quickfetch(): Prevent overflow of the rev-list command line
[git] / builtin-show-ref.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "refs.h"
4 #include "object.h"
5 #include "tag.h"
6 #include "string-list.h"
7 #include "parse-options.h"
8
9 static const char * const show_ref_usage[] = {
10         "git show-ref [-q|--quiet] [--verify] [-h|--head] [-d|--dereference] [-s|--hash[=<n>]] [--abbrev[=<n>]] [--tags] [--heads] [--] [pattern*] ",
11         "git show-ref --exclude-existing[=pattern] < ref-list",
12         NULL
13 };
14
15 static int deref_tags, show_head, tags_only, heads_only, found_match, verify,
16            quiet, hash_only, abbrev, exclude_arg;
17 static const char **pattern;
18 static const char *exclude_existing_arg;
19
20 static void show_one(const char *refname, const unsigned char *sha1)
21 {
22         const char *hex = find_unique_abbrev(sha1, abbrev);
23         if (hash_only)
24                 printf("%s\n", hex);
25         else
26                 printf("%s %s\n", hex, refname);
27 }
28
29 static int show_ref(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
30 {
31         struct object *obj;
32         const char *hex;
33         unsigned char peeled[20];
34
35         if (tags_only || heads_only) {
36                 int match;
37
38                 match = heads_only && !prefixcmp(refname, "refs/heads/");
39                 match |= tags_only && !prefixcmp(refname, "refs/tags/");
40                 if (!match)
41                         return 0;
42         }
43         if (pattern) {
44                 int reflen = strlen(refname);
45                 const char **p = pattern, *m;
46                 while ((m = *p++) != NULL) {
47                         int len = strlen(m);
48                         if (len > reflen)
49                                 continue;
50                         if (memcmp(m, refname + reflen - len, len))
51                                 continue;
52                         if (len == reflen)
53                                 goto match;
54                         /* "--verify" requires an exact match */
55                         if (verify)
56                                 continue;
57                         if (refname[reflen - len - 1] == '/')
58                                 goto match;
59                 }
60                 return 0;
61         }
62
63 match:
64         found_match++;
65
66         /* This changes the semantics slightly that even under quiet we
67          * detect and return error if the repository is corrupt and
68          * ref points at a nonexistent object.
69          */
70         if (!has_sha1_file(sha1))
71                 die("git show-ref: bad ref %s (%s)", refname,
72                     sha1_to_hex(sha1));
73
74         if (quiet)
75                 return 0;
76
77         show_one(refname, sha1);
78
79         if (!deref_tags)
80                 return 0;
81
82         if ((flag & REF_ISPACKED) && !peel_ref(refname, peeled)) {
83                 if (!is_null_sha1(peeled)) {
84                         hex = find_unique_abbrev(peeled, abbrev);
85                         printf("%s %s^{}\n", hex, refname);
86                 }
87         }
88         else {
89                 obj = parse_object(sha1);
90                 if (!obj)
91                         die("git show-ref: bad ref %s (%s)", refname,
92                             sha1_to_hex(sha1));
93                 if (obj->type == OBJ_TAG) {
94                         obj = deref_tag(obj, refname, 0);
95                         if (!obj)
96                                 die("git show-ref: bad tag at ref %s (%s)", refname,
97                                     sha1_to_hex(sha1));
98                         hex = find_unique_abbrev(obj->sha1, abbrev);
99                         printf("%s %s^{}\n", hex, refname);
100                 }
101         }
102         return 0;
103 }
104
105 static int add_existing(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
106 {
107         struct string_list *list = (struct string_list *)cbdata;
108         string_list_insert(refname, list);
109         return 0;
110 }
111
112 /*
113  * read "^(?:<anything>\s)?<refname>(?:\^\{\})?$" from the standard input,
114  * and
115  * (1) strip "^{}" at the end of line if any;
116  * (2) ignore if match is provided and does not head-match refname;
117  * (3) warn if refname is not a well-formed refname and skip;
118  * (4) ignore if refname is a ref that exists in the local repository;
119  * (5) otherwise output the line.
