diff options
Diffstat (limited to 'unpack-trees.c')
| -rw-r--r-- | unpack-trees.c | 1841 |
1 files changed, 1841 insertions, 0 deletions
diff --git a/unpack-trees.c b/unpack-trees.c new file mode 100644 index 0000000000..ede4299b83 --- /dev/null +++ b/unpack-trees.c @@ -0,0 +1,1841 @@ +#define NO_THE_INDEX_COMPATIBILITY_MACROS +#include "cache.h" +#include "dir.h" +#include "tree.h" +#include "tree-walk.h" +#include "cache-tree.h" +#include "unpack-trees.h" +#include "progress.h" +#include "refs.h" +#include "attr.h" + +/* + * Error messages expected by scripts out of plumbing commands such as + * read-tree. Non-scripted Porcelain is not required to use these messages + * and in fact are encouraged to reword them to better suit their particular + * situation better. See how "git checkout" and "git merge" replaces + * them using setup_unpack_trees_porcelain(), for example. + */ +static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = { + /* ERROR_WOULD_OVERWRITE */ + "Entry '%s' would be overwritten by merge. Cannot merge.", + + /* ERROR_NOT_UPTODATE_FILE */ + "Entry '%s' not uptodate. Cannot merge.", + + /* ERROR_NOT_UPTODATE_DIR */ + "Updating '%s' would lose untracked files in it", + + /* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */ + "Untracked working tree file '%s' would be overwritten by merge.", + + /* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */ + "Untracked working tree file '%s' would be removed by merge.", + + /* ERROR_BIND_OVERLAP */ + "Entry '%s' overlaps with '%s'. Cannot bind.", + + /* ERROR_SPARSE_NOT_UPTODATE_FILE */ + "Entry '%s' not uptodate. Cannot update sparse checkout.", + + /* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */ + "Working tree file '%s' would be overwritten by sparse checkout update.", + + /* ERROR_WOULD_LOSE_ORPHANED_REMOVED */ + "Working tree file '%s' would be removed by sparse checkout update.", +}; + +#define ERRORMSG(o,type) \ + ( ((o) && (o)->msgs[(type)]) \ + ? ((o)->msgs[(type)]) \ + : (unpack_plumbing_errors[(type)]) ) + +void setup_unpack_trees_porcelain(struct unpack_trees_options *opts, + const char *cmd) +{ + int i; + const char **msgs = opts->msgs; + const char *msg; + char *tmp; + const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches"; + if (advice_commit_before_merge) + msg = "Your local changes to the following files would be overwritten by %s:\n%%s" + "Please, commit your changes or stash them before you can %s."; + else + msg = "Your local changes to the following files would be overwritten by %s:\n%%s"; + tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2); + sprintf(tmp, msg, cmd, cmd2); + msgs[ERROR_WOULD_OVERWRITE] = tmp; + msgs[ERROR_NOT_UPTODATE_FILE] = tmp; + + msgs[ERROR_NOT_UPTODATE_DIR] = + "Updating the following directories would lose untracked files in it:\n%s"; + + if (advice_commit_before_merge) + msg = "The following untracked working tree files would be %s by %s:\n%%s" + "Please move or remove them before you can %s."; + else + msg = "The following untracked working tree files would be %s by %s:\n%%s"; + tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4); + sprintf(tmp, msg, "removed", cmd, cmd2); + msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp; + tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4); + sprintf(tmp, msg, "overwritten", cmd, cmd2); + msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp; + + /* + * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we + * cannot easily display it as a list. + */ + msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'. Cannot bind."; + + msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] = + "Cannot update sparse checkout: the following entries are not up-to-date:\n%s"; + msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] = + "The following Working tree files would be overwritten by sparse checkout update:\n%s"; + msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] = + "The following Working tree files would be removed by sparse checkout update:\n%s"; + + opts->show_all_errors = 1; + /* rejected paths may not have a static buffer */ + for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++) + opts->unpack_rejects[i].strdup_strings = 1; +} + +static void do_add_entry(struct unpack_trees_options *o, struct cache_entry *ce, + unsigned int set, unsigned int clear) +{ + clear |= CE_HASHED | CE_UNHASHED; + + if (set & CE_REMOVE) + set |= CE_WT_REMOVE; + + ce->next = NULL; + ce->ce_flags = (ce->ce_flags & ~clear) | set; + add_index_entry(&o->result, ce, + ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE); +} + +static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce, + unsigned int set, unsigned int clear) +{ + unsigned int size = ce_size(ce); + struct cache_entry *new = xmalloc(size); + + memcpy(new, ce, size); + do_add_entry(o, new, set, clear); +} + +/* + * add error messages on path <path> + * corresponding to the type <e> with the message <msg> + * indicating if it should be display in porcelain or not + */ +static int add_rejected_path(struct unpack_trees_options *o, + enum unpack_trees_error_types e, + const char *path) +{ + if (!o->show_all_errors) + return error(ERRORMSG(o, e), path); + + /* + * Otherwise, insert in a list for future display by + * display_error_msgs() + */ + string_list_append(&o->unpack_rejects[e], path); + return -1; +} + +/* + * display all the error messages stored in a nice way + */ +static void display_error_msgs(struct unpack_trees_options *o) +{ + int e, i; + int something_displayed = 0; + for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) { + struct string_list *rejects = &o->unpack_rejects[e]; + if (rejects->nr > 0) { + struct strbuf path = STRBUF_INIT; + something_displayed = 1; + for (i = 0; i < rejects->nr; i++) + strbuf_addf(&path, "\t%s\n", rejects->items[i].string); + error(ERRORMSG(o, e), path.buf); + strbuf_release(&path); + } + string_list_clear(rejects, 0); + } + if (something_displayed) + fprintf(stderr, "Aborting\n"); +} + +/* + * Unlink