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-rw-r--r--Makefile4
-rw-r--r--builtin-read-tree.c861
-rw-r--r--unpack-trees.c799
-rw-r--r--unpack-trees.h35
4 files changed, 874 insertions, 825 deletions
diff --git a/Makefile b/Makefile
index 5f4bb8d8f8..a538710ed6 100644
--- a/Makefile
+++ b/Makefile
@@ -227,7 +227,7 @@ LIB_H = \
blob.h cache.h commit.h csum-file.h delta.h \
diff.h object.h pack.h pkt-line.h quote.h refs.h \
run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
- tree-walk.h log-tree.h dir.h path-list.h builtin.h
+ tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h
DIFF_OBJS = \
diff.o diff-lib.o diffcore-break.o diffcore-order.o \
@@ -242,7 +242,7 @@ LIB_OBJS = \
server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
tag.o tree.o usage.o config.o environment.o ctype.o copy.o \
fetch-clone.o revision.o pager.o tree-walk.o xdiff-interface.o \
- alloc.o merge-file.o path-list.o help.o $(DIFF_OBJS)
+ alloc.o merge-file.o path-list.o help.o unpack-trees.o $(DIFF_OBJS)
BUILTIN_OBJS = \
builtin-add.o \
diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 71a7026df4..8da8acbb0a 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -3,419 +3,17 @@
*
* Copyright (C) Linus Torvalds, 2005
*/
-#define DBRT_DEBUG 1
#include "cache.h"
-
#include "object.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
-#include <sys/time.h>
-#include <signal.h>
+#include "unpack-trees.h"
#include "builtin.h"
-static int reset = 0;
-static int merge = 0;
-static int update = 0;
-static int index_only = 0;
-static int nontrivial_merge = 0;
-static int trivial_merges_only = 0;
-static int aggressive = 0;
-static int verbose_update = 0;
-static volatile int progress_update = 0;
-static const char *prefix = NULL;
-
-static int head_idx = -1;
-static int merge_size = 0;
-
static struct object_list *trees = NULL;
-static struct cache_entry df_conflict_entry;
-
-struct tree_entry_list {
- struct tree_entry_list *next;
- unsigned directory : 1;
- unsigned executable : 1;
- unsigned symlink : 1;
- unsigned int mode;
- const char *name;
- const unsigned char *sha1;
-};
-
-static struct tree_entry_list df_conflict_list;
-
-typedef int (*merge_fn_t)(struct cache_entry **src);
-
-static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
-{
- struct tree_desc desc;
- struct name_entry one;
- struct tree_entry_list *ret = NULL;
- struct tree_entry_list **list_p = &ret;
-
- desc.buf = tree->buffer;
- desc.size = tree->size;
-
- while (tree_entry(&desc, &one)) {
- struct tree_entry_list *entry;
-
- entry = xmalloc(sizeof(struct tree_entry_list));
- entry->name = one.path;
- entry->sha1 = one.sha1;
- entry->mode = one.mode;
- entry->directory = S_ISDIR(one.mode) != 0;
- entry->executable = (one.mode & S_IXUSR) != 0;
- entry->symlink = S_ISLNK(one.mode) != 0;
- entry->next = NULL;
-
- *list_p = entry;
- list_p = &entry->next;
- }
- return ret;
-}
-
-static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
-{
- int len1 = strlen(name1);
- int len2 = strlen(name2);
- int len = len1 < len2 ? len1 : len2;
- int ret = memcmp(name1, name2, len);
- unsigned char c1, c2;
- if (ret)
- return ret;
- c1 = name1[len];
- c2 = name2[len];
- if (!c1 && dir1)
- c1 = '/';
- if (!c2 && dir2)
- c2 = '/';
- ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
- if (c1 && c2 && !ret)
- ret = len1 - len2;
- return ret;
-}
-
-static int unpack_trees_rec(struct tree_entry_list **posns, int len,
- const char *base, merge_fn_t fn, int *indpos)
-{
- int baselen = strlen(base);
- int src_size = len + 1;
- do {
- int i;
- const char *first;
- int firstdir = 0;
- int pathlen;
- unsigned ce_size;
- struct tree_entry_list **subposns;
- struct cache_entry **src;
- int any_files = 0;
- int any_dirs = 0;
- char *cache_name;
- int ce_stage;
-
- /* Find the first name in the input. */
-
- first = NULL;
- cache_name = NULL;
-
- /* Check the cache */
- if (merge && *indpos < active_nr) {
- /* This is a bit tricky: */
- /* If the index has a subdirectory (with
- * contents) as the first name, it'll get a
- * filename like "foo/bar". But that's after
- * "foo", so the entry in trees will get
- * handled first, at which point we'll go into
- * "foo", and deal with "bar" from the index,
- * because the base will be "foo/". The only
- * way we can actually have "foo/bar" first of
- * all the things is if the trees don't
- * contain "foo" at all, in which case we'll
- * handle "foo/bar" without going into the
- * directory, but that's fine (and will return
- * an error anyway, with the added unknown
- * file case.
