-list.h"
7 #include "reflog-walk.h"
8
9 struct complete_reflogs {
10         char *ref;
11         const char *short_ref;
12         struct reflog_info {
13                 unsigned char osha1[20], nsha1[20];
14                 char *email;
15                 unsigned long timestamp;
16                 int tz;
17                 char *message;
18         } *items;
19         int nr, alloc;
20 };
21
22 static int read_one_reflog(unsigned char *osha1, unsigned char *nsha1,
23                 const char *email, unsigned long timestamp, int tz,
24                 const char *message, void *cb_data)
25 {
26         struct complete_reflogs *array = cb_data;
27         struct reflog_info *item;
28
29         ALLOC_GROW(array->items, array->nr + 1, array->alloc);
30         item = array->items + array->nr;
31         hashcpy(item->osha1, osha1);
32         hashcpy(item->nsha1, nsha1);
33         item->email = xstrdup(email);
34         item->timestamp = timestamp;
35         item->tz = tz;
36         item->message = xstrdup(message);
37         array->nr++;
38         return 0;
39 }
40
41 static struct complete_reflogs *read_complete_reflog(const char *ref)
42 {
43         struct complete_reflogs *reflogs =
44                 xcalloc(1, sizeof(struct complete_reflogs));
45         reflogs->ref = xstrdup(ref);
46         for_each_reflog_ent(ref, read_one_reflog, reflogs);
47         if (reflogs->nr == 0) {
48                 unsigned char sha1[20];
49                 const char *name;
50                 void *name_to_free;
51                 name = name_to_free = resolve_refdup(ref, RESOLVE_REF_READING,
52                                                      sha1, NULL);
53                 if (name) {
54                         for_each_reflog_ent(name, read_one_reflog, reflogs);
55                         free(name_to_free);
56                 }
57         }
58         if (reflogs->nr == 0) {
59                 int len = strlen(ref);
60                 char *refname = xmalloc(len + 12);
61                 sprintf(refname, "refs/%s", ref);
62                 for_each_reflog_ent(refname, read_one_reflog, reflogs);
63                 if (reflogs->nr == 0) {
64                         sprintf(refname, "refs/heads/%s", ref);
65                         for_each_reflog_ent(refname, read_one_reflog, reflogs);
66                 }
67                 free(refname);
68         }
69         return reflogs;
70 }
71
72 static int get_reflog_recno_by_time(struct complete_reflogs *array,
73         unsigned long timestamp)
74 {
75         int i;
76         for (i = array->nr - 1; i >= 0; i--)
77                 if (timestamp >= array->items[i].timestamp)
78                         return i;
79         return -1;
80 }
81
82 struct commit_info_lifo {
83         struct commit_info {
84                 struct commit *commit;
85                 void *util;
86         } *items;
87         int nr, alloc;
88 };
89
90 static struct commit_info *get_commit_info(struct commit *commit,
91                 struct commit_info_lifo *lifo, int pop)
92 {
93         int i;
94         for (i = 0; i < lifo->nr; i++)
95                 if (lifo->items[i].commit == commit) {
96                         struct commit_info *result = &lifo->items[i];
97                         if (pop) {
98                                 if (i + 1 < lifo->nr)
99                                         memmove(lifo->items + i,
100                                                 lifo->items + i + 1,
101                                                 (lifo->nr - i) *
102                                                 sizeof(struct commit_info));
103                                 lifo->nr--;
104                         }
105                         return result;
106                 }
107         return NULL;
108 }
109
110 static void add_commit_info(struct commit *commit, void *util,
111                 struct commit_info_lifo *lifo)
112 {
113         struct commit_info *info;
114         ALLOC_GROW(lifo->items, lifo->nr + 1, lifo->alloc);
115         info = lifo->items + lifo->nr;
116         info->commit = commit;
117         info->util = util;
118         lifo->nr++;
119 }
120
121 struct commit_reflog {
122         int recno;
123         enum selector_type {
124                 SELECTOR_NONE,
125                 SELECTOR_INDEX,
126                 SELECTOR_DATE
127         } selector;
128         struct complete_reflogs *reflogs;
129 };
130
131 struct reflog_walk_info {
132         struct commit_info_lifo reflogs;
133         struct string_list complete_reflogs;
134         struct commit_reflog *last_commit_reflog;
135 };
136
137 void init_reflog_walk(struct reflog_walk_info **info)
138 {
139         *info = xcalloc(1, sizeof(struct reflog_walk_info));
140 }
141
142 int add_reflog_for_walk(struct reflog_walk_info *info,
143                 struct commit *commit, const char *name)
144 {
145         unsigned long timestamp = 0;
146         int recno = -1;
147         struct string_list_item *item;
148         struct complete_reflogs *reflogs;
149         char *branch, *at = strchr(name, '@');
150         struct commit_reflog *commit_reflog;
151         enum selector_type selector = SELECTOR_NONE;
152
153         if (commit->object.flags & UNINTERESTING)
154                 die ("Cannot walk reflogs for %s", name);
155
156         branch = xstrdup(name);
157         if (at && at[1] == '{') {
158                 char *ep;
159                 branch[at - name] = '\0';
160                 recno = strtoul(at + 2, &ep, 10);
161                 if (*ep != '}') {
162                         recno = -1;
163                         timestamp = approxidate(at + 2);
164                         selector = SELECTOR_DATE;
165                 }
166                 else
167                         selector = SELECTOR_INDEX;
168         } else
169                 recno = 0;
170
171         item = string_list_lookup(&info->complete_reflogs, branch);
172         if (item)
173                 reflogs = item->util;
174         else {
175                 if (*branch == '\0') {
176                         unsigned char sha1[20];
177                         free(branch);
178                         branch = resolve_refdup("HEAD", 0, sha1, NULL);
179                         if (!branch)
180                                 die ("No current branch");