the last component and schedule the leading directories for + * removal, such that empty directories get removed. + */ +static void unlink_entry(struct cache_entry *ce) +{ + if (!check_leading_path(ce->name, ce_namelen(ce))) + return; + if (remove_or_warn(ce->ce_mode, ce->name)) + return; + schedule_dir_for_removal(ce->name, ce_namelen(ce)); +} + +static struct checkout state; +static int check_updates(struct unpack_trees_options *o) +{ + unsigned cnt = 0, total = 0; + struct progress *progress = NULL; + struct index_state *index = &o->result; + int i; + int errs = 0; + + if (o->update && o->verbose_update) { + for (total = cnt = 0; cnt < index->cache_nr; cnt++) { + struct cache_entry *ce = index->cache[cnt]; + if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE)) + total++; + } + + progress = start_progress_delay("Checking out files", + total, 50, 1); + cnt = 0; + } + + if (o->update) + git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result); + for (i = 0; i < index->cache_nr; i++) { + struct cache_entry *ce = index->cache[i]; + + if (ce->ce_flags & CE_WT_REMOVE) { + display_progress(progress, ++cnt); + if (o->update && !o->dry_run) + unlink_entry(ce); + continue; + } + } + remove_marked_cache_entries(&o->result); + remove_scheduled_dirs(); + + for (i = 0; i < index->cache_nr; i++) { + struct cache_entry *ce = index->cache[i]; + + if (ce->ce_flags & CE_UPDATE) { + display_progress(progress, ++cnt); + ce->ce_flags &= ~CE_UPDATE; + if (o->update && !o->dry_run) { + errs |= checkout_entry(ce, &state, NULL); + } + } + } + stop_progress(&progress); + if (o->update) + git_attr_set_direction(GIT_ATTR_CHECKIN, NULL); + return errs != 0; +} + +static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o); +static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o); + +static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_options *o) +{ + int was_skip_worktree = ce_skip_worktree(ce); + + if (ce->ce_flags & CE_NEW_SKIP_WORKTREE) + ce->ce_flags |= CE_SKIP_WORKTREE; + else + ce->ce_flags &= ~CE_SKIP_WORKTREE; + + /* + * if (!was_skip_worktree && !ce_skip_worktree()) { + * This is perfectly normal. Move on; + * } + */ + + /* + * Merge strategies may set CE_UPDATE|CE_REMOVE outside checkout + * area as a result of ce_skip_worktree() shortcuts in + * verify_absent() and verify_uptodate(). + * Make sure they don't modify worktree if they are already + * outside checkout area + */ + if (was_skip_worktree && ce_skip_worktree(ce)) { + ce->ce_flags &= ~CE_UPDATE; + + /* + * By default, when CE_REMOVE is on, CE_WT_REMOVE is also + * on to get that file removed from both index and worktree. + * If that file is already outside worktree area, don't + * bother remove it. + */ + if (ce->ce_flags & CE_REMOVE) + ce->ce_flags &= ~CE_WT_REMOVE; + } + + if (!was_skip_worktree && ce_skip_worktree(ce)) { + /* + * If CE_UPDATE is set, verify_uptodate() must be called already + * also stat info may have lost after merged_entry() so calling + * verify_uptodate() again may fail + */ + if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o)) + return -1; + ce->ce_flags |= CE_WT_REMOVE; + } + if (was_skip_worktree && !ce_skip_worktree(ce)) { + if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) + return -1; + ce->ce_flags |= CE_UPDATE; + } + return 0; +} + +static inline int call_unpack_fn(struct cache_entry **src, struct unpack_trees_options *o) +{ + int ret = o->fn(src, o); + if (ret > 0) + ret = 0; + return ret; +} + +static void mark_ce_used(struct cache_entry *ce, struct unpack_trees_options *o) +{ + ce->ce_flags |= CE_UNPACKED; + + if (o->cache_bottom < o->src_index->cache_nr && + o->src_index->cache[o->cache_bottom] == ce) { + int bottom = o->cache_bottom; + while (bottom < o->src_index->cache_nr && + o->src_index->cache[bottom]->ce_flags & CE_UNPACKED) + bottom++; + o->cache_bottom = bottom; + } +} + +static void mark_all_ce_unused(struct index_state *index) +{ + int i; + for (i = 0; i < index->cache_nr; i++) + index->cache[i]->ce_flags &= ~(CE_UNPACKED | CE_ADDED | CE_NEW_SKIP_WORKTREE); +} + +static int locate_in_src_index(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + struct index_state *index = o->src_index; + int len = ce_namelen(ce); + int pos = index_name_pos(index, ce->name, len); + if (pos < 0) + pos = -1 - pos; + return pos; +} + +/* + * We call unpack_index_entry() with an unmerged cache entry + * only in diff-index, and it wants a single callback. Skip + * the other unmerged entry with the same name. + */ +static void mark_ce_used_same_name(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + struct index_state *index = o->src_index; + int len = ce_namelen(ce); + int pos; + + for (pos = locate_in_src_index(ce, o); pos < index->cache_nr; pos++) { + struct cache_entry *next = index->cache[pos]; + if (len != ce_namelen(next) || + memcmp(ce->name, next->name, len)) + break; + mark_ce_used(next, o); + } +} + +static struct cache_entry *next_cache_entry(struct unpack_trees_options *o) +{ + const struct index_state *index = o->src_index; + int pos = o->cache_bottom; + + while (pos < index->cache_nr) { + struct cache_entry *ce = index->cache[pos]; + if (!