diff options
| -rw-r--r-- | Documentation/git-cat-file.txt | 99 | ||||
| -rw-r--r-- | builtin/cat-file.c | 51 | ||||
| -rw-r--r-- | cache.h | 20 | ||||
| -rw-r--r-- | sha1_name.c | 20 | ||||
| -rwxr-xr-x | t/t1006-cat-file.sh | 206 | ||||
| -rw-r--r-- | tree-walk.c | 206 | ||||
| -rw-r--r-- | tree-walk.h | 18 |
7 files changed, 601 insertions, 19 deletions
diff --git a/Documentation/git-cat-file.txt b/Documentation/git-cat-file.txt index 499ae7b98a..319ab4cb08 100644 --- a/Documentation/git-cat-file.txt +++ b/Documentation/git-cat-file.txt @@ -10,7 +10,7 @@ SYNOPSIS -------- [verse] 'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv ) <object> -'git cat-file' (--batch | --batch-check) < <list-of-objects> +'git cat-file' (--batch | --batch-check) [--follow-symlinks] < <list-of-objects> DESCRIPTION ----------- @@ -72,6 +72,62 @@ OPTIONS --allow-unknown-type:: Allow -s or -t to query broken/corrupt objects of unknown type. +--follow-symlinks:: + With --batch or --batch-check, follow symlinks inside the + repository when requesting objects with extended SHA-1 + expressions of the form tree-ish:path-in-tree. Instead of + providing output about the link itself, provide output about + the linked-to object. If a symlink points outside the + tree-ish (e.g. a link to /foo or a root-level link to ../foo), + the portion of the link which is outside the tree will be + printed. ++ +This option does not (currently) work correctly when an object in the +index is specified (e.g. `:link` instead of `HEAD:link`) rather than +one in the tree. ++ +This option cannot (currently) be used unless `--batch` or +`--batch-check` is used. ++ +For example, consider a git repository containing: ++ +-- + f: a file containing "hello\n" + link: a symlink to f + dir/link: a symlink to ../f + plink: a symlink to ../f + alink: a symlink to /etc/passwd +-- ++ +For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print ++ +-- + ce013625030ba8dba906f756967f9e9ca394464a blob 6 +-- ++ +And `echo HEAD:link | git cat-file --batch --follow-symlinks` would +print the same thing, as would `HEAD:dir/link`, as they both point at +`HEAD:f`. ++ +Without `--follow-symlinks`, these would print data about the symlink +itself. In the case of `HEAD:link`, you would see ++ +-- + 4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1 +-- ++ +Both `plink` and `alink` point outside the tree, so they would +respectively print: ++ +-- + symlink 4 + ../f + + symlink 11 + /etc/passwd +-- + + OUTPUT ------ If '-t' is specified, one of the <type>. @@ -151,6 +207,47 @@ the repository, then `cat-file` will ignore any custom format and print: <object> SP missing LF ------------ +If --follow-symlinks is used, and a symlink in the repository points +outside the repository, then `cat-file` will ignore any custom format +and print: + +------------ +symlink SP <size> LF +<symlink> LF +------------ + +The symlink will either be absolute (beginning with a /), or relative +to the tree root. For instance, if dir/link points to ../../foo, then +<symlink> will be ../foo. <size> is the size of the symlink in bytes. + +If --follow-symlinks is used, the following error messages will be +displayed: + +------------ +<object> SP missing LF +------------ +is printed when the initial symlink requested does not exist. + +------------ +dangling SP <size> LF +<object> LF +------------ +is printed when the initial symlink exists, but something that +it (transitive-of) points to does not. + +------------ +loop SP <size> LF +<object> LF +------------ +is printed for symlink loops (or any symlinks that +require more than 40 link resolutions to resolve). + +------------ +notdir SP <size> LF +<object> LF +------------ +is printed when, during symlink resolution, a file is used as a +directory name. CAVEATS ------- diff --git a/builtin/cat-file.c b/builtin/cat-file.c index ecb488822f..049a95f1f1 100644 --- a/builtin/cat-file.c +++ b/builtin/cat-file.c @@ -8,6 +8,7 @@ #include "parse-options.h" #include "userdiff.h" #include "streaming.h" +#include "tree-walk.h" static int cat_one_file(int opt, const char *exp_type, const char *obj_name, int unknown_type) @@ -233,6 +234,7 @@ static void print_object_or_die(int fd, struct expand_data *data) struct batch_options { int enabled; + int follow_symlinks; int print_contents; const char *format; }; @@ -241,12 +243,44 @@ static int batch_one_object(const char *obj_name, struct batch_options *opt, struct expand_data *data) { struct strbuf buf = STRBUF_INIT; + struct