mirror of
https://github.com/git/git
synced 2024-10-06 00:29:28 +00:00
16da134b1f
Basically, the options are passed by a struct unpack_trees_options now. That's all. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>
653 lines
15 KiB
C
653 lines
15 KiB
C
/*
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* GIT - The information manager from hell
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*
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* Copyright (C) Linus Torvalds, 2005
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*/
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#define DBRT_DEBUG 1
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#include "cache.h"
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#include "object.h"
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#include "tree.h"
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#include "tree-walk.h"
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#include "cache-tree.h"
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#include "unpack-trees.h"
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#include "builtin.h"
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static struct object_list *trees = NULL;
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static void reject_merge(struct cache_entry *ce)
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{
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die("Entry '%s' would be overwritten by merge. Cannot merge.",
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ce->name);
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}
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static int list_tree(unsigned char *sha1)
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{
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struct tree *tree = parse_tree_indirect(sha1);
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if (!tree)
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return -1;
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object_list_append(&tree->object, &trees);
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return 0;
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}
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static int same(struct cache_entry *a, struct cache_entry *b)
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{
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if (!!a != !!b)
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return 0;
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if (!a && !b)
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return 1;
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return a->ce_mode == b->ce_mode &&
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!memcmp(a->sha1, b->sha1, 20);
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}
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/*
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* When a CE gets turned into an unmerged entry, we
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* want it to be up-to-date
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*/
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static void verify_uptodate(struct cache_entry *ce,
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struct unpack_trees_options *o)
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{
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struct stat st;
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if (o->index_only || o->reset)
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return;
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if (!lstat(ce->name, &st)) {
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unsigned changed = ce_match_stat(ce, &st, 1);
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if (!changed)
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return;
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errno = 0;
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}
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if (o->reset) {
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ce->ce_flags |= htons(CE_UPDATE);
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return;
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}
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if (errno == ENOENT)
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return;
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die("Entry '%s' not uptodate. Cannot merge.", ce->name);
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}
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static void invalidate_ce_path(struct cache_entry *ce)
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{
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if (ce)
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cache_tree_invalidate_path(active_cache_tree, ce->name);
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}
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/*
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* We do not want to remove or overwrite a working tree file that
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* is not tracked.
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*/
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static void verify_absent(const char *path, const char *action,
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struct unpack_trees_options *o)
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{
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struct stat st;
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if (o->index_only || o->reset || !o->update)
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return;
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if (!lstat(path, &st))
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die("Untracked working tree file '%s' "
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"would be %s by merge.", path, action);
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}
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static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
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struct unpack_trees_options *o)
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{
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merge->ce_flags |= htons(CE_UPDATE);
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if (old) {
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/*
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* See if we can re-use the old CE directly?
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* That way we get the uptodate stat info.
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*
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* This also removes the UPDATE flag on
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* a match.
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*/
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if (same(old, merge)) {
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*merge = *old;
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} else {
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verify_uptodate(old, o);
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invalidate_ce_path(old);
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}
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}
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else {
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verify_absent(merge->name, "overwritten", o);
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invalidate_ce_path(merge);
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}
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merge->ce_flags &= ~htons(CE_STAGEMASK);
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add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
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return 1;
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}
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static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
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struct unpack_trees_options *o)
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{
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if (old)
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verify_uptodate(old, o);
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else
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verify_absent(ce->name, "removed", o);
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ce->ce_mode = 0;
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add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
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invalidate_ce_path(ce);
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return 1;
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}
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static int keep_entry(struct cache_entry *ce)
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{
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add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
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return 1;
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}
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#if DBRT_DEBUG
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static void show_stage_entry(FILE *o,
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const char *label, const struct cache_entry *ce)
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{
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if (!ce)
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fprintf(o, "%s (missing)\n", label);
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else
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fprintf(o, "%s%06o %s %d\t%s\n",
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label,
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ntohl(ce->ce_mode),
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sha1_to_hex(ce->sha1),
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ce_stage(ce),
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ce->name);
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}
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#endif
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static int threeway_merge(struct cache_entry **stages,
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struct unpack_trees_options *o)
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{
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struct cache_entry *index;
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struct cache_entry *head;
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struct cache_entry *remote = stages[o->head_idx + 1];
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int count;
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int head_match = 0;
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int remote_match = 0;
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const char *path = NULL;
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int df_conflict_head = 0;
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int df_conflict_remote = 0;
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int any_anc_missing = 0;
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int no_anc_exists = 1;
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int i;
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for (i = 1; i < o->head_idx; i++) {
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if (!stages[i])
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any_anc_missing = 1;
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else {
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if (!path)
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path = stages[i]->name;
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no_anc_exists = 0;
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}
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}
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index = stages[0];
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head = stages[o->head_idx];
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if (head == &o->df_conflict_entry) {
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df_conflict_head = 1;
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head = NULL;
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}
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if (remote == &o->df_conflict_entry) {
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df_conflict_remote = 1;
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remote = NULL;
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}
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if (!path && index)
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path = index->name;
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if (!path && head)
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path = head->name;
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if (!path && remote)
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path = remote->name;
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/* First, if there's a #16 situation, note that to prevent #13
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* and #14.