- */
-
- cache_name = active_cache[*indpos]->name;
- if (strlen(cache_name) > baselen &&
- !memcmp(cache_name, base, baselen)) {
- cache_name += baselen;
- first = cache_name;
- } else {
- cache_name = NULL;
- }
- }
-
-#if DBRT_DEBUG > 1
- if (first)
- printf("index %s\n", first);
-#endif
- for (i = 0; i < len; i++) {
- if (!posns[i] || posns[i] == &df_conflict_list)
- continue;
-#if DBRT_DEBUG > 1
- printf("%d %s\n", i + 1, posns[i]->name);
-#endif
- if (!first || entcmp(first, firstdir,
- posns[i]->name,
- posns[i]->directory) > 0) {
- first = posns[i]->name;
- firstdir = posns[i]->directory;
- }
- }
- /* No name means we're done */
- if (!first)
- return 0;
-
- pathlen = strlen(first);
- ce_size = cache_entry_size(baselen + pathlen);
-
- src = xcalloc(src_size, sizeof(struct cache_entry *));
-
- subposns = xcalloc(len, sizeof(struct tree_list_entry *));
-
- if (cache_name && !strcmp(cache_name, first)) {
- any_files = 1;
- src[0] = active_cache[*indpos];
- remove_cache_entry_at(*indpos);
- }
-
- for (i = 0; i < len; i++) {
- struct cache_entry *ce;
-
- if (!posns[i] ||
- (posns[i] != &df_conflict_list &&
- strcmp(first, posns[i]->name))) {
- continue;
- }
-
- if (posns[i] == &df_conflict_list) {
- src[i + merge] = &df_conflict_entry;
- continue;
- }
-
- if (posns[i]->directory) {
- struct tree *tree = lookup_tree(posns[i]->sha1);
- any_dirs = 1;
- parse_tree(tree);
- subposns[i] = create_tree_entry_list(tree);
- posns[i] = posns[i]->next;
- src[i + merge] = &df_conflict_entry;
- continue;
- }
-
- if (!merge)
- ce_stage = 0;
- else if (i + 1 < head_idx)
- ce_stage = 1;
- else if (i + 1 > head_idx)
- ce_stage = 3;
- else
- ce_stage = 2;
-
- ce = xcalloc(1, ce_size);
- ce->ce_mode = create_ce_mode(posns[i]->mode);
- ce->ce_flags = create_ce_flags(baselen + pathlen,
- ce_stage);
- memcpy(ce->name, base, baselen);
- memcpy(ce->name + baselen, first, pathlen + 1);
-
- any_files = 1;
-
- memcpy(ce->sha1, posns[i]->sha1, 20);
- src[i + merge] = ce;
- subposns[i] = &df_conflict_list;
- posns[i] = posns[i]->next;
- }
- if (any_files) {
- if (merge) {
- int ret;
-
-#if DBRT_DEBUG > 1
- printf("%s:\n", first);
- for (i = 0; i < src_size; i++) {
- printf(" %d ", i);
- if (src[i])
- printf("%s\n", sha1_to_hex(src[i]->sha1));
- else
- printf("\n");
- }
-#endif
- ret = fn(src);
-
-#if DBRT_DEBUG > 1
- printf("Added %d entries\n", ret);
-#endif
- *indpos += ret;
- } else {
- for (i = 0; i < src_size; i++) {
- if (src[i]) {
- add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
- }
- }
- }
- }
- if (any_dirs) {
- char *newbase = xmalloc(baselen + 2 + pathlen);
- memcpy(newbase, base, baselen);
- memcpy(newbase + baselen, first, pathlen);
- newbase[baselen + pathlen] = '/';
- newbase[baselen + pathlen + 1] = '\0';
- if (unpack_trees_rec(subposns, len, newbase, fn,
- indpos))
- return -1;
- free(newbase);
- }
- free(subposns);
- free(src);
- } while (1);
-}
-
-static void reject_merge(struct cache_entry *ce)
-{
- die("Entry '%s' would be overwritten by merge. Cannot merge.",
- ce->name);
-}
-
-/* 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(char *name)
-{
- char *cp, *prev;
-
- 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 void progress_interval(int signum)
-{
- progress_update = 1;
-}
-
-static void setup_progress_signal(void)
-{
- struct sigaction sa;
- struct itimerval v;
-
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = progress_interval;
- sigemptyset(&sa.sa_mask);
- sa.sa_flags = SA_RESTART;
- sigaction(SIGALRM, &sa, NULL);
-
- v.it_interval.tv_sec = 1;
- v.it_interval.tv_usec = 0;
- v.it_value = v.it_interval;
- setitimer(ITIMER_REAL, &v, NULL);
-}
-
-static struct checkout state;
-static void check_updates(struct cache_entry **src, int nr)
-{
- unsigned short mask = htons(CE_UPDATE);
- unsigned last_percent = 200, cnt = 0, total = 0;
-
- if (update && verbose_update) {
- for (total = cnt = 0; cnt < nr; cnt++) {
- struct cache_entry *ce = src[cnt];
- if (!ce->ce_mode || ce->ce_flags & mask)
- total++;
- }
-
- /* Don't bother doing this for very small updates */
- if (total < 250)
- total = 0;
-
- if (total) {
- fprintf(stderr, "Checking files out...\n");
- setup_progress_signal();
- progress_update = 1;
- }
- cnt = 0;
- }
-
- while (nr--) {
- struct cache_entry *ce = *src++;
-
- if (total) {
- if (!ce->ce_mode || ce->ce_flags & mask) {
- unsigned percent;
- cnt++;
- percent = (cnt * 100) / total;
- if (percent != last_percent ||
