builtin / show-ref.con commit branch: segfault fixes and validation (8efb889)
   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
   9static const char * const show_ref_usage[] = {
  10        N_("git show-ref [-q|--quiet] [--verify] [--head] [-d|--dereference] [-s|--hash[=<n>]] [--abbrev[=<n>]] [--tags] [--heads] [--] [pattern*] "),
  11        N_("git show-ref --exclude-existing[=pattern] < ref-list"),
  12        NULL
  13};
  14
  15static int deref_tags, show_head, tags_only, heads_only, found_match, verify,
  16           quiet, hash_only, abbrev, exclude_arg;
  17static const char **pattern;
  18static const char *exclude_existing_arg;
  19
  20static 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
  29static int show_ref(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
  30{
  31        const char *hex;
  32        unsigned char peeled[20];
  33
  34        if (tags_only || heads_only) {
  35                int match;
  36
  37                match = heads_only && !prefixcmp(refname, "refs/heads/");
  38                match |= tags_only && !prefixcmp(refname, "refs/tags/");
  39                if (!match)
  40                        return 0;
  41        }
  42        if (pattern) {
  43                int reflen = strlen(refname);
  44                const char **p = pattern, *m;
  45                while ((m = *p++) != NULL) {
  46                        int len = strlen(m);
  47                        if (len > reflen)
  48                                continue;
  49                        if (memcmp(m, refname + reflen - len, len))
  50                                continue;
  51                        if (len == reflen)
  52                                goto match;
  53                        /* "--verify" requires an exact match */
  54                        if (verify)
  55                                continue;
  56                        if (refname[reflen - len - 1] == '/')
  57                                goto match;
  58                }
  59                return 0;
  60        }
  61
  62match:
  63        found_match++;
  64
  65        /* This changes the semantics slightly that even under quiet we
  66         * detect and return error if the repository is corrupt and
  67         * ref points at a nonexistent object.
  68         */
  69        if (!has_sha1_file(sha1))
  70                die("git show-ref: bad ref %s (%s)", refname,
  71                    sha1_to_hex(sha1));
  72
  73        if (quiet)
  74                return 0;
  75
  76        show_one(refname, sha1);
  77
  78        if (!deref_tags)
  79                return 0;
  80
  81        if (!peel_ref(refname, peeled)) {
  82                hex = find_unique_abbrev(peeled, abbrev);
  83                printf("%s %s^{}\n", hex, refname);
  84        }
  85        return 0;
  86}
  87
  88static int add_existing(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
  89{
  90        struct string_list *list = (struct string_list *)cbdata;
  91        string_list_insert(list, refname);
  92        return 0;
  93}
  94
  95/*
  96 * read "^(?:<anything>\s)?<refname>(?:\^\{\})?$" from the standard input,
  97 * and
  98 * (1) strip "^{}" at the end of line if any;
  99 * (2) ignore if match is provided and does not head-match refname;
 100 * (3) warn if refname is not a well-formed refname and skip;
 101 * (4) ignore if refname is a ref that exists in the local repository;
 102 * (5) otherwise output the line.
