git/unpack-trees.c
Junio C Hamano c4758d3c93 Fix read-tree not to discard errors
This fixes the issue identified with recently added tests to t1004

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-18 22:17:22 -07:00

942 lines
22 KiB
C

#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"
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(char *name, char *last_symlink)
{
char *cp, *prev;
if (has_symlink_leading_path(name, last_symlink))
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;
char last_symlink[PATH_MAX];
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;
}
*last_symlink = '\0';
for (i = 0; i < index->cache_nr; i++) {
struct cache_entry *ce = index->cache[i];
if (ce->ce_flags & (CE_UPDATE | CE_REMOVE))
display_progress(progress, ++cnt);
if (ce->ce_flags & CE_REMOVE) {
if (o->update)
unlink_entry(ce->name, last_symlink);
remove_index_entry_at(&o->result, i);
i--;
continue;
}
if (ce->ce_flags & CE_UPDATE) {
ce->ce_flags &= ~CE_UPDATE;
if (o->update) {
errs |= checkout_entry(ce, &state, NULL);
*last_symlink = '\0';
}
}
}
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;
}
int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options *o)
{
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;
if (check_updates(o))
return -1;
if (o->dst_index)
*o->dst_index = o->result;
return 0;
}
/* Here come the merge functions */
static int reject_merge(struct cache_entry *ce)
{
return error("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 &&
!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("Entry '%s' not uptodate. Cannot merge.", 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("Updating '%s' would lose untracked files in it",
ce->name);
free(pathbuf);
return cnt;
}
/*
* 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->name, NULL))
return 0;
if (!lstat(ce->name, &st)) {
int cnt;
int dtype = ce_to_dtype(ce);
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.
*/
cnt = index_name_pos(&o->result, ce->name, strlen(ce->name));
if (0 <= cnt) {
struct cache_entry *ce = o->result.cache[cnt];
if (ce->ce_flags & CE_REMOVE)
return 0;
}
return o->gently ? -1 :
error("Untracked working tree file '%s' "
"would be %s by merge.", 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);
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);
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);
if (current)
return o->gently ? -1 : reject_merge(current);
if (newtree)
return o->gently ? -1 : reject_merge(newtree);
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("Entry '%s' overlaps with '%s'. Cannot bind.", 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);
}