- progress_update) {
- fprintf(stderr, "%4u%% (%u/%u) done\r",
- percent, cnt, total);
- last_percent = percent;
- progress_update = 0;
- }
- }
- }
- if (!ce->ce_mode) {
- if (update)
- unlink_entry(ce->name);
- continue;
- }
- if (ce->ce_flags & mask) {
- ce->ce_flags &= ~mask;
- if (update)
- checkout_entry(ce, &state, NULL);
- }
- }
- if (total) {
- signal(SIGALRM, SIG_IGN);
- fputc('\n', stderr);
- }
-}
-
-static int unpack_trees(merge_fn_t fn)
-{
- int indpos = 0;
- unsigned len = object_list_length(trees);
- struct tree_entry_list **posns;
- int i;
- struct object_list *posn = trees;
- merge_size = len;
-
- if (len) {
- posns = xmalloc(len * sizeof(struct tree_entry_list *));
- for (i = 0; i < len; i++) {
- posns[i] = create_tree_entry_list((struct tree *) posn->item);
- posn = posn->next;
- }
- if (unpack_trees_rec(posns, len, prefix ? prefix : "",
- fn, &indpos))
- return -1;
- }
-
- if (trivial_merges_only && nontrivial_merge)
- die("Merge requires file-level merging");
-
- check_updates(active_cache, active_nr);
- return 0;
-}
-
static int list_tree(unsigned char *sha1)
{
struct tree *tree = parse_tree_indirect(sha1);
@@ -425,386 +23,6 @@ static int list_tree(unsigned char *sha1)
return 0;
}
-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 &&
- !memcmp(a->sha1, b->sha1, 20);
-}
-
-
-/*
- * When a CE gets turned into an unmerged entry, we
- * want it to be up-to-date
- */
-static void verify_uptodate(struct cache_entry *ce)
-{
- struct stat st;
-
- if (index_only || reset)
- return;
-
- if (!lstat(ce->name, &st)) {
- unsigned changed = ce_match_stat(ce, &st, 1);
- if (!changed)
- return;
- errno = 0;
- }
- if (reset) {
- ce->ce_flags |= htons(CE_UPDATE);
- return;
- }
- if (errno == ENOENT)
- return;
- die("Entry '%s' not uptodate. Cannot merge.", ce->name);
-}
-
-static void invalidate_ce_path(struct cache_entry *ce)
-{
- if (ce)
- cache_tree_invalidate_path(active_cache_tree, ce->name);
-}
-
-/*
- * We do not want to remove or overwrite a working tree file that
- * is not tracked.
- */
-static void verify_absent(const char *path, const char *action)
-{
- struct stat st;
-
- if (index_only || reset || !update)
- return;
- if (!lstat(path, &st))
- die("Untracked working tree file '%s' "
- "would be %s by merge.", path, action);
-}
-
-static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
-{
- merge->ce_flags |= htons(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.
- */
- if (same(old, merge)) {
- *merge = *old;
- } else {
- verify_uptodate(old);
- invalidate_ce_path(old);
- }
- }
- else {
- verify_absent(merge->name, "overwritten");
- invalidate_ce_path(merge);
- }
-
- merge->ce_flags &= ~htons(CE_STAGEMASK);
- add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
- return 1;
-}
-
-static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
-{
- if (old)
- verify_uptodate(old);
- else
- verify_absent(ce->name, "removed");
- ce->ce_mode = 0;
- add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
- invalidate_ce_path(ce);
- return 1;
-}
-
-static int keep_entry(struct cache_entry *ce)
-{
- add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
- 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,
- ntohl(ce->ce_mode),
- sha1_to_hex(ce->sha1),
- ce_stage(ce),
- ce->name);
-}
-#endif
-
-static int threeway_merge(struct cache_entry **stages)
-{
- struct cache_entry *index;
- struct cache_entry *head;
- struct cache_entry *remote = stages[head_idx + 1];
- int count;
- int head_match = 0;
- int remote_match = 0;
- const char *path = NULL;
-
- 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 < head_idx; i++) {
- if (!stages[i])
- any_anc_missing = 1;
- else {
- if (!path)
- path = stages[i]->name;
- no_anc_exists = 0;
- }
- }
-
- index = stages[0];
- head = stages[head_idx];
-
- if (head == &df_conflict_entry) {
- df_conflict_head = 1;
- head = NULL;
- }
-
- if (remote == &df_conflict_entry) {
- df_conflict_remote = 1;
- remote = NULL;
- }
-
- if (!path && index)
- path = index->name;
- if (!path && head)
- path = head->name;
- if (!path && remote)
- path = remote->name;
-
- /* First, if there's a #16 situation, note that to prevent #13
- * and #14.
- */
- if (!same(remote, head)) {
- for (i = 1; i < 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))
- reject_merge(index);
- return merged_entry(remote, index);
- }
- /*
- * If we have an entry in the index cache, then we want to
- * make sure that it matches head.