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*/
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if (!same(remote, head)) {
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for (i = 1; i < o->head_idx; i++) {
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if (same(stages[i], head)) {
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head_match = i;
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}
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if (same(stages[i], remote)) {
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remote_match = i;
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}
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}
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}
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/* We start with cases where the index is allowed to match
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* something other than the head: #14(ALT) and #2ALT, where it
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* is permitted to match the result instead.
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*/
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/* #14, #14ALT, #2ALT */
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if (remote && !df_conflict_head && head_match && !remote_match) {
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if (index && !same(index, remote) && !same(index, head))
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reject_merge(index);
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return merged_entry(remote, index, o);
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}
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/*
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* If we have an entry in the index cache, then we want to
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* make sure that it matches head.
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*/
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if (index && !same(index, head)) {
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reject_merge(index);
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}
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if (head) {
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/* #5ALT, #15 */
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if (same(head, remote))
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return merged_entry(head, index, o);
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/* #13, #3ALT */
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if (!df_conflict_remote && remote_match && !head_match)
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return merged_entry(head, index, o);
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}
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/* #1 */
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if (!head && !remote && any_anc_missing)
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return 0;
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/* Under the new "aggressive" rule, we resolve mostly trivial
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* cases that we historically had git-merge-one-file resolve.
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*/
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if (o->aggressive) {
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int head_deleted = !head && !df_conflict_head;
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int remote_deleted = !remote && !df_conflict_remote;
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/*
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* Deleted in both.
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* Deleted in one and unchanged in the other.
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*/
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if ((head_deleted && remote_deleted) ||
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(head_deleted && remote && remote_match) ||
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(remote_deleted && head && head_match)) {
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if (index)
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return deleted_entry(index, index, o);
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else if (path)
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verify_absent(path, "removed", o);
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return 0;
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}
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/*
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* Added in both, identically.
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*/
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if (no_anc_exists && head && remote && same(head, remote))
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return merged_entry(head, index, o);
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}
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/* Below are "no merge" cases, which require that the index be
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* up-to-date to avoid the files getting overwritten with
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* conflict resolution files.
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*/
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if (index) {
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verify_uptodate(index, o);
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}
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else if (path)
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verify_absent(path, "overwritten", o);
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o->nontrivial_merge = 1;
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/* #2, #3, #4, #6, #7, #9, #11. */
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count = 0;
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if (!head_match || !remote_match) {
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for (i = 1; i < o->head_idx; i++) {
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if (stages[i]) {
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keep_entry(stages[i]);
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count++;
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break;
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}
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}
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}
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#if DBRT_DEBUG
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else {
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fprintf(stderr, "read-tree: warning #16 detected\n");
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show_stage_entry(stderr, "head ", stages[head_match]);
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show_stage_entry(stderr, "remote ", stages[remote_match]);
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}
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#endif
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if (head) { count += keep_entry(head); }
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if (remote) { count += keep_entry(remote); }
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return count;
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}
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/*
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* Two-way merge.
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*
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* The rule is to "carry forward" what is in the index without losing
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* information across a "fast forward", favoring a successful merge
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* over a merge failure when it makes sense. For details of the
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* "carry forward" rule, please see <Documentation/git-read-tree.txt>.
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*
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*/
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static int twoway_merge(struct cache_entry **src,
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struct unpack_trees_options *o)
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{
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struct cache_entry *current = src[0];
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struct cache_entry *oldtree = src[1], *newtree = src[2];
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if (o->merge_size != 2)
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return error("Cannot do a twoway merge of %d trees",
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o->merge_size);
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if (current) {
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if ((!oldtree && !newtree) || /* 4 and 5 */
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(!oldtree && newtree &&
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same(current, newtree)) || /* 6 and 7 */
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(oldtree && newtree &&
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same(oldtree, newtree)) || /* 14 and 15 */
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(oldtree && newtree &&
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!same(oldtree, newtree) && /* 18 and 19*/
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same(current, newtree))) {
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return keep_entry(current);
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}
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else if (oldtree && !newtree && same(current, oldtree)) {
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/* 10 or 11 */
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return deleted_entry(oldtree, current, o);
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}
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else if (oldtree && newtree &&
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same(current, oldtree) && !same(current, newtree)) {
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/* 20 or 21 */
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return merged_entry(newtree, current, o);
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}
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else {
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/* all other failures */
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if (oldtree)
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reject_merge(oldtree);
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if (current)
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reject_merge(current);
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if (newtree)
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reject_merge(newtree);
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return -1;
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}
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}
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else if (newtree)
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return merged_entry(newtree, current, o);
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else
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return deleted_entry(oldtree, current, o);
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}
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/*
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* Bind merge.