181
182                 }
183                 reflogs = read_complete_reflog(branch);
184                 if (!reflogs || reflogs->nr == 0) {
185                         unsigned char sha1[20];
186                         char *b;
187                         if (dwim_log(branch, strlen(branch), sha1, &b) == 1) {
188                                 if (reflogs) {
189                                         free(reflogs->ref);
190                                         free(reflogs);
191                                 }
192                                 free(branch);
193                                 branch = b;
194                                 reflogs = read_complete_reflog(branch);
195                         }
196                 }
197                 if (!reflogs || reflogs->nr == 0)
198                         return -1;
199                 string_list_insert(&info->complete_reflogs, branch)->util
200                         = reflogs;
201         }
202
203         commit_reflog = xcalloc(1, sizeof(struct commit_reflog));
204         if (recno < 0) {
205                 commit_reflog->recno = get_reflog_recno_by_time(reflogs, timestamp);
206                 if (commit_reflog->recno < 0) {
207                         free(branch);
208                         free(commit_reflog);
209                         return -1;
210                 }
211         } else
212                 commit_reflog->recno = reflogs->nr - recno - 1;
213         commit_reflog->selector = selector;
214         commit_reflog->reflogs = reflogs;
215
216         add_commit_info(commit, commit_reflog, &info->reflogs);
217         return 0;
218 }
219
220 void fake_reflog_parent(struct reflog_walk_info *info, struct commit *commit)
221 {
222         struct commit_info *commit_info =
223                 get_commit_info(commit, &info->reflogs, 0);
224         struct commit_reflog *commit_reflog;
225         struct object *logobj;
226         struct reflog_info *reflog;
227
228         info->last_commit_reflog = NULL;
229         if (!commit_info)
230                 return;
231
232         commit_reflog = commit_info->util;
233         if (commit_reflog->recno < 0) {
234                 commit->parents = NULL;
235                 return;
236         }
237         info->last_commit_reflog = commit_reflog;
238
239         do {
240                 reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
241                 commit_reflog->recno--;
242                 logobj = parse_object(reflog->osha1);
243         } while (commit_reflog->recno && (logobj && logobj->type != OBJ_COMMIT));
244
245         if (!logobj || logobj->type != OBJ_COMMIT) {
246                 commit_info->commit = NULL;
247                 commit->parents = NULL;
248                 return;
249         }
250         commit_info->commit = (struct commit *)logobj;
251
252         commit->parents = xcalloc(1, sizeof(struct commit_list));
253         commit->parents->item = commit_info->commit;
254 }
255
256 void get_reflog_selector(struct strbuf *sb,
257                          struct reflog_walk_info *reflog_info,
258                          const struct date_mode *dmode, int force_date,
259                          int shorten)
260 {
261         struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
262         struct reflog_info *info;
263         const char *printed_ref;
264
265         if (!commit_reflog)
266                 return;
267
268         if (shorten) {
269                 if (!commit_reflog->reflogs->short_ref)
270                         commit_reflog->reflogs->short_ref
271                                 = shorten_unambiguous_ref(commit_reflog->reflogs->ref, 0);
272                 printed_ref = commit_reflog->reflogs->short_ref;
273         } else {
274                 printed_ref = commit_reflog->reflogs->ref;
275         }
276
277         strbuf_addf(sb, "%s@{", printed_ref);
278         if (commit_reflog->selector == SELECTOR_DATE ||
279             (commit_reflog->selector == SELECTOR_NONE && force_date)) {
280                 info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
281                 strbuf_addstr(sb, show_date(info->timestamp, info->tz, dmode));
282         } else {
283                 strbuf_addf(sb, "%d", commit_reflog->reflogs->nr
284                             - 2 - commit_reflog->recno);
285         }
286
287         strbuf_addch(sb, '}');
288 }
289
290 void get_reflog_message(struct strbuf *sb,
291                         struct reflog_walk_info *reflog_info)
292 {
293         struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
294         struct reflog_info *info;
295         size_t len;
296
297         if (!commit_reflog)
298                 return;
299
300         info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
301         len = strlen(info->message);
302         if (len > 0)
303                 len--; /* strip away trailing newline */
304         strbuf_add(sb, info->message, len);
305 }
306
307 const char *get_reflog_ident(struct reflog_walk_info *reflog_info)
308 {
309         struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
310         struct reflog_info *info;
311
312         if (!commit_reflog)
313                 return NULL;
314
315         info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
316         return info->email;
317 }
318
319 void show_reflog_message(struct reflog_walk_info *reflog_info, int oneline,
320                          const struct date_mode *dmode, int force_date)
321 {
322         if (reflog_info && reflog_info->last_commit_reflog) {
323                 struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
324                 struct reflog_info *info;
325                 struct strbuf selector = STRBUF_INIT;
326
327                 info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
328                 get_reflog_selector(&selector, reflog_info, dmode, force_date, 0);
329                 if (oneline) {
330                         printf("%s: %s", selector.buf, info->message);
331                 }
332                 else {
333                         printf("Reflog: %s (%s)\nReflog message: %s",
334                                selector.buf, info->email, info->message);
335                 }
336
337                 strbuf_release(&selector);
338         }
339 }