 103 */
 104static int exclude_existing(const char *match)
 105{
 106        static struct string_list existing_refs = STRING_LIST_INIT_NODUP;
 107        char buf[1024];
 108        int matchlen = match ? strlen(match) : 0;
 109
 110        for_each_ref(add_existing, &existing_refs);
 111        while (fgets(buf, sizeof(buf), stdin)) {
 112                char *ref;
 113                int len = strlen(buf);
 114
 115                if (len > 0 && buf[len - 1] == '\n')
 116                        buf[--len] = '\0';
 117                if (3 <= len && !strcmp(buf + len - 3, "^{}")) {
 118                        len -= 3;
 119                        buf[len] = '\0';
 120                }
 121                for (ref = buf + len; buf < ref; ref--)
 122                        if (isspace(ref[-1]))
 123                                break;
 124                if (match) {
 125                        int reflen = buf + len - ref;
 126                        if (reflen < matchlen)
 127                                continue;
 128                        if (strncmp(ref, match, matchlen))
 129                                continue;
 130                }
 131                if (check_refname_format(ref, 0)) {
 132                        warning("ref '%s' ignored", ref);
 133                        continue;
 134                }
 135                if (!string_list_has_string(&existing_refs, ref)) {
 136                        printf("%s\n", buf);
 137                }
 138        }
 139        return 0;
 140}
 141
 142static int hash_callback(const struct option *opt, const char *arg, int unset)
 143{
 144        hash_only = 1;
 145        /* Use full length SHA1 if no argument */
 146        if (!arg)
 147                return 0;
 148        return parse_opt_abbrev_cb(opt, arg, unset);
 149}
 150
 151static int exclude_existing_callback(const struct option *opt, const char *arg,
 152                                     int unset)
 153{
 154        exclude_arg = 1;
 155        *(const char **)opt->value = arg;
 156        return 0;
 157}
 158
 159static int help_callback(const struct option *opt, const char *arg, int unset)
 160{
 161        return -1;
 162}
 163
 164static const struct option show_ref_options[] = {
 165        OPT_BOOLEAN(0, "tags", &tags_only, N_("only show tags (can be combined with heads)")),
 166        OPT_BOOLEAN(0, "heads", &heads_only, N_("only show heads (can be combined with tags)")),
 167        OPT_BOOLEAN(0, "verify", &verify, N_("stricter reference checking, "
 168                    "requires exact ref path")),
 169        { OPTION_BOOLEAN, 'h', NULL, &show_head, NULL,
 170          N_("show the HEAD reference"),
 171          PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
 172        OPT_BOOLEAN(0, "head", &show_head, N_("show the HEAD reference")),
 173        OPT_BOOLEAN('d', "dereference", &deref_tags,
 174                    N_("dereference tags into object IDs")),
 175        { OPTION_CALLBACK, 's', "hash", &abbrev, N_("n"),
 176          N_("only show SHA1 hash using <n> digits"),
 177          PARSE_OPT_OPTARG, &hash_callback },
 178        OPT__ABBREV(&abbrev),
 179        OPT__QUIET(&quiet,
 180                   N_("do not print results to stdout (useful with --verify)")),
 181        { OPTION_CALLBACK, 0, "exclude-existing", &exclude_existing_arg,
 182          N_("pattern"), N_("show refs from stdin that aren't in local repository"),
 183          PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback },
 184        { OPTION_CALLBACK, 0, "help-all", NULL, NULL, N_("show usage"),
 185          PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 186        OPT_END()
 187};
 188
 189int cmd_show_ref(int argc, const char **argv, const char *prefix)
 190{
 191        if (argc == 2 && !strcmp(argv[1], "-h"))
 192                usage_with_options(show_ref_usage, show_ref_options);
 193
 194        argc = parse_options(argc, argv, prefix, show_ref_options,
 195                             show_ref_usage, PARSE_OPT_NO_INTERNAL_HELP);
 196
 197        if (exclude_arg)
 198                return exclude_existing(exclude_existing_arg);
 199
 200        pattern = argv;
 201        if (!*pattern)
 202                pattern = NULL;
 203
 204        if (verify) {
 205                if (!pattern)
 206                        die("--verify requires a reference");
 207                while (*pattern) {
 208                        unsigned char sha1[20];
 209
 210                        if (!prefixcmp(*pattern, "refs/") &&
 211                            !read_ref(*pattern, sha1)) {
 212                                if (!quiet)
 213                                        show_one(*pattern, sha1);
 214                        }
 215                        else if (!quiet)
 216                                die("'%s' - not a valid ref", *pattern);
 217                        else
 218                                return 1;
 219                        pattern++;
 220                }
 221                return 0;
 222        }
 223
 224        if (show_head)
 225                head_ref(show_ref, NULL);
 226        for_each_ref(show_ref, NULL);
 227        if (!found_match) {
 228                if (verify && !quiet)
 229                        die("No match");
 230                return 1;
 231        }
 232        return 0;
 233}