- */
- if (index && !same(index, head)) {
- reject_merge(index);
- }
-
- if (head) {
- /* #5ALT, #15 */
- if (same(head, remote))
- return merged_entry(head, index);
- /* #13, #3ALT */
- if (!df_conflict_remote && remote_match && !head_match)
- return merged_entry(head, index);
- }
-
- /* #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 (aggressive) {
- int head_deleted = !head && !df_conflict_head;
- int remote_deleted = !remote && !df_conflict_remote;
- /*
- * 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);
- else if (path)
- verify_absent(path, "removed");
- return 0;
- }
- /*
- * Added in both, identically.
- */
- if (no_anc_exists && head && remote && same(head, remote))
- return merged_entry(head, index);
-
- }
-
- /* 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) {
- verify_uptodate(index);
- }
- else if (path)
- verify_absent(path, "overwritten");
-
- nontrivial_merge = 1;
-
- /* #2, #3, #4, #6, #7, #9, #11. */
- count = 0;
- if (!head_match || !remote_match) {
- for (i = 1; i < head_idx; i++) {
- if (stages[i]) {
- keep_entry(stages[i]);
- 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); }
- if (remote) { count += keep_entry(remote); }
- 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>.
- *
- */
-static int twoway_merge(struct cache_entry **src)
-{
- struct cache_entry *current = src[0];
- struct cache_entry *oldtree = src[1], *newtree = src[2];
-
- if (merge_size != 2)
- return error("Cannot do a twoway merge of %d trees",
- merge_size);
-
- 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);
- }
- else if (oldtree && !newtree && same(current, oldtree)) {
- /* 10 or 11 */
- return deleted_entry(oldtree, current);
- }
- else if (oldtree && newtree &&
- same(current, oldtree) && !same(current, newtree)) {
- /* 20 or 21 */
- return merged_entry(newtree, current);
- }
- else {
- /* all other failures */
- if (oldtree)
- reject_merge(oldtree);
- if (current)
- reject_merge(current);
- if (newtree)
- reject_merge(newtree);
- return -1;
- }
- }
- else if (newtree)
- return merged_entry(newtree, current);
- else
- return deleted_entry(oldtree, current);
-}
-
-/*
- * Bind merge.
- *
- * Keep the index entries at stage0, collapse stage1 but make sure
- * stage0 does not have anything there.
- */
-static int bind_merge(struct cache_entry **src)
-{
- struct cache_entry *old = src[0];
- struct cache_entry *a = src[1];
-
- if (merge_size != 1)
- return error("Cannot do a bind merge of %d trees\n",
- merge_size);
- if (a && old)
- die("Entry '%s' overlaps. Cannot bind.", a->name);
- if (!a)
- return keep_entry(old);
- else
- return merged_entry(a, NULL);
-}
-
-/*
- * One-way merge.
- *
- * The rule is:
- * - take the stat information from stage0, take the data from stage1
- */
-static int oneway_merge(struct cache_entry **src)
-{
- struct cache_entry *old = src[0];
- struct cache_entry *a = src[1];
-
- if (merge_size != 1)
- return error("Cannot do a oneway merge of %d trees",
- merge_size);
-
- if (!a)
- return deleted_entry(old, old);
- if (old && same(old, a)) {
- if (reset) {
- struct stat st;
- if (lstat(old->name, &st) ||
- ce_match_stat(old, &st, 1))
- old->ce_flags |= htons(CE_UPDATE);
- }
- return keep_entry(old);
- }
- return merged_entry(a, old);
-}
-
static int read_cache_unmerged(void)
{
int i;
@@ -818,7 +36,7 @@ static int read_cache_unmerged(void)
if (ce_stage(ce)) {
if (last && !strcmp(ce->name, last->name))
continue;
- invalidate_ce_path(ce);
+ cache_tree_invalidate_path(active_cache_tree, ce->name);
last = ce;
ce->ce_mode = 0;
ce->ce_flags &= ~htons(CE_STAGEMASK);
@@ -874,22 +92,18 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
{
int i, newfd, stage = 0;
unsigned char sha1[20];
- merge_fn_t fn = NULL;
+ struct unpack_trees_options opts;
- df_conflict_list.next = &df_conflict_list;
- state.base_dir = "";
- state.force = 1;
- state.quiet = 1;
- state.refresh_cache = 1;
+ memset(&opts, 0, sizeof(opts));
+ opts.head_idx = -1;
+ setup_git_directory();
git_config(git_default_config);
newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);
git_config(git_default_config);
- merge = 0;
- reset = 0;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
@@ -897,12 +111,12 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
* the working tree.
*/
if (!strcmp(arg, "-u")) {
- update = 1;
+ opts.update = 1;
continue;
}
if (!strcmp(arg, "-v")) {
- verbose_update = 1;
+ opts.verbose_update = 1;
continue;
}
@@ -910,7 +124,7 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
* not even look at the working tree.
*/
if (!strcmp(arg, "-i")) {
- index_only = 1;
+ opts.index_only = 1;
continue;
}
@@ -919,10 +133,10 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
* given subdirectory.