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*
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* Keep the index entries at stage0, collapse stage1 but make sure
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* stage0 does not have anything there.
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*/
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static int bind_merge(struct cache_entry **src,
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struct unpack_trees_options *o)
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{
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struct cache_entry *old = src[0];
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struct cache_entry *a = src[1];
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if (o->merge_size != 1)
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return error("Cannot do a bind merge of %d trees\n",
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o->merge_size);
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if (a && old)
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die("Entry '%s' overlaps. Cannot bind.", a->name);
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if (!a)
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return keep_entry(old);
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else
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return merged_entry(a, NULL, o);
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}
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/*
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* One-way merge.
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*
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* The rule is:
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* - take the stat information from stage0, take the data from stage1
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*/
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static int oneway_merge(struct cache_entry **src,
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struct unpack_trees_options *o)
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{
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struct cache_entry *old = src[0];
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struct cache_entry *a = src[1];
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if (o->merge_size != 1)
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return error("Cannot do a oneway merge of %d trees",
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o->merge_size);
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if (!a)
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return deleted_entry(old, old, o);
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if (old && same(old, a)) {
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if (o->reset) {
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struct stat st;
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if (lstat(old->name, &st) ||
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ce_match_stat(old, &st, 1))
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old->ce_flags |= htons(CE_UPDATE);
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}
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return keep_entry(old);
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}
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return merged_entry(a, old, o);
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}
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static int read_cache_unmerged(void)
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{
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int i;
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struct cache_entry **dst;
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struct cache_entry *last = NULL;
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read_cache();
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dst = active_cache;
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for (i = 0; i < active_nr; i++) {
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struct cache_entry *ce = active_cache[i];
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if (ce_stage(ce)) {
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if (last && !strcmp(ce->name, last->name))
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continue;
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invalidate_ce_path(ce);
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last = ce;
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ce->ce_mode = 0;
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ce->ce_flags &= ~htons(CE_STAGEMASK);
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}
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*dst++ = ce;
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}
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active_nr = dst - active_cache;
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return !!last;
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}
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static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
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{
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struct tree_desc desc;
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struct name_entry entry;
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int cnt;
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memcpy(it->sha1, tree->object.sha1, 20);
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desc.buf = tree->buffer;
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desc.size = tree->size;
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cnt = 0;
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while (tree_entry(&desc, &entry)) {
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if (!S_ISDIR(entry.mode))
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cnt++;
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else {
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struct cache_tree_sub *sub;
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struct tree *subtree = lookup_tree(entry.sha1);
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if (!subtree->object.parsed)
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parse_tree(subtree);
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sub = cache_tree_sub(it, entry.path);
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sub->cache_tree = cache_tree();
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prime_cache_tree_rec(sub->cache_tree, subtree);
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cnt += sub->cache_tree->entry_count;
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}
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}
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it->entry_count = cnt;
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}
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static void prime_cache_tree(void)
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{
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struct tree *tree = (struct tree *)trees->item;
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if (!tree)
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return;
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active_cache_tree = cache_tree();
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prime_cache_tree_rec(active_cache_tree, tree);
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}
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static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <sha1> [<sha2> [<sha3>]])";
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static struct lock_file lock_file;
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int cmd_read_tree(int argc, const char **argv, const char *prefix)
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{
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int i, newfd, stage = 0;
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unsigned char sha1[20];
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struct unpack_trees_options opts;
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memset(&opts, 0, sizeof(opts));
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opts.head_idx = -1;
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setup_git_directory();
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git_config(git_default_config);
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newfd = hold_lock_file_for_update(&lock_file, get_index_file());
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if (newfd < 0)
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die("unable to create new index file");
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git_config(git_default_config);
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for (i = 1; i < argc; i++) {
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const char *arg = argv[i];
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/* "-u" means "update", meaning that a merge will update
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* the working tree.
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*/
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if (!strcmp(arg, "-u")) {
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opts.update = 1;
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continue;
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}
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if (!strcmp(arg, "-v")) {
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opts.verbose_update = 1;
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continue;
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}
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/* "-i" means "index only", meaning that a merge will
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* not even look at the working tree.