object_context ctx; + int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0; + enum follow_symlinks_result result; if (!obj_name) return 1; - if (get_sha1(obj_name, data->sha1)) { - printf("%s missing\n", obj_name); + result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx); + if (result != FOUND) { + switch (result) { + case MISSING_OBJECT: + printf("%s missing\n", obj_name); + break; + case DANGLING_SYMLINK: + printf("dangling %"PRIuMAX"\n%s\n", + (uintmax_t)strlen(obj_name), obj_name); + break; + case SYMLINK_LOOP: + printf("loop %"PRIuMAX"\n%s\n", + (uintmax_t)strlen(obj_name), obj_name); + break; + case NOT_DIR: + printf("notdir %"PRIuMAX"\n%s\n", + (uintmax_t)strlen(obj_name), obj_name); + break; + default: + die("BUG: unknown get_sha1_with_context result %d\n", + result); + break; + } + fflush(stdout); + return 0; + } + + if (ctx.mode == 0) { + printf("symlink %"PRIuMAX"\n%s\n", + (uintmax_t)ctx.symlink_path.len, + ctx.symlink_path.buf); fflush(stdout); return 0; } @@ -333,7 +367,7 @@ static int batch_objects(struct batch_options *opt) static const char * const cat_file_usage[] = { N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"), - N_("git cat-file (--batch | --batch-check) < <list-of-objects>"), + N_("git cat-file (--batch | --batch-check) [--follow-symlinks] < <list-of-objects>"), NULL }; @@ -351,9 +385,8 @@ static int batch_option_callback(const struct option *opt, { struct batch_options *bo = opt->value; - if (unset) { - memset(bo, 0, sizeof(*bo)); - return 0; + if (bo->enabled) { + return 1; } bo->enabled = 1; @@ -387,6 +420,8 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix) { OPTION_CALLBACK, 0, "batch-check", &batch, "format", N_("show info about objects fed from the standard input"), PARSE_OPT_OPTARG, batch_option_callback }, + OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks, + N_("follow in-tree symlinks (used with --batch or --batch-check)")), OPT_END() }; @@ -411,6 +446,10 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix) usage_with_options(cat_file_usage, options); } + if (batch.follow_symlinks && !batch.enabled) { + usage_with_options(cat_file_usage, options); + } + if (batch.enabled) return batch_objects(&batch); @@ -971,15 +971,21 @@ struct object_context { unsigned char tree[20]; char path[PATH_MAX]; unsigned mode; + /* + * symlink_path is only used by get_tree_entry_follow_symlinks, + * and only for symlinks that point outside the repository. + */ + struct strbuf symlink_path; }; -#define GET_SHA1_QUIETLY 01 -#define GET_SHA1_COMMIT 02 -#define GET_SHA1_COMMITTISH 04 -#define GET_SHA1_TREE 010 -#define GET_SHA1_TREEISH 020 -#define GET_SHA1_BLOB 040 -#define GET_SHA1_ONLY_TO_DIE 04000 +#define GET_SHA1_QUIETLY 01 +#define GET_SHA1_COMMIT 02 +#define GET_SHA1_COMMITTISH 04 +#define GET_SHA1_TREE 010 +#define GET_SHA1_TREEISH 020 +#define GET_SHA1_BLOB 040 +#define GET_SHA1_FOLLOW_SYMLINKS 0100 +#define GET_SHA1_ONLY_TO_DIE 04000 extern int get_sha1(const char *str, unsigned char *sha1); extern int get_sha1_commit(const char *str, unsigned char *sha1); diff --git a/sha1_name.c b/sha1_name.c index 6de8c87c8a..46218ba02c 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -1433,11 +1433,19 @@ static int get_sha1_with_context_1(const char *name, new_filename = resolve_relative_path(filename); if (new_filename) filename = new_filename; - ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode); - if (ret && only_to_die) { - diagnose_invalid_sha1_path(prefix, filename, - tree_sha1, - name, len); + if (flags & GET_SHA1_FOLLOW_SYMLINKS) { + ret = get_tree_entry_follow_symlinks(tree_sha1, + filename, sha1, &oc->symlink_path, + &oc->mode); + } else { + ret = get_tree_entry(tree_sha1, filename, + sha1, &oc->mode); + if (ret && only_to_die) { + diagnose_invalid_sha1_path(prefix, + filename, + tree_sha1, + name, len); + } } hashcpy(oc->tree, tree_sha1); strlcpy(oc->path, filename, sizeof(oc->path)); @@ -1468,5 +1476,7 @@ void maybe_die_on_misspelt_object_name(const char *name, const char *prefix) int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc) { + if (flags & GET_SHA1_FOLLOW_SYMLINKS && flags & GET_SHA1_ONLY_TO_DIE) + die("BUG: incompatible flags for get_sha1_with_context"); return get_sha1_with_context_1(str, flags, NULL, sha1, orc); } diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh index 4f225db9a7..93a4794930 100755 --- a/t/t1006-cat-file.sh +++ b/t/t1006-cat-file.sh @@ -201,6 +201,13 @@ do ' done +for opt in t s e p +do + test_expect_success "Passing -$opt with --follow-symlinks fails" ' + test_must_fail git cat-file --follow-symlinks -$opt $hello_sha1 + ' +done + test_expect_success "--batch-check for a non-existent named object" ' test "foobar42 missing foobar84 missing" = \ @@ -341,4 +348,203 @@ test_expect_success "Size of large broken object is correct when type is large" test_cmp expect actual ' +# Tests for git cat-file --follow-symlinks +test_expect_success 'prep for symlink tests' ' + echo_without_newline "$hello_content" >morx && + test_ln_s_add morx same-dir-link && + test_ln_s_add dir link-to-dir && + test_ln_s_add ../fleem out-of-repo-link && + test_ln_s_add .. out-of-repo-link-dir && + test_ln_s_add same-dir-link link-to-link && + test_ln_s_add nope broken-same-dir-link && + mkdir dir && + test_ln_s_add ../morx dir/parent-dir-link && + test_ln_s_add .. dir/link-dir && + test_ln_s_add ../../escape dir/out-of-repo-link && + test_ln_s_add ../.. dir/out-of-repo-link-dir && + test_ln_s_add nope dir/broken-link-in-dir && + mkdir dir/subdir && + test_ln_s_add ../../morx dir/subdir/grandparent-dir-link && + test_ln_s_add ../../../great-escape dir/subdir/out-of-repo-link && + test_ln_s_add ../../.. dir/subdir/out-of-repo-link-dir && + test_ln_s_add ../../../ dir/subdir/out-of-repo-link-dir-trailing && + test_ln_s_add ../parent-dir-link dir/subdir/parent-dir-link-to-link && + echo_without_newline "$hello_content" >dir/subdir/ind2 && + echo_without_newline "$hello_content" >dir/ind1 && + test_ln_s_add dir dirlink && + test_ln_s_add dir/subdir subdirlink && + test_ln_s_add subdir/ind2 dir/link-to-child && + test_ln_s_add dir/link-to-child link-to-down-link && + test_ln_s_add dir/.. up-down && + test_ln_s_add dir/../ up-down-trailing && + test_ln_s_add dir/../morx up-down-file && + test_ln_s_add dir/../../morx up-up-down-file && + test_ln_s_add subdirlink/../../morx up-two-down-file && + test_ln_s_add loop1 loop2 && + test_ln_s_add loop2 loop1 && + git add morx dir/subdir/ind2 dir/ind1 && + git commit -am "test" && + echo $hello_sha1 blob $hello_size >found +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for non-links' ' + echo HEAD:morx | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual && + echo HEAD:nope missing >expect && + echo HEAD:nope | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for in-repo, same-dir links' ' + echo HEAD:same-dir-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for in-repo, links to dirs' ' + echo HEAD:link-to-dir/ind1 | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for broken in-repo, same-dir links' ' + echo dangling 25 >expect && + echo HEAD:broken-same-dir-link >>expect && + echo HEAD:broken-same-dir-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for same-dir links-to-links' ' + echo HEAD:link-to-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for parent-dir links' ' + echo HEAD:dir/parent-dir-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual && + echo notdir 29 >expect && + echo HEAD:dir/parent-dir-link/nope >>expect && + echo HEAD:dir/parent-dir-link/nope | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for .. links' ' + echo dangling 22 >expect && + echo HEAD:dir/link-dir/nope >>expect && + echo HEAD:dir/link-dir/nope | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:dir/link-dir/morx | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual && + echo dangling 27 >expect && + echo HEAD:dir/broken-link-in-dir >>expect && + echo HEAD:dir/broken-link-in-dir | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for ../.. links' ' + echo notdir 41 >expect && + echo HEAD:dir/subdir/grandparent-dir-link/nope >>expect && + echo HEAD:dir/subdir/grandparent-dir-link/nope | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:dir/subdir/grandparent-dir-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual && + echo HEAD:dir/subdir/parent-dir-link-to-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for dir/ links' ' + echo dangling 17 >expect && + echo HEAD:dirlink/morx >>expect && + echo HEAD:dirlink/morx | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo $hello_sha1 blob $hello_size >expect && + echo HEAD:dirlink/ind1 | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for dir/subdir links' ' + echo dangling 20 >expect && + echo HEAD:subdirlink/morx >>expect && + echo HEAD:subdirlink/morx | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:subdirlink/ind2 | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for dir ->subdir