(ce->ce_flags & CE_UNPACKED)) + return ce; + pos++; + } + return NULL; +} + +static void add_same_unmerged(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + struct index_state *index = o->src_index; + int len = ce_namelen(ce); + int pos = index_name_pos(index, ce->name, len); + + if (0 <= pos) + die("programming error in a caller of mark_ce_used_same_name"); + for (pos = -pos - 1; pos < index->cache_nr; pos++) { + struct cache_entry *next = index->cache[pos]; + if (len != ce_namelen(next) || + memcmp(ce->name, next->name, len)) + break; + add_entry(o, next, 0, 0); + mark_ce_used(next, o); + } +} + +static int unpack_index_entry(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, }; + int ret; + + src[0] = ce; + + mark_ce_used(ce, o); + if (ce_stage(ce)) { + if (o->skip_unmerged) { + add_entry(o, ce, 0, 0); + return 0; + } + } + ret = call_unpack_fn(src, o); + if (ce_stage(ce)) + mark_ce_used_same_name(ce, o); + return ret; +} + +static int find_cache_pos(struct traverse_info *, const struct name_entry *); + +static void restore_cache_bottom(struct traverse_info *info, int bottom) +{ + struct unpack_trees_options *o = info->data; + + if (o->diff_index_cached) + return; + o->cache_bottom = bottom; +} + +static int switch_cache_bottom(struct traverse_info *info) +{ + struct unpack_trees_options *o = info->data; + int ret, pos; + + if (o->diff_index_cached) + return 0; + ret = o->cache_bottom; + pos = find_cache_pos(info->prev, &info->name); + + if (pos < -1) + o->cache_bottom = -2 - pos; + else if (pos < 0) + o->cache_bottom = o->src_index->cache_nr; + return ret; +} + +static int traverse_trees_recursive(int n, unsigned long dirmask, + unsigned long df_conflicts, + struct name_entry *names, + struct traverse_info *info) +{ + int i, ret, bottom; + struct tree_desc t[MAX_UNPACK_TREES]; + void *buf[MAX_UNPACK_TREES]; + struct traverse_info newinfo; + struct name_entry *p; + + p = names; + while (!p->mode) + p++; + + newinfo = *info; + newinfo.prev = info; + newinfo.pathspec = info->pathspec; + newinfo.name = *p; + newinfo.pathlen += tree_entry_len(p) + 1; + newinfo.conflicts |= df_conflicts; + + for (i = 0; i < n; i++, dirmask >>= 1) { + const unsigned char *sha1 = NULL; + if (dirmask & 1) + sha1 = names[i].sha1; + buf[i] = fill_tree_descriptor(t+i, sha1); + } + + bottom = switch_cache_bottom(&newinfo); + ret = traverse_trees(n, t, &newinfo); + restore_cache_bottom(&newinfo, bottom); + + for (i = 0; i < n; i++) + free(buf[i]); + + return ret; +} + +/* + * Compare the traverse-path to the cache entry without actually + * having to generate the textual representation of the traverse + * path. + * + * NOTE! This *only* compares up to the size of the traverse path + * itself - the caller needs to do the final check for the cache + * entry having more data at the end! + */ +static int do_compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n) +{ + int len, pathlen, ce_len; + const char *ce_name; + + if (info->prev) { + int cmp = do_compare_entry(ce, info->prev, &info->name); + if (cmp) + return cmp; + } + pathlen = info->pathlen; + ce_len = ce_namelen(ce); + + /* If ce_len < pathlen then we must have previously hit "name == directory" entry */ + if (ce_len < pathlen) + return -1; + + ce_len -= pathlen; + ce_name = ce->name + pathlen; + + len = tree_entry_len(n); + return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode); +} + +static int compare_entry(const struct cache_entry *ce, const struct traverse_info *info, const struct name_entry *n) +{ + int cmp = do_compare_entry(ce, info, n); + if (cmp) + return cmp; + + /* + * Even if the beginning compared identically, the ce should + * compare as bigger than a directory leading up to it! + */ + return ce_namelen(ce) > traverse_path_len(info, n); +} + +static int ce_in_traverse_path(const struct cache_entry *ce, + const struct traverse_info *info) +{ + if (!info->prev) + return 1; + if (do_compare_entry(ce, info->prev, &info->name)) + return 0; + /* + * If ce (blob) is the same name as the path (which is a tree + * we will be descending into), it won't be inside it. + */ + return (info->pathlen < ce_namelen(ce)); +} + +static struct cache_entry *create_ce_entry(const struct traverse_info *info, const struct name_entry *n, int stage) +{ + int len = traverse_path_len(info, n); + struct cache_entry *ce = xcalloc(1, cache_entry_size(len)); + + ce->ce_mode = create_ce_mode(n->mode); + ce->ce_flags = create_ce_flags(stage); + ce->ce_namelen = len; + hashcpy(ce->sha1, n->sha1); + make_traverse_path(ce->name, info, n); + + return ce; +} + +static int unpack_nondirectories(int n, unsigned long mask, + unsigned long dirmask, + struct cache_entry **src, + const struct name_entry *names, + const struct traverse_info *info) +{ + int i; + struct unpack_trees_options *o = info->data; + unsigned long conflicts; + + /* Do we have *only* directories? Nothing to do */ + if (mask == dirmask && !src[0]) + return 0; + + conflicts = info->conflicts; + if (o->merge) + conflicts >>= 1; + conflicts |= dirmask; + + /* + * Ok, we've filled in up to any potential index entry in src[0], + * now do the rest. + */ + for (i = 0; i < n; i++) { + int stage; + unsigned int bit = 1ul << i; + if (conflicts & bit) { + src[i + o->merge] = o->df_conflict_entry; + continue; + } + if (!(mask & bit)) + continue; + if (!o->merge) + stage = 0; + else if (i + 1 < o->head_idx) + stage = 1; + else if (i + 1 > o->head_idx) + stage = 3; + else + stage = 2; + src[i + o->merge] = create_ce_entry(info, names + i, stage); + } + + if (o->merge) + return call_unpack_fn(src, o); + + for (i = 0; i < n; i++) + if (src[i] && src[i] != o->df_conflict_entry) + do_add_entry(o, src[i], 0, 0); + return 0; +} + +static int unpack_failed(struct unpack_trees_options *o, const char *message) +{ + discard_index(&o->result); + if (!o->gently && !o->exiting_early) { + if (message) + return error("%s", message); + return -1; + } + return -1; +} + +/* NEEDSWORK: give this a better name and share with tree-walk.c */ +static int name_compare(const char *a, int a_len, + const char *b, int b_len) +{ + int len = (a_len < b_len) ? a_len : b_len; + int cmp = memcmp(a, b, len); + if (cmp) + return cmp; + return (a_len - b_len); +} + +/* + * The tree traversal is looking at name p. If we have a matching entry, + * return it. If name p is a directory in the index, do not return + * anything, as we will want to match it when the traversal descends into + * the directory. + */ +static int find_cache_pos(struct traverse_info *info, + const struct name_entry *p) +{ + int pos; + struct unpack_trees_options *o = info->data; + struct index_state *index = o->src_index; + int pfxlen = info->pathlen; + int p_len = tree_entry_len(p); + + for (pos = o->cache_bottom; pos < index->cache_nr; pos++) { + struct