120  */
121 static int exclude_existing(const char *match)
122 {
123         static struct string_list existing_refs = { NULL, 0, 0, 0 };
124         char buf[1024];
125         int matchlen = match ? strlen(match) : 0;
126
127         for_each_ref(add_existing, &existing_refs);
128         while (fgets(buf, sizeof(buf), stdin)) {
129                 char *ref;
130                 int len = strlen(buf);
131
132                 if (len > 0 && buf[len - 1] == '\n')
133                         buf[--len] = '\0';
134                 if (3 <= len && !strcmp(buf + len - 3, "^{}")) {
135                         len -= 3;
136                         buf[len] = '\0';
137                 }
138                 for (ref = buf + len; buf < ref; ref--)
139                         if (isspace(ref[-1]))
140                                 break;
141                 if (match) {
142                         int reflen = buf + len - ref;
143                         if (reflen < matchlen)
144                                 continue;
145                         if (strncmp(ref, match, matchlen))
146                                 continue;
147                 }
148                 if (check_ref_format(ref)) {
149                         warning("ref '%s' ignored", ref);
150                         continue;
151                 }
152                 if (!string_list_has_string(&existing_refs, ref)) {
153                         printf("%s\n", buf);
154                 }
155         }
156         return 0;
157 }
158
159 static int hash_callback(const struct option *opt, const char *arg, int unset)
160 {
161         hash_only = 1;
162         /* Use full length SHA1 if no argument */
163         if (!arg)
164                 return 0;
165         return parse_opt_abbrev_cb(opt, arg, unset);
166 }
167
168 static int exclude_existing_callback(const struct option *opt, const char *arg,
169                                      int unset)
170 {
171         exclude_arg = 1;
172         *(const char **)opt->value = arg;
173         return 0;
174 }
175
176 static int help_callback(const struct option *opt, const char *arg, int unset)
177 {
178         return -1;
179 }
180
181 static const struct option show_ref_options[] = {
182         OPT_BOOLEAN(0, "tags", &tags_only, "only show tags (can be combined with heads)"),
183         OPT_BOOLEAN(0, "heads", &heads_only, "only show heads (can be combined with tags)"),
184         OPT_BOOLEAN(0, "verify", &verify, "stricter reference checking, "
185                     "requires exact ref path"),
186         OPT_BOOLEAN('h', "head", &show_head, "show the HEAD reference"),
187         OPT_BOOLEAN('d', "dereference", &deref_tags,
188                     "dereference tags into object IDs"),
189         { OPTION_CALLBACK, 's', "hash", &abbrev, "n",
190           "only show SHA1 hash using <n> digits",
191           PARSE_OPT_OPTARG, &hash_callback },
192         OPT__ABBREV(&abbrev),
193         OPT__QUIET(&quiet),
194         { OPTION_CALLBACK, 0, "exclude-existing", &exclude_existing_arg,
195           "pattern", "show refs from stdin that aren't in local repository",
196           PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback },
197         { OPTION_CALLBACK, 0, "help-all", NULL, NULL, "show usage",
198           PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
199         OPT_END()
200 };
201
202 int cmd_show_ref(int argc, const char **argv, const char *prefix)
203 {
204         argc = parse_options(argc, argv, prefix, show_ref_options,
205                              show_ref_usage, PARSE_OPT_NO_INTERNAL_HELP);
206
207         if (exclude_arg)
208                 return exclude_existing(exclude_existing_arg);
209
210         pattern = argv;
211         if (!*pattern)
212                 pattern = NULL;
213
214         if (verify) {
215                 if (!pattern)
216                         die("--verify requires a reference");
217                 while (*pattern) {
218                         unsigned char sha1[20];
219
220                         if (!prefixcmp(*pattern, "refs/") &&
221                             resolve_ref(*pattern, sha1, 1, NULL)) {
222                                 if (!quiet)
223                                         show_one(*pattern, sha1);
224                         }
225                         else if (!quiet)
226                                 die("'%s' - not a valid ref", *pattern);
227                         else
228                                 return 1;
229                         pattern++;
230                 }
231                 return 0;
232         }
233
234         if (show_head)
235                 head_ref(show_ref, NULL);
236         for_each_ref(show_ref, NULL);
237         if (!found_match) {
238                 if (verify && !quiet)
239                         die("No match");
240                 return 1;
241         }
242         return 0;
243 }