links' ' + echo notdir 27 >expect && + echo HEAD:dir/link-to-child/morx >>expect && + echo HEAD:dir/link-to-child/morx | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:dir/link-to-child | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual && + echo HEAD:link-to-down-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for out-of-repo symlinks' ' + echo symlink 8 >expect && + echo ../fleem >>expect && + echo HEAD:out-of-repo-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo symlink 2 >expect && + echo .. >>expect && + echo HEAD:out-of-repo-link-dir | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for out-of-repo symlinks in dirs' ' + echo symlink 9 >expect && + echo ../escape >>expect && + echo HEAD:dir/out-of-repo-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo symlink 2 >expect && + echo .. >>expect && + echo HEAD:dir/out-of-repo-link-dir | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for out-of-repo symlinks in subdirs' ' + echo symlink 15 >expect && + echo ../great-escape >>expect && + echo HEAD:dir/subdir/out-of-repo-link | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo symlink 2 >expect && + echo .. >>expect && + echo HEAD:dir/subdir/out-of-repo-link-dir | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo symlink 3 >expect && + echo ../ >>expect && + echo HEAD:dir/subdir/out-of-repo-link-dir-trailing | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlinks works for symlinks with internal ..' ' + echo HEAD: | git cat-file --batch-check >expect && + echo HEAD:up-down | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:up-down-trailing | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:up-down-file | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual && + echo symlink 7 >expect && + echo ../morx >>expect && + echo HEAD:up-up-down-file | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual && + echo HEAD:up-two-down-file | git cat-file --batch-check --follow-symlinks >actual && + test_cmp found actual +' + +test_expect_success 'git cat-file --batch-check --follow-symlink breaks loops' ' + echo loop 10 >expect && + echo HEAD:loop1 >>expect && + echo HEAD:loop1 | git cat-file --batch-check --follow-symlinks >actual && + test_cmp expect actual +' + +test_expect_success 'git cat-file --batch --follow-symlink returns correct sha and mode' ' + echo HEAD:morx | git cat-file --batch >expect && + echo HEAD:morx | git cat-file --batch --follow-symlinks >actual && + test_cmp expect actual +' + test_done diff --git a/tree-walk.c b/tree-walk.c index 5dd9a71804..6dccd2d5dd 100644 --- a/tree-walk.c +++ b/tree-walk.c @@ -415,6 +415,12 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info) return error; } +struct dir_state { + void *tree; + unsigned long size; + unsigned char sha1[20]; +}; + static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode) { int namelen = strlen(name); @@ -478,6 +484,206 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch return retval; } +/* + * This is Linux's built-in max for the number of symlinks to follow. + * That limit, of course, does not affect git, but it's a reasonable + * choice. + */ +#define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40 + +/** + * Find a tree entry by following symlinks in tree_sha (which is + * assumed to be the root of the repository). In the event that a + * symlink points outside the repository (e.g. a link to /foo or a + * root-level link to ../foo), the portion of the link which is + * outside the repository will be returned in result_path, and *mode + * will be set to 0. It is assumed that result_path is uninitialized. + * If there are no symlinks, or the end result of the symlink chain + * points to an object inside the repository, result will be filled in + * with the sha1 of the found object, and *mode will hold the mode of + * the object. + * + * See the code for enum follow_symlink_result for a description of + * the return values. + */ +enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_sha1, const char *name, unsigned char *result, struct strbuf *result_path, unsigned *mode) +{ + int retval = MISSING_OBJECT; + struct dir_state *parents = NULL; + size_t parents_alloc = 0; + ssize_t parents_nr = 0; + unsigned char current_tree_sha1[20]; + struct strbuf namebuf = STRBUF_INIT; + struct tree_desc t; + int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS; + int i; + + init_tree_desc(&t, NULL, 0UL); + strbuf_init(result_path, 