cache_entry *ce = index->cache[pos]; + const char *ce_name, *ce_slash; + int cmp, ce_len; + + if (ce->ce_flags & CE_UNPACKED) { + /* + * cache_bottom entry is already unpacked, so + * we can never match it; don't check it + * again. + */ + if (pos == o->cache_bottom) + ++o->cache_bottom; + continue; + } + if (!ce_in_traverse_path(ce, info)) + continue; + ce_name = ce->name + pfxlen; + ce_slash = strchr(ce_name, '/'); + if (ce_slash) + ce_len = ce_slash - ce_name; + else + ce_len = ce_namelen(ce) - pfxlen; + cmp = name_compare(p->path, p_len, ce_name, ce_len); + /* + * Exact match; if we have a directory we need to + * delay returning it. + */ + if (!cmp) + return ce_slash ? -2 - pos : pos; + if (0 < cmp) + continue; /* keep looking */ + /* + * ce_name sorts after p->path; could it be that we + * have files under p->path directory in the index? + * E.g. ce_name == "t-i", and p->path == "t"; we may + * have "t/a" in the index. + */ + if (p_len < ce_len && !memcmp(ce_name, p->path, p_len) && + ce_name[p_len] < '/') + continue; /* keep looking */ + break; + } + return -1; +} + +static struct cache_entry *find_cache_entry(struct traverse_info *info, + const struct name_entry *p) +{ + int pos = find_cache_pos(info, p); + struct unpack_trees_options *o = info->data; + + if (0 <= pos) + return o->src_index->cache[pos]; + else + return NULL; +} + +static void debug_path(struct traverse_info *info) +{ + if (info->prev) { + debug_path(info->prev); + if (*info->prev->name.path) + putchar('/'); + } + printf("%s", info->name.path); +} + +static void debug_name_entry(int i, struct name_entry *n) +{ + printf("ent#%d %06o %s\n", i, + n->path ? n->mode : 0, + n->path ? n->path : "(missing)"); +} + +static void debug_unpack_callback(int n, + unsigned long mask, + unsigned long dirmask, + struct name_entry *names, + struct traverse_info *info) +{ + int i; + printf("* unpack mask %lu, dirmask %lu, cnt %d ", + mask, dirmask, n); + debug_path(info); + putchar('\n'); + for (i = 0; i < n; i++) + debug_name_entry(i, names + i); +} + +static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info) +{ + struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, }; + struct unpack_trees_options *o = info->data; + const struct name_entry *p = names; + + /* Find first entry with a real name (we could use "mask" too) */ + while (!p->mode) + p++; + + if (o->debug_unpack) + debug_unpack_callback(n, mask, dirmask, names, info); + + /* Are we supposed to look at the index too? */ + if (o->merge) { + while (1) { + int cmp; + struct cache_entry *ce; + + if (o->diff_index_cached) + ce = next_cache_entry(o); + else + ce = find_cache_entry(info, p); + + if (!ce) + break; + cmp = compare_entry(ce, info, p); + if (cmp < 0) { + if (unpack_index_entry(ce, o) < 0) + return unpack_failed(o, NULL); + continue; + } + if (!cmp) { + if (ce_stage(ce)) { + /* + * If we skip unmerged index + * entries, we'll skip this + * entry *and* the tree + * entries associated with it! + */ + if (o->skip_unmerged) { + add_same_unmerged(ce, o); + return mask; + } + } + src[0] = ce; + } + break; + } + } + + if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0) + return -1; + + if (o->merge && src[0]) { + if (ce_stage(src[0])) + mark_ce_used_same_name(src[0], o); + else + mark_ce_used(src[0], o); + } + + /* Now handle any directories.. */ + if (dirmask) { + unsigned long conflicts = mask & ~dirmask; + if (o->merge) { + conflicts <<= 1; + if (src[0]) + conflicts |= 1; + } + + /* special case: "diff-index --cached" looking at a tree */ + if (o->diff_index_cached && + n == 1 && dirmask == 1 && S_ISDIR(names->mode)) { + int matches; + matches = cache_tree_matches_traversal(o->src_index->cache_tree, + names, info); + /* + * Everything under the name matches; skip the + * entire hierarchy. diff_index_cached codepath + * special cases D/F conflicts in such a way that + * it does not do any look-ahead, so this is safe. + */ + if (matches) { + o->cache_bottom += matches; + return mask; + } + } + + if (traverse_trees_recursive(n, dirmask, conflicts, + names, info) < 0) + return -1; + return mask; + } + + return mask; +} + +static int clear_ce_flags_1(struct cache_entry **cache, int nr, + char *prefix, int prefix_len, + int select_mask, int clear_mask, + struct exclude_list *el, int defval); + +/* Whole directory matching */ +static int clear_ce_flags_dir(struct cache_entry **cache, int nr, + char *prefix, int prefix_len, + char *basename, + int select_mask, int clear_mask, + struct exclude_list *el, int defval) +{ + struct cache_entry **cache_end; + int dtype = DT_DIR; + int ret = is_excluded_from_list(prefix, prefix_len, + basename, &dtype, el); + + prefix[prefix_len++] = '/'; + + /* If undecided, use matching result of parent dir in defval */ + if (ret < 0) + ret = defval; + + for (cache_end = cache; cache_end != cache + nr; cache_end++) { + struct cache_entry *ce = *cache_end; + if (strncmp(ce->name, prefix, prefix_len)) + break; + } + + /* + * TODO: check el, if there are no patterns that may conflict + * with ret (iow, we know in advance the incl/excl + * decision for the entire directory), clear flag here without + * calling clear_ce_flags_1(). That function will call + * the expensive is_excluded_from_list() on every entry. + */ + return clear_ce_flags_1(cache, cache_end - cache, + prefix, prefix_len, + select_mask, clear_mask, + el, ret); +} + +/* + * Traverse the index, find every entry that matches according to + * o->el. Do "ce_flags &= ~clear_mask" on those entries. Return the + * number of traversed entries. + * + * If select_mask is non-zero, only entries whose ce_flags has on of + * those bits enabled are traversed. + * + * cache : pointer to an index entry + * prefix_len : an offset to its path + * + * The current path ("prefix") including the trailing '/' is + * cache[0]->name[0..