*/
if (!strncmp(arg, "--prefix=", 9)) {
- if (stage || merge || prefix)
+ if (stage || opts.merge || opts.prefix)
usage(read_tree_usage);
- prefix = arg + 9;
- merge = 1;
+ opts.prefix = arg + 9;
+ opts.merge = 1;
stage = 1;
if (read_cache_unmerged())
die("you need to resolve your current index first");
@@ -934,38 +148,38 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
* correspond to them.
*/
if (!strcmp(arg, "--reset")) {
- if (stage || merge || prefix)
+ if (stage || opts.merge || opts.prefix)
usage(read_tree_usage);
- reset = 1;
- merge = 1;
+ opts.reset = 1;
+ opts.merge = 1;
stage = 1;
read_cache_unmerged();
continue;
}
if (!strcmp(arg, "--trivial")) {
- trivial_merges_only = 1;
+ opts.trivial_merges_only = 1;
continue;
}
if (!strcmp(arg, "--aggressive")) {
- aggressive = 1;
+ opts.aggressive = 1;
continue;
}
/* "-m" stands for "merge", meaning we start in stage 1 */
if (!strcmp(arg, "-m")) {
- if (stage || merge || prefix)
+ 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;
- merge = 1;
+ opts.merge = 1;
continue;
}
/* using -u and -i at the same time makes no sense */
- if (1 < index_only + update)
+ if (1 < opts.index_only + opts.update)
usage(read_tree_usage);
if (get_sha1(arg, sha1))
@@ -974,52 +188,53 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
die("failed to unpack tree object %s", arg);
stage++;
}
- if ((update||index_only) && !merge)
+ if ((opts.update||opts.index_only) && !opts.merge)
usage(read_tree_usage);
- if (prefix) {
- int pfxlen = strlen(prefix);
+ if (opts.prefix) {
+ int pfxlen = strlen(opts.prefix);
int pos;
- if (prefix[pfxlen-1] != '/')
+ if (opts.prefix[pfxlen-1] != '/')
die("prefix must end with /");
if (stage != 2)
die("binding merge takes only one tree");
- pos = cache_name_pos(prefix, pfxlen);
+ 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, prefix, pfxlen))
- die("subdirectory '%s' already exists.", prefix);
- pos = cache_name_pos(prefix, pfxlen-1);
+ !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, prefix);
+ die("file '%.*s' already exists.",
+ pfxlen-1, opts.prefix);
}
- if (merge) {
+ if (opts.merge) {
if (stage < 2)
die("just how do you expect me to merge %d trees?", stage-1);
switch (stage - 1) {
case 1:
- fn = prefix ? bind_merge : oneway_merge;
+ opts.fn = opts.prefix ? bind_merge : oneway_merge;
break;
case 2:
- fn = twoway_merge;
+ opts.fn = twoway_merge;
break;
case 3:
default:
- fn = threeway_merge;
+ opts.fn = threeway_merge;
cache_tree_free(&active_cache_tree);
break;
}
if (stage - 1 >= 3)
- head_idx = stage - 2;
+ opts.head_idx = stage - 2;
else
- head_idx = 1;
+ opts.head_idx = 1;
}
- unpack_trees(fn);
+ unpack_trees(trees, &opts);
/*
* When reading only one tree (either the most basic form,
@@ -1027,7 +242,7 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
* valid cache-tree because the index must match exactly
* what came from the tree.
*/
- if (trees && trees->item && !prefix && (!merge || (stage == 2))) {
+ if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
cache_tree_free(&active_cache_tree);
prime_cache_tree();
}
diff --git a/unpack-trees.c b/unpack-trees.c
new file mode 100644
index 0000000000..a20639be70
--- /dev/null
+++ b/unpack-trees.c
@@ -0,0 +1,799 @@
+#include <signal.h>
+#include <sys/time.h>
+#include "cache.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "cache-tree.h"
+#include "unpack-trees.h"
+
+#define DBRT_DEBUG 1
+
+struct tree_entry_list {
+ struct tree_entry_list *next;
+ unsigned directory : 1;
+ unsigned executable : 1;
+ unsigned symlink : 1;
+ unsigned int mode;
+ const char *name;
+ const unsigned char *sha1;
+};
+
+static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
+{
+ struct tree_desc desc;
+ struct name_entry one;
+ struct tree_entry_list *ret = NULL;
+ struct tree_entry_list **list_p = &ret;
+
+ if (!tree->object.parsed)
+ parse_tree(tree);
+
+ desc.buf = tree->buffer;
+ desc.size = tree->size;
+
+ while (tree_entry(&desc, &one)) {
+ struct tree_entry_list *entry;
+
+ entry = xmalloc(sizeof(struct tree_entry_list));
+ entry->name = one.path;
+ entry->sha1 = one.sha1;
+ entry->mode = one.mode;
+ entry->directory = S_ISDIR(one.mode) != 0;
+ entry->executable = (one.mode & S_IXUSR) != 0;
+ entry->symlink = S_ISLNK(one.mode) != 0;
+ entry->next = NULL;
+
+ *list_p = entry;
+ list_p = &entry->next;
+ }
+ return ret;
+}
+