0); + strbuf_addstr(&namebuf, name); + hashcpy(current_tree_sha1, tree_sha1); + + while (1) { + int find_result; + char *first_slash; + char *remainder = NULL; + + if (!t.buffer) { + void *tree; + unsigned char root[20]; + unsigned long size; + tree = read_object_with_reference(current_tree_sha1, + tree_type, &size, + root); + if (!tree) + goto done; + + ALLOC_GROW(parents, parents_nr + 1, parents_alloc); + parents[parents_nr].tree = tree; + parents[parents_nr].size = size; + hashcpy(parents[parents_nr].sha1, root); + parents_nr++; + + if (namebuf.buf[0] == '\0') { + hashcpy(result, root); + retval = FOUND; + goto done; + } + + if (!size) + goto done; + + /* descend */ + init_tree_desc(&t, tree, size); + } + + /* Handle symlinks to e.g. a//b by removing leading slashes */ + while (namebuf.buf[0] == '/') { + strbuf_remove(&namebuf, 0, 1); + } + + /* Split namebuf into a first component and a remainder */ + if ((first_slash = strchr(namebuf.buf, '/'))) { + *first_slash = 0; + remainder = first_slash + 1; + } + + if (!strcmp(namebuf.buf, "..")) { + struct dir_state *parent; + /* + * We could end up with .. in the namebuf if it + * appears in a symlink. + */ + + if (parents_nr == 1) { + if (remainder) + *first_slash = '/'; + strbuf_add(result_path, namebuf.buf, + namebuf.len); + *mode = 0; + retval = FOUND; + goto done; + } + parent = &parents[parents_nr - 1]; + free(parent->tree); + parents_nr--; + parent = &parents[parents_nr - 1]; + init_tree_desc(&t, parent->tree, parent->size); + strbuf_remove(&namebuf, 0, remainder ? 3 : 2); + continue; + } + + /* We could end up here via a symlink to dir/.. */ + if (namebuf.buf[0] == '\0') { + hashcpy(result, parents[parents_nr - 1].sha1); + retval = FOUND; + goto done; + } + + /* Look up the first (or only) path component in the tree. */ + find_result = find_tree_entry(&t, namebuf.buf, + current_tree_sha1, mode); + if (find_result) { + goto done; + } + + if (S_ISDIR(*mode)) { + if (!remainder) { + hashcpy(result, current_tree_sha1); + retval = FOUND; + goto done; + } + /* Descend the tree */ + t.buffer = NULL; + strbuf_remove(&namebuf, 0, + 1 + first_slash - namebuf.buf); + } else if (S_ISREG(*mode)) { + if (!remainder) { + hashcpy(result, current_tree_sha1); + retval = FOUND; + } else { + retval = NOT_DIR; + } + goto done; + } else if (S_ISLNK(*mode)) { + /* Follow a symlink */ + unsigned long link_len; + size_t len; + char *contents, *contents_start; + struct dir_state *parent; + enum object_type type; + + if (follows_remaining-- == 0) { + /* Too many symlinks followed */ + retval = SYMLINK_LOOP; + goto done; + } + + /* + * At this point, we have followed at a least + * one symlink, so on error we need to report this. + */ + retval = DANGLING_SYMLINK; + + contents = read_sha1_file(current_tree_sha1, &type, + &link_len); + + if (!contents) + goto done; + + if (contents[0] == '/') { + strbuf_addstr(result_path, contents); + free(contents); + *mode = 0; + retval = FOUND; + goto done; + } + + if (remainder) + len = first_slash - namebuf.buf; + else + len = namebuf.len; + + contents_start = contents; + + parent = &parents[parents_nr - 1]; + init_tree_desc(&t, parent->tree, parent->size); + strbuf_splice(&namebuf, 0, len, + contents_start, link_len); + if (remainder) + namebuf.buf[link_len] = '/'; + free(contents); + } + } +done: + for (i = 0; i < parents_nr; i++) + free(parents[i].tree); + free(parents); + + strbuf_release(&namebuf); + return retval; +} + static int match_entry(const struct pathspec_item *item, const struct name_entry *entry, int pathlen, const char *match, int matchlen, diff --git a/tree-walk.h b/tree-walk.h index ae7fb3a824..3b2f7bf17d 100644 --- a/tree-walk.h +++ b/tree-walk.h @@ -40,6 +40,24 @@ struct traverse_info; typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *); int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info); +enum follow_symlinks_result { + FOUND = 0, /* This includes out-of-tree links */ + MISSING_OBJECT = -1, /* The initial symlink is missing */ + DANGLING_SYMLINK = -2, /* + * The initial symlink is there, but + * (transitively) points to a missing + * in-tree file + */ + SYMLINK_LOOP = -3, + NOT_DIR = -4, /* + * Somewhere along the symlink chain, a path is + * requested which contains a file as a + * non-final element. + */ +}; + +enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_sha1, const char *name, unsigned char *result, struct strbuf *result_path, unsigned *mode); + struct traverse_info { struct traverse_info *prev; struct name_entry name; |