(prefix_len-1)] + * Top level path has prefix_len zero. + */ +static int clear_ce_flags_1(struct cache_entry **cache, int nr, + char *prefix, int prefix_len, + int select_mask, int clear_mask, + struct exclude_list *el, int defval) +{ + struct cache_entry **cache_end = cache + nr; + + /* + * Process all entries that have the given prefix and meet + * select_mask condition + */ + while(cache != cache_end) { + struct cache_entry *ce = *cache; + const char *name, *slash; + int len, dtype, ret; + + if (select_mask && !(ce->ce_flags & select_mask)) { + cache++; + continue; + } + + if (prefix_len && strncmp(ce->name, prefix, prefix_len)) + break; + + name = ce->name + prefix_len; + slash = strchr(name, '/'); + + /* If it's a directory, try whole directory match first */ + if (slash) { + int processed; + + len = slash - name; + memcpy(prefix + prefix_len, name, len); + + /* + * terminate the string (no trailing slash), + * clear_c_f_dir needs it + */ + prefix[prefix_len + len] = '\0'; + processed = clear_ce_flags_dir(cache, cache_end - cache, + prefix, prefix_len + len, + prefix + prefix_len, + select_mask, clear_mask, + el, defval); + + /* clear_c_f_dir eats a whole dir already? */ + if (processed) { + cache += processed; + continue; + } + + prefix[prefix_len + len++] = '/'; + cache += clear_ce_flags_1(cache, cache_end - cache, + prefix, prefix_len + len, + select_mask, clear_mask, el, defval); + continue; + } + + /* Non-directory */ + dtype = ce_to_dtype(ce); + ret = is_excluded_from_list(ce->name, ce_namelen(ce), + name, &dtype, el); + if (ret < 0) + ret = defval; + if (ret > 0) + ce->ce_flags &= ~clear_mask; + cache++; + } + return nr - (cache_end - cache); +} + +static int clear_ce_flags(struct cache_entry **cache, int nr, + int select_mask, int clear_mask, + struct exclude_list *el) +{ + char prefix[PATH_MAX]; + return clear_ce_flags_1(cache, nr, + prefix, 0, + select_mask, clear_mask, + el, 0); +} + +/* + * Set/Clear CE_NEW_SKIP_WORKTREE according to $GIT_DIR/info/sparse-checkout + */ +static void mark_new_skip_worktree(struct exclude_list *el, + struct index_state *the_index, + int select_flag, int skip_wt_flag) +{ + int i; + + /* + * 1. Pretend the narrowest worktree: only unmerged entries + * are checked out + */ + for (i = 0; i < the_index->cache_nr; i++) { + struct cache_entry *ce = the_index->cache[i]; + + if (select_flag && !(ce->ce_flags & select_flag)) + continue; + + if (!ce_stage(ce)) + ce->ce_flags |= skip_wt_flag; + else + ce->ce_flags &= ~skip_wt_flag; + } + + /* + * 2. Widen worktree according to sparse-checkout file. + * Matched entries will have skip_wt_flag cleared (i.e. "in") + */ + clear_ce_flags(the_index->cache, the_index->cache_nr, + select_flag, skip_wt_flag, el); +} + +static int verify_absent(struct cache_entry *, enum unpack_trees_error_types, struct unpack_trees_options *); +/* + * N-way merge "len" trees. Returns 0 on success, -1 on failure to manipulate the + * resulting index, -2 on failure to reflect the changes to the work tree. + * + * CE_ADDED, CE_UNPACKED and CE_NEW_SKIP_WORKTREE are used internally + */ +int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o) +{ + int i, ret; + static struct cache_entry *dfc; + struct exclude_list el; + + if (len > MAX_UNPACK_TREES) + die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES); + memset(&state, 0, sizeof(state)); + state.base_dir = ""; + state.force = 1; + state.quiet = 1; + state.refresh_cache = 1; + + memset(&el, 0, sizeof(el)); + if (!core_apply_sparse_checkout || !o->update) + o->skip_sparse_checkout = 1; + if (!o->skip_sparse_checkout) { + if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, &el, 0) < 0) + o->skip_sparse_checkout = 1; + else + o->el = ⪙ + } + + memset(&o->result, 0, sizeof(o->result)); + o->result.initialized = 1; + o->result.timestamp.sec = o->src_index->timestamp.sec; + o->result.timestamp.nsec = o->src_index->timestamp.nsec; + o->result.version = o->src_index->version; + o->merge_size = len; + mark_all_ce_unused(o->src_index); + + /* + * Sparse checkout loop #1: set NEW_SKIP_WORKTREE on existing entries + */ + if (!o->skip_sparse_checkout) + mark_new_skip_worktree(o->el, o->src_index, 0, CE_NEW_SKIP_WORKTREE); + + if (!dfc) + dfc = xcalloc(1, cache_entry_size(0)); + o->df_conflict_entry = dfc; + + if (len) { + const char *prefix = o->prefix ? o->prefix : ""; + struct traverse_info info; + + setup_traverse_info(&info, prefix); + info.fn = unpack_callback; + info.data = o; + info.show_all_errors = o->show_all_errors; + info.pathspec = o->pathspec; + + if (o->prefix) { + /* + * Unpack existing index entries that sort before the + * prefix the tree is spliced into. Note that o->merge + * is always true in this case. + */ + while (1) { + struct cache_entry *ce = next_cache_entry(o); + if (!ce) + break; + if (ce_in_traverse_path(ce, &info)) + break; + if (unpack_index_entry(ce, o) < 0) + goto return_failed; + } + } + + if (traverse_trees(len, t, &info) < 0) + goto return_failed; + } + + /* Any left-over entries in the index? */ + if (o->merge) { + while (1) { + struct cache_entry *ce = next_cache_entry(o); + if (!ce) + break; + if (unpack_index_entry(ce, o) < 0) + goto return_failed; + } + } + mark_all_ce_unused(o->src_index); + + if (o->trivial_merges_only && o->nontrivial_merge) { + ret = unpack_failed(o, "Merge requires file-level merging"); + goto done; + } + + if (!o->skip_sparse_checkout) { + int empty_worktree = 1; + + /* + * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1 + * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE + * so apply_sparse_checkout() won't attempt to remove it from worktree + */ + mark_new_skip_worktree(o->el, &o->result, CE_ADDED, CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE); + + ret = 0; + for (i = 0; i < o->result.cache_nr; i++) { + struct cache_entry *ce = o->result.cache[i]; + + /* + * Entries marked with CE_ADDED in merged_entry() do not have + * verify_absent() check (the check is effectively disabled + * because CE_NEW_SKIP_WORKTREE is set unconditionally). + * + * Do the real check now because we have had + * correct CE_NEW_SKIP_WORKTREE + */ + if (ce->ce_flags & CE_ADDED && + verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) { + if (!o->show_all_errors) + goto return_failed; + ret = -1; + } + + if (apply_sparse_checkout(ce, o)) { + if (!o->show_all_errors) + goto return_failed; + ret = -1; + } + if (!ce_skip_worktree(ce)) + empty_worktree = 0; + + } + if (ret < 0) + goto return_failed; + /* + * Sparse checkout is meant to narrow down checkout area + * but it does not make sense to narrow down to empty working + * tree. This is usually a mistake in sparse checkout rules. + * Do not allow users to do that. + */ + if (o->result.cache_nr && empty_worktree) { + ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory"); + goto done; + } + } + + o->src_index = NULL; + ret = check_updates(o) ? (-2) : 0; + if (o->dst_index) + *o->dst_index = o->result; + +done: + clear_exclude_list(&el); + return ret; + +return_failed: + if (o->show_all_errors) + display_error_msgs(o); + mark_all_ce_unused(o->src_index); + ret = unpack_failed(o, NULL); + if (o->exiting_early) + ret = 0; + goto done; +} + +/* Here come the merge functions */ + +static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o) +{ + return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name); +} + +static int same(struct cache_entry *a, struct cache_entry *b) +{ + if (!!a != !!b) + return 0; + if (!a && !b) + return 1; + if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED) + return 0; + return a->ce_mode == b->ce_mode && + !hashcmp(a->sha1, b->sha1); +} + + +/* + * When a CE gets turned into an unmerged entry, we + * want it to be up-to-date + */ +static int verify_uptodate_1(struct cache_entry *ce, + struct unpack_trees_options *o, + enum unpack_trees_error_types error_type) +{ + struct stat st; + + if (o->index_only) + return 0; + + /* + * CE_VALID and CE_SKIP_WORKTREE cheat, we better check again + * if this entry is truly up-to-date because this file may be + * overwritten. + */ + if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) + ; /* keep checking */ + else if (o->reset || ce_uptodate(ce)) + return 0; + + if (!lstat(ce->name, &st)) { + int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE; + unsigned changed = ie_match_stat(o->src_index, ce, &st, flags); + if (!changed) + return 0; + /* + * NEEDSWORK: the current default policy is to allow + * submodule to be out of sync wrt the superproject + * index. This needs to be tightened later for + * submodules that are marked to be automatically + * checked out. + */ + if (S_ISGITLINK(ce->ce_mode)) + return 0; + errno = 0; + } + if (errno == ENOENT) + return 0; + return o->gently ? -1 : + add_rejected_path(o, error_type, ce->name); +} + +static int verify_uptodate(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE)) + return 0; + return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE); +} + +static int verify_uptodate_sparse(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE); +} + +static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o) +{ + if (ce) + cache_tree_invalidate_path(o->src_index->cache_tree, ce->name); +} + +/* + * Check that checking out ce->sha1 in subdir ce->name is not + * going to overwrite any working files. + * + * Currently, git does not checkout subprojects during a superproject + * checkout, so it is not going to overwrite anything. + */ +static int verify_clean_submodule(struct cache_entry *ce, + enum unpack_trees_error_types error_type, + struct unpack_trees_options *o) +{ + return 0; +} + +static int verify_clean_subdirectory(struct cache_entry *ce, + enum unpack_trees_error_types error_type, + struct unpack_trees_options *o) +{ + /* + * we are about to extract "ce->name"; we would not want to lose + * anything in the existing directory there. + */ + int namelen; + int i; + struct dir_struct d; + char *pathbuf; + int cnt = 0; + unsigned char sha1[20]; + + if (S_ISGITLINK(ce->ce_mode) && + resolve_gitlink_ref(ce->name, "HEAD", sha1) == 0) { + /* If we are not going to update the submodule, then + * we don't care. + */ + if (!hashcmp(sha1, ce->sha1)) + return 0; + return verify_clean_submodule(ce, error_type, o); + } + + /* + * First let's make sure we do not have a local modification + * in that directory. + */ + namelen = ce_namelen(ce); + for (i = locate_in_src_index(ce, o); + i < o->src_index->cache_nr; + i++) { + struct cache_entry *ce2 = o->src_index->cache[i]; + int len = ce_namelen(ce2); + if (len < namelen || + strncmp(ce->name, ce2->name, namelen) || + ce2->name[namelen] != '/') + break; + /* + * ce2->name is an entry in the subdirectory to be + * removed. + */ + if (!ce_stage(ce2)) { + if (verify_uptodate(ce2, o)) + return -1; + add_entry(o, ce2, CE_REMOVE, 0); + mark_ce_used(ce2, o); + } + cnt++; + } + + /* + * Then we need to make sure that we do not lose a locally + * present file that is not ignored. + */ + pathbuf = xmalloc(namelen + 2); + memcpy(pathbuf, ce->name, namelen); + strcpy(pathbuf+namelen, "/"); + + memset(&d, 0, sizeof(d)); + if (o->dir) + d.exclude_per_dir = o->dir->exclude_per_dir; + i = read_directory(&d, pathbuf, namelen+1, NULL); + if (i) + return o->gently ? -1 : + add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name); + free(pathbuf); + return cnt; +} + +/* + * This gets called when there was no index entry for the tree entry 'dst', + * but we found a file in the working tree that 'lstat()' said was fine, + * and we're on a case-insensitive filesystem. + * + * See if we can find a case-insensitive match in the index that also + * matches the stat information, and assume it's that other file! + */ +static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st) +{ + struct cache_entry *src; + + src = index_name_exists(o->src_index, name, len, 1); + return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE); +} + +static int check_ok_to_remove(const char *name, int len, int dtype, + struct cache_entry *ce, struct stat *st, + enum unpack_trees_error_types error_type, + struct unpack_trees_options *o) +{ + struct cache_entry *result; + + /* + * It may be that the 'lstat()' succeeded even though + * target 'ce' was absent, because there is an old + * entry that is different only in case.. + * + * Ignore that lstat() if it matches. + */ + if (ignore_case && icase_exists(o, name, len, st)) + return 0; + + if (o->dir && + is_excluded(o->dir, name, &dtype)) + /* + * ce->name is explicitly excluded, so it is Ok to + * overwrite it. + */ + return 0; + if (S_ISDIR(st->st_mode)) { + /* + * We are checking out path "foo" and + * found "foo/." in the working tree. + * This is tricky -- if we have modified + * files that are in "foo/" we would lose + * them. + */ + if (verify_clean_subdirectory(ce, error_type, o) < 0) + return -1; + return 0; + } + + /* + * The previous round may already have decided to + * delete this path, which is in a subdirectory that + * is being replaced with a blob. + */ + result = index_name_exists(&o->result, name, len, 0); + if (result) { + if (result->ce_flags & CE_REMOVE) + return 0; + } + + return o->gently ? -1 : + add_rejected_path(o, error_type, name); +} + +/* + * We do not want to remove or overwrite a working tree file that + * is not tracked, unless it is ignored. + */ +static int verify_absent_1(struct cache_entry *ce, + enum unpack_trees_error_types error_type, + struct unpack_trees_options *o) +{ + int len; + struct stat st; + + if (o->index_only || o->reset || !o->update) + return 0; + + len = check_leading_path(ce->name, ce_namelen(ce)); + if (!len) + return 0; + else if (len > 0) { + char path[PATH_MAX + 1]; + memcpy(path, ce->name, len); + path[len] = 0; + if (lstat(path, &st)) + return error("cannot stat '%s': %s", path, + strerror(errno)); + + return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st, + error_type, o); + } else if (lstat(ce->name, &st)) { + if (errno != ENOENT) + return error("cannot stat '%s': %s", ce->name, + strerror(errno)); + return 0; + } else { + return check_ok_to_remove(ce->name, ce_namelen(ce), + ce_to_dtype(ce), ce, &st, + error_type, o); + } +} + +static int verify_absent(struct cache_entry *ce, + enum unpack_trees_error_types error_type, + struct unpack_trees_options *o) +{ + if (!o->skip_sparse_checkout && (ce->ce_flags & CE_NEW_SKIP_WORKTREE)) + return 0; + return verify_absent_1(ce, error_type, o); +} + +static int verify_absent_sparse(struct cache_entry *ce, + enum unpack_trees_error_types error_type, + struct unpack_trees_options *o) +{ + enum unpack_trees_error_types orphaned_error = error_type; + if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN) + orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN; + + return verify_absent_1(ce, orphaned_error, o); +} + +static int merged_entry(struct cache_entry *merge, struct cache_entry *old, + struct unpack_trees_options *o) +{ + int update = CE_UPDATE; + + if (!old) { + /* + * New index entries. In sparse checkout, the following + * verify_absent() will be delayed until after + * traverse_trees() finishes in unpack_trees(), then: + * + * - CE_NEW_SKIP_WORKTREE will be computed correctly + * - verify_absent() be called again, this time with + * correct CE_NEW_SKIP_WORKTREE + * + * verify_absent() call here does nothing in sparse + * checkout (i.e. o->skip_sparse_checkout == 0) + */ + update |= CE_ADDED; + merge->ce_flags |= CE_NEW_SKIP_WORKTREE; + + if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) + return -1; + invalidate_ce_path(merge, o); + } else if (!(old->ce_flags & CE_CONFLICTED)) { + /* + * See if we can re-use the old CE directly? + * That way we get the uptodate stat info. + * + * This also removes the UPDATE flag on a match; otherwise + * we will end up overwriting local changes in the work tree. + */ + if (same(old, merge)) { + copy_cache_entry(merge, old); + update = 0; + } else { + if (verify_uptodate(old, o)) + return -1; + /* Migrate old flags over */ + update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE); + invalidate_ce_path(old, o); + } + } else { + /* + * Previously unmerged entry left as an existence + * marker by read_index_unmerged(); + */ + invalidate_ce_path(old, o); + } + + add_entry(o, merge, update, CE_STAGEMASK); + return 1; +} + +static int deleted_entry(struct cache_entry *ce, struct cache_entry *old, + struct unpack_trees_options *o) +{ + /* Did it exist in the index? */ + if (!old) { + if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o)) + return -1; + return 0; + } + if (!(old->ce_flags & CE_CONFLICTED) && verify_uptodate(old, o)) + return -1; + add_entry(o, ce, CE_REMOVE, 0); + invalidate_ce_path(ce, o); + return 1; +} + +static int keep_entry(struct cache_entry *ce, struct unpack_trees_options *o) +{ + add_entry(o, ce, 0, 0); + return 1; +} + +#if DBRT_DEBUG +static void show_stage_entry(FILE *o, + const char *label, const struct cache_entry *ce) +{ + if (!ce) + fprintf(o, "%s (missing)\n", label); + else + fprintf(o, "%s%06o %s %d\t%s\n", + label, + ce->ce_mode, + sha1_to_hex(ce->sha1), + ce_stage(ce), + ce->name); +} +#endif + +int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o) +{ + struct cache_entry *index; + struct cache_entry *head; + struct cache_entry *remote = stages[o->head_idx + 1]; + int count; + int head_match = 0; + int remote_match = 0; + + int df_conflict_head = 0; + int df_conflict_remote = 0; + + int any_anc_missing = 0; + int no_anc_exists = 1; + int i; + + for (i = 1; i < o->head_idx; i++) { + if (!stages[i] || stages[i] == o->df_conflict_entry) + any_anc_missing = 1; + else + no_anc_exists = 0; + } + + index = stages[0]; + head = stages[o->head_idx]; + + if (head == o->df_conflict_entry) { + df_conflict_head = 1; + head = NULL; + } + + if (remote == o->df_conflict_entry) { + df_conflict_remote = 1; + remote = NULL; + } + + /* + * First, if there's a #16 situation, note that to prevent #13 + * and #14. + */ + if (!same(remote, head)) { + for (i = 1; i < o->head_idx; i++) { + if (same(stages[i], head)) { + head_match = i; + } + if (same(stages[i], remote)) { + remote_match = i; + } + } + } + + /* + * We