+static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
+{
+ int len1 = strlen(name1);
+ int len2 = strlen(name2);
+ int len = len1 < len2 ? len1 : len2;
+ int ret = memcmp(name1, name2, len);
+ unsigned char c1, c2;
+ if (ret)
+ return ret;
+ c1 = name1[len];
+ c2 = name2[len];
+ if (!c1 && dir1)
+ c1 = '/';
+ if (!c2 && dir2)
+ c2 = '/';
+ ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
+ if (c1 && c2 && !ret)
+ ret = len1 - len2;
+ return ret;
+}
+
+static int unpack_trees_rec(struct tree_entry_list **posns, int len,
+ const char *base, struct unpack_trees_options *o,
+ int *indpos,
+ struct tree_entry_list *df_conflict_list)
+{
+ int baselen = strlen(base);
+ int src_size = len + 1;
+ do {
+ int i;
+ const char *first;
+ int firstdir = 0;
+ int pathlen;
+ unsigned ce_size;
+ struct tree_entry_list **subposns;
+ struct cache_entry **src;
+ int any_files = 0;
+ int any_dirs = 0;
+ char *cache_name;
+ int ce_stage;
+
+ /* Find the first name in the input. */
+
+ first = NULL;
+ cache_name = NULL;
+
+ /* Check the cache */
+ if (o->merge && *indpos < active_nr) {
+ /* This is a bit tricky: */
+ /* If the index has a subdirectory (with
+ * contents) as the first name, it'll get a
+ * filename like "foo/bar". But that's after
+ * "foo", so the entry in trees will get
+ * handled first, at which point we'll go into
+ * "foo", and deal with "bar" from the index,
+ * because the base will be "foo/". The only
+ * way we can actually have "foo/bar" first of
+ * all the things is if the trees don't
+ * contain "foo" at all, in which case we'll
+ * handle "foo/bar" without going into the
+ * directory, but that's fine (and will return
+ * an error anyway, with the added unknown
+ * file case.
+ */
+
+ cache_name = active_cache[*indpos]->name;
+ if (strlen(cache_name) > baselen &&
+ !memcmp(cache_name, base, baselen)) {
+ cache_name += baselen;
+ first = cache_name;
+ } else {
+ cache_name = NULL;
+ }
+ }
+
+#if DBRT_DEBUG > 1
+ if (first)
+ printf("index %s\n", first);
+#endif
+ for (i = 0; i < len; i++) {
+ if (!posns[i] || posns[i] == df_conflict_list)
+ continue;
+#if DBRT_DEBUG > 1
+ printf("%d %s\n", i + 1, posns[i]->name);
+#endif
+ if (!first || entcmp(first, firstdir,
+ posns[i]->name,
+ posns[i]->directory) > 0) {
+ first = posns[i]->name;
+ firstdir = posns[i]->directory;
+ }
+ }
+ /* No name means we're done */
+ if (!first)
+ return 0;
+
+ pathlen = strlen(first);
+ ce_size = cache_entry_size(baselen + pathlen);
+
+ src = xcalloc(src_size, sizeof(struct cache_entry *));
+
+ subposns = xcalloc(len, sizeof(struct tree_list_entry *));
+
+ if (cache_name && !strcmp(cache_name, first)) {
+ any_files = 1;
+ src[0] = active_cache[*indpos];
+ remove_cache_entry_at(*indpos);
+ }
+
+ for (i = 0; i < len; i++) {
+ struct cache_entry *ce;
+
+ if (!posns[i] ||
+ (posns[i] != df_conflict_list &&
+ strcmp(first, posns[i]->name))) {
+ continue;
+ }
+
+ if (posns[i] == df_conflict_list) {
+ src[i + o->merge] = o->df_conflict_entry;
+ continue;
+ }
+
+ if (posns[i]->directory) {
+ struct tree *tree = lookup_tree(posns[i]->sha1);
+ any_dirs = 1;
+ parse_tree(tree);
+ subposns[i] = create_tree_entry_list(tree);
+ posns[i] = posns[i]->next;
+ src[i + o->merge] = o->df_conflict_entry;
+ continue;
+ }
+
+ if (!o->merge)
+ ce_stage = 0;
+ else if (i + 1 < o->head_idx)
+ ce_stage = 1;
+ else if (i + 1 > o->head_idx)
+ ce_stage = 3;
+ else
+ ce_stage = 2;
+
+ ce = xcalloc(1, ce_size);
+ ce->ce_mode = create_ce_mode(posns[i]->mode);
+ ce->ce_flags = create_ce_flags(baselen + pathlen,
+ ce_stage);
+ memcpy(ce->name, base, baselen);
+ memcpy(ce->name + baselen, first, pathlen + 1);
+
+ any_files = 1;
+
+ memcpy(ce->sha1, posns[i]->sha1, 20);
+ src[i + o->merge] = ce;
+ subposns[i] = df_conflict_list;
+ posns[i] = posns[i]->next;
+ }
+ if (any_files) {
+ if (o->merge) {
+ int ret;
+
+#if DBRT_DEBUG > 1
+ printf("%s:\n", first);
+ for (i = 0; i < src_size; i++) {
+ printf(" %d ", i);
+ if (src[i])
+ printf("%s\n", sha1_to_hex(src[i]->sha1));
+ else
+ printf("\n");
+ }
+#endif
+ ret = o->fn(src, o);
+
+#if DBRT_DEBUG > 1
+ printf("Added %d entries\n", ret);
+#endif
+ *indpos += ret;
+ } else {
+ for (i = 0; i < src_size; i++) {
+ if (src[i]) {
+ add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
+ }
+ }
+ }
+ }
+ if (any_dirs) {
+ char *newbase = xmalloc(baselen + 2 + pathlen);
