diff options
Diffstat (limited to 'unpack-trees.c')
| -rw-r--r-- | unpack-trees.c | 1002 |
1 files changed, 1002 insertions, 0 deletions
diff --git a/unpack-trees.c b/unpack-trees.c new file mode 100644 index 0000000000..cba0aca062 --- /dev/null +++ b/unpack-trees.c @@ -0,0 +1,1002 @@ +#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" + +/* + * 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" replaces not_uptodate_file to + * explain why it does not allow switching between branches when you have + * local changes, for example. + */ +static struct unpack_trees_error_msgs unpack_plumbing_errors = { + /* would_overwrite */ + "Entry '%s' would be overwritten by merge. Cannot merge.", + + /* not_uptodate_file */ + "Entry '%s' not uptodate. Cannot merge.", + + /* not_uptodate_dir */ + "Updating '%s' would lose untracked files in it", + + /* would_lose_untracked */ + "Untracked working tree file '%s' would be %s by merge.", + + /* bind_overlap */ + "Entry '%s' overlaps with '%s'. Cannot bind.", +}; + +#define ERRORMSG(o,fld) \ + ( ((o) && (o)->msgs.fld) \ + ? ((o)->msgs.fld) \ + : (unpack_plumbing_errors.fld) ) + +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); + + clear |= CE_HASHED | CE_UNHASHED; + + memcpy(new, ce, size); + new->next = NULL; + new->ce_flags = (new->ce_flags & ~clear) | set; + add_index_entry(&o->result, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|ADD_CACHE_SKIP_DFCHECK); +} + +/* Unlink the last component and attempt to remove leading + * directories, in case this unlink is the removal of the + * last entry in the directory -- empty directories are removed. + */ +static void unlink_entry(struct cache_entry *ce) +{ + char *cp, *prev; + char *name = ce->name; + + if (has_symlink_leading_path(ce_namelen(ce), ce->name)) + return; + if (unlink(name)) + return; + prev = NULL; + while (1) { + int status; + cp = strrchr(name, '/'); + if (prev) + *prev = '/'; + if (!cp) + break; + + *cp = 0; + status = rmdir(name); + if (status) { + *cp = '/'; + break; + } + prev = cp; + } +} + +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_REMOVE)) + total++; + } + + progress = start_progress_delay("Checking out files", + total, 50, 1); + cnt = 0; + } + + for (i = 0; i < index->cache_nr; i++) { + struct cache_entry *ce = index->cache[i]; + + if (ce->ce_flags & CE_REMOVE) { + display_progress(progress, ++cnt); + if (o->update) + unlink_entry(ce); + remove_index_entry_at(&o->result, i); + i--; + continue; + } + } + + 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) { + errs |= checkout_entry(ce, &state, NULL); + } + } + } + stop_progress(&progress); + return errs != 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 int unpack_index_entry(struct cache_entry *ce, struct unpack_trees_options *o) +{ + struct cache_entry *src[5] = { ce, }; + + o->pos++; + if (ce_stage(ce)) { + if (o->skip_unmerged) { + add_entry(o, ce, 0, 0); + return 0; + } + } + return call_unpack_fn(src, o); +} + +int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info) +{ + int i; + struct tree_desc t[MAX_UNPACK_TREES]; + struct traverse_info newinfo; + struct name_entry *p; + + p = names; + while (!p->mode) + p++; + + newinfo = *info; + newinfo.prev = info; + newinfo.name = *p; + newinfo.pathlen += tree_entry_len(p->path, p->sha1) + 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; + fill_tree_descriptor(t+i, sha1); + } + return traverse_trees(n, t, &newinfo); +} + +/* + * 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->path, n->sha1); + 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 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(len, stage); + 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[5], + 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); + + n += o->merge; + for (i = 0; i < n; i++) + add_entry(o, src[i], 0, 0); + return 0; +} + +static int unpack_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *names, struct traverse_info *info) +{ + struct cache_entry *src[5] = { 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++; + + /* Are we supposed to look at the index too? */ + if (o->merge) { + while (o->pos < o->src_index->cache_nr) { + struct cache_entry *ce = o->src_index->cache[o->pos]; + int cmp = compare_entry(ce, info, p); + if (cmp < 0) { + if (unpack_index_entry(ce, o) < 0) + return -1; + continue; + } + if (!cmp) { + o->pos++; + 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_entry(o, ce, 0, 0); + return mask; + } + } + src[0] = ce; + } + break; + } + } + + if (unpack_nondirectories(n, mask, dirmask, src, names, info) < 0) + return -1; + + /* Now handle any directories.. */ + if (dirmask) { + unsigned long conflicts = mask & ~dirmask; + if (o->merge) { + conflicts <<= 1; + if (src[0]) + conflicts |= 1; + } + if (traverse_trees_recursive(n, dirmask, conflicts, + names, info) < 0) + return -1; + return mask; + } + + return mask; +} + +static int unpack_failed(struct unpack_trees_options *o, const char *message) +{ + discard_index(&o->result); + if (!o->gently) { + if (message) + return error(message); + return -1; + } + return -1; +} + +/* + * 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. + */ +int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o) +{ + int ret; + static struct cache_entry *dfc; + + 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(&o->result, 0, sizeof(o->result)); + if (o->src_index) + o->result.timestamp = o->src_index->timestamp; + o->merge_size = len; + + if (!dfc) + dfc = xcalloc(1, sizeof(struct cache_entry) + 1); + 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; + + if (traverse_trees(len, t, &info) < 0) + return unpack_failed(o, NULL); + } + + /* Any left-over entries in the index? */ + if (o->merge) { + while (o->pos < o->src_index->cache_nr) { + struct cache_entry *ce = o->src_index->cache[o->pos]; + if (unpack_index_entry(ce, o) < 0) + return unpack_failed(o, NULL); + } + } + + if (o->trivial_merges_only && o->nontrivial_merge) + return unpack_failed(o, "Merge requires file-level merging"); + + o->src_index = NULL; + ret = check_updates(o) ? (-2) : 0; + if (o->dst_index) + *o->dst_index = o->result; + return ret; +} + +/* Here come the merge functions */ + +static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o) +{ + return error(ERRORMSG(o, 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; + 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(struct cache_entry *ce, + struct unpack_trees_options *o) +{ + struct stat st; + + if (o->index_only || o->reset) + return 0; + + if (!lstat(ce->name, &st)) { + unsigned changed = ie_match_stat(o->src_index, ce, &st, CE_MATCH_IGNORE_VALID); + if (!changed) + return 0; + /* + * NEEDSWORK: the current default policy is to allow + * submodule to be out of sync wrt the supermodule + * 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 : + error(ERRORMSG(o, not_uptodate_file), ce->name); +} + +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, const char *action, + struct unpack_trees_options *o) +{ + return 0; +} + +static int verify_clean_subdirectory(struct cache_entry *ce, const char *action, + 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 pos, 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, action, o); + } + + /* + * First let's make sure we do not have a local modification + * in that directory. + */ + namelen = strlen(ce->name); + pos = index_name_pos(o->src_index, ce->name, namelen); + if (0 <= pos) + return cnt; /* we have it as nondirectory */ + pos = -pos - 1; + for (i = pos; i < o->src_index->cache_nr; i++) { + struct cache_entry *ce = o->src_index->cache[i]; + int len = ce_namelen(ce); + if (len < namelen || + strncmp(ce->name, ce->name, namelen) || + ce->name[namelen] != '/') + break; + /* + * ce->name is an entry in the subdirectory. + */ + if (!ce_stage(ce)) { + if (verify_uptodate(ce, o)) + return -1; + add_entry(o, ce, CE_REMOVE, 0); + } + 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, ce->name, pathbuf, namelen+1, NULL); + if (i) + return o->gently ? -1 : + error(ERRORMSG(o, 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, struct cache_entry *dst, struct stat *st) +{ + struct cache_entry *src; + + src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1); + return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID); +} + +/* + * We do not want to remove or overwrite a working tree file that + * is not tracked, unless it is ignored. + */ +static int verify_absent(struct cache_entry *ce, const char *action, + struct unpack_trees_options *o) +{ + struct stat st; + + if (o->index_only || o->reset || !o->update) + return 0; + + if (has_symlink_leading_path(ce_namelen(ce), ce->name)) + return 0; + + if (!lstat(ce->name, &st)) { + int cnt; + int dtype = ce_to_dtype(ce); + 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, ce, &st)) + return 0; + + if (o->dir && excluded(o->dir, ce->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 + * it. + */ + cnt = verify_clean_subdirectory(ce, action, o); + + /* + * If this removed entries from the index, + * what that means is: + * + * (1) the caller unpack_trees_rec() saw path/foo + * in the index, and it has not removed it because + * it thinks it is handling 'path' as blob with + * D/F conflict; + * (2) we will return "ok, we placed a merged entry + * in the index" which would cause o->pos to be + * incremented by one; + * (3) however, original o->pos now has 'path/foo' + * marked with "to be removed". + * + * We need to increment it by the number of + * deleted entries here. + */ + o->pos += cnt; + 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, ce->name, ce_namelen(ce), 0); + if (result) { + if (result->ce_flags & CE_REMOVE) + return 0; + } + + return o->gently ? -1 : + error(ERRORMSG(o, would_lose_untracked), ce->name, action); + } + return 0; +} + +static int merged_entry(struct cache_entry *merge, struct cache_entry *old, + struct unpack_trees_options *o) +{ + int update = CE_UPDATE; + + if (old) { + /* + * 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; + invalidate_ce_path(old, o); + } + } + else { + if (verify_absent(merge, "overwritten", o)) + return -1; + invalidate_ce_path(merge, 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, "removed", o)) + return -1; + return 0; + } + if (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 new "aggressive" rule, we resolve mostly trivial + * cases that we historically had git-merge-one-file resolve. + */ + if (o->aggressive) { + int head_deleted = !head && !df_conflict_head; + int remote_deleted = !remote && !df_conflict_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, "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) + 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\n", + o->merge_size); + if (a && old) + return o->gently ? -1 : + error(ERRORMSG(o, 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) + return deleted_entry(old, old, o); + + if (old && same(old, a)) { + int update = 0; + if (o->reset) { + struct stat st; + if (lstat(old->name, &st) || + ie_match_stat(o->src_index, old, &st, CE_MATCH_IGNORE_VALID)) + update |= CE_UPDATE; + } + add_entry(o, old, update, 0); + return 0; + } + return merged_entry(a, old, o); +} |