start with cases where the index is allowed to match + * something other than the head: #14(ALT) and #2ALT, where it + * is permitted to match the result instead. + */ + /* #14, #14ALT, #2ALT */ + if (remote && !df_conflict_head && head_match && !remote_match) { + if (index && !same(index, remote) && !same(index, head)) + return o->gently ? -1 : reject_merge(index, o); + return merged_entry(remote, index, o); + } + /* + * If we have an entry in the index cache, then we want to + * make sure that it matches head. + */ + if (index && !same(index, head)) + return o->gently ? -1 : reject_merge(index, o); + + if (head) { + /* #5ALT, #15 */ + if (same(head, remote)) + return merged_entry(head, index, o); + /* #13, #3ALT */ + if (!df_conflict_remote && remote_match && !head_match) + return merged_entry(head, index, o); + } + + /* #1 */ + if (!head && !remote && any_anc_missing) + return 0; + + /* + * Under the "aggressive" rule, we resolve mostly trivial + * cases that we historically had git-merge-one-file resolve. + */ + if (o->aggressive) { + int head_deleted = !head; + int remote_deleted = !remote; + struct cache_entry *ce = NULL; + + if (index) + ce = index; + else if (head) + ce = head; + else if (remote) + ce = remote; + else { + for (i = 1; i < o->head_idx; i++) { + if (stages[i] && stages[i] != o->df_conflict_entry) { + ce = stages[i]; + break; + } + } + } + + /* + * Deleted in both. + * Deleted in one and unchanged in the other. + */ + if ((head_deleted && remote_deleted) || + (head_deleted && remote && remote_match) || + (remote_deleted && head && head_match)) { + if (index) + return deleted_entry(index, index, o); + if (ce && !head_deleted) { + if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o)) + return -1; + } + return 0; + } + /* + * Added in both, identically. + */ + if (no_anc_exists && head && remote && same(head, remote)) + return merged_entry(head, index, o); + + } + + /* Below are "no merge" cases, which require that the index be + * up-to-date to avoid the files getting overwritten with + * conflict resolution files. + */ + if (index) { + if (verify_uptodate(index, o)) + return -1; + } + + o->nontrivial_merge = 1; + + /* #2, #3, #4, #6, #7, #9, #10, #11. */ + count = 0; + if (!head_match || !remote_match) { + for (i = 1; i < o->head_idx; i++) { + if (stages[i] && stages[i] != o->df_conflict_entry) { + keep_entry(stages[i], o); + count++; + break; + } + } + } +#if DBRT_DEBUG + else { + fprintf(stderr, "read-tree: warning #16 detected\n"); + show_stage_entry(stderr, "head ", stages[head_match]); + show_stage_entry(stderr, "remote ", stages[remote_match]); + } +#endif + if (head) { count += keep_entry(head, o); } + if (remote) { count += keep_entry(remote, o); } + return count; +} + +/* + * Two-way merge. + * + * The rule is to "carry forward" what is in the index without losing + * information across a "fast-forward", favoring a successful merge + * over a merge failure when it makes sense. For details of the + * "carry forward" rule, please see <Documentation/git-read-tree.txt>. + * + */ +int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o) +{ + struct cache_entry *current = src[0]; + struct cache_entry *oldtree = src[1]; + struct cache_entry *newtree = src[2]; + + if (o->merge_size != 2) + return error("Cannot do a twoway merge of %d trees", + o->merge_size); + + if (oldtree == o->df_conflict_entry) + oldtree = NULL; + if (newtree == o->df_conflict_entry) + newtree = NULL; + + if (current) { + if ((!oldtree && !newtree) || /* 4 and 5 */ + (!oldtree && newtree && + same(current, newtree)) || /* 6 and 7 */ + (oldtree && newtree && + same(oldtree, newtree)) || /* 14 and 15 */ + (oldtree && newtree && + !same(oldtree, newtree) && /* 18 and 19 */ + same(current, newtree))) { + return keep_entry(current, o); + } + else if (oldtree && !newtree && same(current, oldtree)) { + /* 10 or 11 */ + return deleted_entry(oldtree, current, o); + } + else if (oldtree && newtree && + same(current, oldtree) && !same(current, newtree)) { + /* 20 or 21 */ + return merged_entry(newtree, current, o); + } + else { + /* all other failures */ + if (oldtree) + return o->gently ? -1 : reject_merge(oldtree, o); + if (current) + return o->gently ? -1 : reject_merge(current, o); + if (newtree) + return o->gently ? -1 : reject_merge(newtree, o); + return -1; + } + } + else if (newtree) { + if (oldtree && !o->initial_checkout) { + /* + * deletion of the path was staged; + */ + if (same(oldtree, newtree)) + return 1; + return reject_merge(oldtree, o); + } + return merged_entry(newtree, current, o); + } + return deleted_entry(oldtree, current, o); +} + +/* + * Bind merge. + * + * Keep the index entries at stage0, collapse stage1 but make sure + * stage0 does not have anything there. + */ +int bind_merge(struct cache_entry **src, + struct unpack_trees_options *o) +{ + struct cache_entry *old = src[0]; + struct cache_entry *a = src[1]; + + if (o->merge_size != 1) + return error("Cannot do a bind merge of %d trees", + o->merge_size); + if (a && old) + return o->gently ? -1 : + error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name); + if (!a) + return keep_entry(old, o); + else + return merged_entry(a, NULL, o); +} + +/* + * One-way merge. + * + * The rule is: + * - take the stat information from stage0, take the data from stage1 + */ +int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o) +{ + struct cache_entry *old = src[0]; + struct cache_entry *a = src[1]; + + if (o->merge_size != 1) + return error("Cannot do a oneway merge of %d trees", + o->merge_size); + + if (!a || a == o->df_conflict_entry) + return deleted_entry(old, old, o); + + if (old && same(old, a)) { + int update = 0; + if (o->reset && o->update && !ce_uptodate(old) && !ce_skip_worktree(old)) { + struct stat st; + if (lstat(old->name, &st) || + ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE)) + update |= CE_UPDATE; + } + add_entry(o, old, update, 0); + return 0; + } + return merged_entry(a, old, o); +} |