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*/
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if (!strcmp(arg, "-i")) {
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opts.index_only = 1;
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continue;
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}
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/* "--prefix=<subdirectory>/" means keep the current index
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* entries and put the entries from the tree under the
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* given subdirectory.
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*/
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if (!strncmp(arg, "--prefix=", 9)) {
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if (stage || opts.merge || opts.prefix)
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usage(read_tree_usage);
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opts.prefix = arg + 9;
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opts.merge = 1;
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stage = 1;
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if (read_cache_unmerged())
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die("you need to resolve your current index first");
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continue;
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}
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/* This differs from "-m" in that we'll silently ignore
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* unmerged entries and overwrite working tree files that
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* correspond to them.
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*/
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if (!strcmp(arg, "--reset")) {
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if (stage || opts.merge || opts.prefix)
|
|
usage(read_tree_usage);
|
|
opts.reset = 1;
|
|
opts.merge = 1;
|
|
stage = 1;
|
|
read_cache_unmerged();
|
|
continue;
|
|
}
|
|
|
|
if (!strcmp(arg, "--trivial")) {
|
|
opts.trivial_merges_only = 1;
|
|
continue;
|
|
}
|
|
|
|
if (!strcmp(arg, "--aggressive")) {
|
|
opts.aggressive = 1;
|
|
continue;
|
|
}
|
|
|
|
/* "-m" stands for "merge", meaning we start in stage 1 */
|
|
if (!strcmp(arg, "-m")) {
|
|
if (stage || opts.merge || opts.prefix)
|
|
usage(read_tree_usage);
|
|
if (read_cache_unmerged())
|
|
die("you need to resolve your current index first");
|
|
stage = 1;
|
|
opts.merge = 1;
|
|
continue;
|
|
}
|
|
|
|
/* using -u and -i at the same time makes no sense */
|
|
if (1 < opts.index_only + opts.update)
|
|
usage(read_tree_usage);
|
|
|
|
if (get_sha1(arg, sha1))
|
|
die("Not a valid object name %s", arg);
|
|
if (list_tree(sha1) < 0)
|
|
die("failed to unpack tree object %s", arg);
|
|
stage++;
|
|
}
|
|
if ((opts.update||opts.index_only) && !opts.merge)
|
|
usage(read_tree_usage);
|
|
|
|
if (opts.prefix) {
|
|
int pfxlen = strlen(opts.prefix);
|
|
int pos;
|
|
if (opts.prefix[pfxlen-1] != '/')
|
|
die("prefix must end with /");
|
|
if (stage != 2)
|
|
die("binding merge takes only one tree");
|
|
pos = cache_name_pos(opts.prefix, pfxlen);
|
|
if (0 <= pos)
|
|
die("corrupt index file");
|
|
pos = -pos-1;
|
|
if (pos < active_nr &&
|
|
!strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
|
|
die("subdirectory '%s' already exists.", opts.prefix);
|
|
pos = cache_name_pos(opts.prefix, pfxlen-1);
|
|
if (0 <= pos)
|
|
die("file '%.*s' already exists.",
|
|
pfxlen-1, opts.prefix);
|
|
}
|
|
|
|
if (opts.merge) {
|
|
if (stage < 2)
|
|
die("just how do you expect me to merge %d trees?", stage-1);
|
|
switch (stage - 1) {
|
|
case 1:
|
|
opts.fn = opts.prefix ? bind_merge : oneway_merge;
|
|
break;
|
|
case 2:
|
|
opts.fn = twoway_merge;
|
|
break;
|
|
case 3:
|
|
default:
|
|
opts.fn = threeway_merge;
|
|
cache_tree_free(&active_cache_tree);
|
|
break;
|
|
}
|
|
|
|
if (stage - 1 >= 3)
|
|
opts.head_idx = stage - 2;
|
|
else
|
|
opts.head_idx = 1;
|
|
}
|
|
|
|
unpack_trees(trees, &opts);
|
|
|
|
/*
|
|
* When reading only one tree (either the most basic form,
|
|
* "-m ent" or "--reset ent" form), we can obtain a fully
|
|
* valid cache-tree because the index must match exactly
|
|
* what came from the tree.
|
|
*/
|
|
if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
|
|
cache_tree_free(&active_cache_tree);
|
|
prime_cache_tree();
|
|
}
|
|
|
|
if (write_cache(newfd, active_cache, active_nr) ||
|
|
close(newfd) || commit_lock_file(&lock_file))
|
|
die("unable to write new index file");
|
|
return 0;
|
|
}
|