+ memcpy(newbase, base, baselen);
+ memcpy(newbase + baselen, first, pathlen);
+ newbase[baselen + pathlen] = '/';
+ newbase[baselen + pathlen + 1] = '\0';
+ if (unpack_trees_rec(subposns, len, newbase, o,
+ indpos, df_conflict_list))
+ return -1;
+ free(newbase);
+ }
+ free(subposns);
+ free(src);
+ } while (1);
+}
+
+/* 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(char *name)
+{
+ char *cp, *prev;
+
+ 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 volatile int progress_update = 0;
+
+static void progress_interval(int signum)
+{
+ progress_update = 1;
+}
+
+static void setup_progress_signal(void)
+{
+ struct sigaction sa;
+ struct itimerval v;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = progress_interval;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART;
+ sigaction(SIGALRM, &sa, NULL);
+
+ v.it_interval.tv_sec = 1;
+ v.it_interval.tv_usec = 0;
+ v.it_value = v.it_interval;
+ setitimer(ITIMER_REAL, &v, NULL);
+}
+
+static struct checkout state;
+static void check_updates(struct cache_entry **src, int nr,
+ struct unpack_trees_options *o)
+{
+ unsigned short mask = htons(CE_UPDATE);
+ unsigned last_percent = 200, cnt = 0, total = 0;
+
+ if (o->update && o->verbose_update) {
+ for (total = cnt = 0; cnt < nr; cnt++) {
+ struct cache_entry *ce = src[cnt];
+ if (!ce->ce_mode || ce->ce_flags & mask)
+ total++;
+ }
+
+ /* Don't bother doing this for very small updates */
+ if (total < 250)
+ total = 0;
+
+ if (total) {
+ fprintf(stderr, "Checking files out...\n");
+ setup_progress_signal();
+ progress_update = 1;
+ }
+ cnt = 0;
+ }
+
+ while (nr--) {
+ struct cache_entry *ce = *src++;
+
+ if (total) {
+ if (!ce->ce_mode || ce->ce_flags & mask) {
+ unsigned percent;
+ cnt++;
+ percent = (cnt * 100) / total;
+ if (percent != last_percent ||
+ progress_update) {
+ fprintf(stderr, "%4u%% (%u/%u) done\r",
+ percent, cnt, total);
+ last_percent = percent;
+ progress_update = 0;
+ }
+ }
+ }
+ if (!ce->ce_mode) {
+ if (o->update)
+ unlink_entry(ce->name);
+ continue;
+ }
+ if (ce->ce_flags & mask) {
+ ce->ce_flags &= ~mask;
+ if (o->update)
+ checkout_entry(ce, &state, NULL);
+ }
+ }
+ if (total) {
+ signal(SIGALRM, SIG_IGN);
+ fputc('\n', stderr);
+ }
+}
+
+int unpack_trees(struct object_list *trees, struct unpack_trees_options *o)
+{
+ int indpos = 0;
+ unsigned len = object_list_length(trees);
+ struct tree_entry_list **posns;
+ int i;
+ struct object_list *posn = trees;
+ struct tree_entry_list df_conflict_list;
+ struct cache_entry df_conflict_entry;
+
+ memset(&df_conflict_list, 0, sizeof(df_conflict_list));
+ df_conflict_list.next = &df_conflict_list;
+ memset(&state, 0, sizeof(state));
+ state.base_dir = "";
+ state.force = 1;
+ state.quiet = 1;
+ state.refresh_cache = 1;
+
+ o->merge_size = len;
+ memset(&df_conflict_entry, 0, sizeof(df_conflict_entry));
+ o->df_conflict_entry = &df_conflict_entry;
+
+ if (len) {
+ posns = xmalloc(len * sizeof(struct tree_entry_list *));
+ for (i = 0; i < len; i++) {
+ posns[i] = create_tree_entry_list((struct tree *) posn->item);
+ posn = posn->next;
+ }
+ if (unpack_trees_rec(posns, len, o->prefix ? o->prefix : "",
+ o, &indpos, &df_conflict_list))
+ return -1;
+ }
+
+ if (o->trivial_merges_only && o->nontrivial_merge)
+ die("Merge requires file-level merging");
+
+ check_updates(active_cache, active_nr, o);
+ return 0;
+}
+
+/* Here come the merge functions */
+
+static void reject_merge(struct cache_entry *ce)
+{
+ die("Entry '%s' would be overwritten by merge. Cannot merge.",
+ 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 &&
+ !memcmp(a->sha1, b->sha1, 20);
+}
+
+
+/*
+ * When a CE gets turned into an unmerged entry, we
+ * want it to be up-to-date
+ */
+static void verify_uptodate(struct cache_entry *ce,
+ struct unpack_trees_options *o)
+{
+ struct stat st;
+
+ if (o->index_only || o->reset)
+ return;
+
+ if (!lstat(ce->name, &st)) {
+ unsigned changed = ce_match_stat(ce, &st, 1);
+ if (!changed)
+ return;
+ errno = 0;
+ }
+ if (o->reset) {
+ ce->ce_flags |= htons(CE_UPDATE);
+ return;
+ }
+ if (errno == ENOENT)
+ return;
+ die("Entry '%s' not uptodate. Cannot merge.", ce->name);
+}
+
+static void invalidate_ce_path(struct cache_entry *ce)
+{
+ if (ce)
+ cache_tree_invalidate_path(active_cache_tree, ce->name);
+}
+
+/*
+ * We do not want to remove or overwrite a working tree file that
+ * is not tracked.
+ */
+static void verify_absent(const char *path, const char *action,
+ struct unpack_trees_options *o)
+{
+ struct stat st;
+
+ if (o->index_only || o->reset || !o->update)
+ return;
+ if (!lstat(path, &st))
+ die("Untracked working tree file '%s' "
+ "would be %s by merge.", path, action);
+}
+
+static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
+ struct unpack_trees_options *o)
+{
+ merge->ce_flags |= htons(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.
+ */
+ if (same(old, merge)) {
+ *merge = *old;
+ } else {
+ verify_uptodate(old, o);
+ invalidate_ce_path(old);
+ }
+ }
+ else {
+ verify_absent(merge->name, "overwritten", o);
+ invalidate_ce_path(merge);
+ }
+
+ merge->ce_flags &= ~htons(CE_STAGEMASK);
+ add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
+ return 1;
+}
+
+static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
+ struct unpack_trees_options *o)
+{
+ if (old)
+ verify_uptodate(old, o);
+ else
+ verify_absent(ce->name, "removed", o);
+ ce->ce_mode = 0;
+ add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
+ invalidate_ce_path(ce);
+ return 1;
+}
+
+static int keep_entry(struct cache_entry *ce)
+{
+ add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
+ 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,
+ ntohl(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;
+ const char *path = NULL;
+
+ 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])
+ any_anc_missing = 1;
+ else {
+ if (!path)
+ path = stages[i]->name;
+ 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;
+ }
+
+ if (!path && index)
+ path = index->name;
+ if (!path && head)
+ path = head->name;
+ if (!path && remote)
+ path = remote->name;
+
+ /* 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))
+ reject_merge(index);
+ 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)) {
+ reject_merge(index);
+ }
+
+ 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;
+ /*
+ * 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);
+ else if (path)
+ verify_absent(path, "removed", o);
+ 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) {
+ verify_uptodate(index, o);
+ }
+ else if (path)
+ verify_absent(path, "overwritten", o);
+
+ o->nontrivial_merge = 1;
+
+ /* #2, #3, #4, #6, #7, #9, #11. */
+ count = 0;
+ if (!head_match || !remote_match) {
+ for (i = 1; i < o->head_idx; i++) {
+ if (stages[i]) {
+ keep_entry(stages[i]);
+ 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); }
+ if (remote) { count += keep_entry(remote); }
+ 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], *newtree = src[2];
+
+ if (o->merge_size != 2)
+ return error("Cannot do a twoway merge of %d trees",
+ o->merge_size);
+
+ 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);
+ }
+ 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)
+ reject_merge(oldtree);
+ if (current)
+ reject_merge(current);
+ if (newtree)
+ reject_merge(newtree);
+ return -1;
+ }
+ }
+ else if (newtree)
+ return merged_entry(newtree, current, o);
+ else
+ 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)
+ die("Entry '%s' overlaps. Cannot bind.", a->name);
+ if (!a)
+ return keep_entry(old);
+ 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)) {
+ if (o->reset) {
+ struct stat st;
+ if (lstat(old->name, &st) ||
+ ce_match_stat(old, &st, 1))
+ old->ce_flags |= htons(CE_UPDATE);
+ }
+ return keep_entry(old);
+ }
+ return merged_entry(a, old, o);
+}
diff --git a/unpack-trees.h b/unpack-trees.h
new file mode 100644
index 0000000000..c4601621cd
--- /dev/null
+++ b/unpack-trees.h
@@ -0,0 +1,35 @@
+#ifndef UNPACK_TREES_H
+#define UNPACK_TREES_H
+
+struct unpack_trees_options;
+
+typedef int (*merge_fn_t)(struct cache_entry **src,
+ struct unpack_trees_options *options);
+
+struct unpack_trees_options {
+ int reset;
+ int merge;
+ int update;
+ int index_only;
+ int nontrivial_merge;
+ int trivial_merges_only;
+ int verbose_update;
+ int aggressive;
+ const char *prefix;
+ merge_fn_t fn;
+
+ int head_idx;
+ int merge_size;
+
+ struct cache_entry *df_conflict_entry;
+};
+
+extern int unpack_trees(struct object_list *trees,
+ struct unpack_trees_options *options);
+
+int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o);
+int twoway_merge(struct cache_entry **src, struct unpack_trees_options *o);
+int bind_merge(struct cache_entry **src, struct unpack_trees_options *o);
+int oneway_merge(struct cache_entry **src, struct unpack_trees_options *o);
+
+#endif