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-rw-r--r--read-cache.c1676
1 files changed, 1676 insertions, 0 deletions
diff --git a/read-cache.c b/read-cache.c
new file mode 100644
index 0000000000..309b77a6c9
--- /dev/null
+++ b/read-cache.c
@@ -0,0 +1,1676 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#define NO_THE_INDEX_COMPATIBILITY_MACROS
+#include "cache.h"
+#include "cache-tree.h"
+#include "refs.h"
+#include "dir.h"
+#include "tree.h"
+#include "commit.h"
+#include "blob.h"
+#include "resolve-undo.h"
+
+static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
+
+/* Index extensions.
+ *
+ * The first letter should be 'A'..'Z' for extensions that are not
+ * necessary for a correct operation (i.e. optimization data).
+ * When new extensions are added that _needs_ to be understood in
+ * order to correctly interpret the index file, pick character that
+ * is outside the range, to cause the reader to abort.
+ */
+
+#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
+#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
+#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUN" */
+
+struct index_state the_index;
+
+static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
+{
+ istate->cache[nr] = ce;
+ add_name_hash(istate, ce);
+}
+
+static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
+{
+ struct cache_entry *old = istate->cache[nr];
+
+ remove_name_hash(old);
+ set_index_entry(istate, nr, ce);
+ istate->cache_changed = 1;
+}
+
+void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
+{
+ struct cache_entry *old = istate->cache[nr], *new;
+ int namelen = strlen(new_name);
+
+ new = xmalloc(cache_entry_size(namelen));
+ copy_cache_entry(new, old);
+ new->ce_flags &= ~(CE_STATE_MASK | CE_NAMEMASK);
+ new->ce_flags |= (namelen >= CE_NAMEMASK ? CE_NAMEMASK : namelen);
+ memcpy(new->name, new_name, namelen + 1);
+
+ cache_tree_invalidate_path(istate->cache_tree, old->name);
+ remove_index_entry_at(istate, nr);
+ add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
+}
+
+/*
+ * This only updates the "non-critical" parts of the directory
+ * cache, ie the parts that aren't tracked by GIT, and only used
+ * to validate the cache.
+ */
+void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
+{
+ ce->ce_ctime.sec = (unsigned int)st->st_ctime;
+ ce->ce_mtime.sec = (unsigned int)st->st_mtime;
+ ce->ce_ctime.nsec = ST_CTIME_NSEC(*st);
+ ce->ce_mtime.nsec = ST_MTIME_NSEC(*st);
+ ce->ce_dev = st->st_dev;
+ ce->ce_ino = st->st_ino;
+ ce->ce_uid = st->st_uid;
+ ce->ce_gid = st->st_gid;
+ ce->ce_size = st->st_size;
+
+ if (assume_unchanged)
+ ce->ce_flags |= CE_VALID;
+
+ if (S_ISREG(st->st_mode))
+ ce_mark_uptodate(ce);
+}
+
+static int ce_compare_data(struct cache_entry *ce, struct stat *st)
+{
+ int match = -1;
+ int fd = open(ce->name, O_RDONLY);
+
+ if (fd >= 0) {
+ unsigned char sha1[20];
+ if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
+ match = hashcmp(sha1, ce->sha1);
+ /* index_fd() closed the file descriptor already */
+ }
+ return match;
+}
+
+static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
+{
+ int match = -1;
+ void *buffer;
+ unsigned long size;
+ enum object_type type;
+ struct strbuf sb = STRBUF_INIT;
+
+ if (strbuf_readlink(&sb, ce->name, expected_size))
+ return -1;
+
+ buffer = read_sha1_file(ce->sha1, &type, &size);
+ if (buffer) {
+ if (size == sb.len)
+ match = memcmp(buffer, sb.buf, size);
+ free(buffer);
+ }
+ strbuf_release(&sb);
+ return match;
+}
+
+static int ce_compare_gitlink(struct cache_entry *ce)
+{
+ unsigned char sha1[20];
+
+ /*
+ * We don't actually require that the .git directory
+ * under GITLINK directory be a valid git directory. It
+ * might even be missing (in case nobody populated that
+ * sub-project).
+ *
+ * If so, we consider it always to match.
+ */
+ if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
+ return 0;
+ return hashcmp(sha1, ce->sha1);
+}
+
+static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
+{
+ switch (st->st_mode & S_IFMT) {
+ case S_IFREG:
+ if (ce_compare_data(ce, st))
+ return DATA_CHANGED;
+ break;
+ case S_IFLNK:
+ if (ce_compare_link(ce, xsize_t(st->st_size)))
+ return DATA_CHANGED;
+ break;
+ case S_IFDIR:
+ if (S_ISGITLINK(ce->ce_mode))
+ return ce_compare_gitlink(ce) ? DATA_CHANGED : 0;
+ default:
+ return TYPE_CHANGED;
+ }
+ return 0;
+}
+
+static int is_empty_blob_sha1(const unsigned char *sha1)
+{
+ static const unsigned char empty_blob_sha1[20] = {
+ 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b,
+ 0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91
+ };
+
+ return !hashcmp(sha1, empty_blob_sha1);
+}
+
+static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
+{
+ unsigned int changed = 0;
+
+ if (ce->ce_flags & CE_REMOVE)
+ return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
+
+ switch (ce->ce_mode & S_IFMT) {
+ case S_IFREG:
+ changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
+ /* We consider only the owner x bit to be relevant for
+ * "mode changes"
+ */
+ if (trust_executable_bit &&
+ (0100 & (ce->ce_mode ^ st->st_mode)))
+ changed |= MODE_CHANGED;
+ break;
+ case S_IFLNK:
+ if (!S_ISLNK(st->st_mode) &&
+ (has_symlinks || !S_ISREG(st->st_mode)))
+ changed |= TYPE_CHANGED;
+ break;
+ case S_IFGITLINK:
+ /* We ignore most of the st_xxx fields for gitlinks */
+ if (!S_ISDIR(st->st_mode))
+ changed |= TYPE_CHANGED;
+ else if (ce_compare_gitlink(ce))
+ changed |= DATA_CHANGED;
+ return changed;
+ default:
+ die("internal error: ce_mode is %o", ce->ce_mode);
+ }
+ if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
+ changed |= MTIME_CHANGED;
+ if (trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime)
+ changed |= CTIME_CHANGED;
+
+#ifdef USE_NSEC
+ if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
+ changed |= MTIME_CHANGED;
+ if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
+ changed |= CTIME_CHANGED;
+#endif
+
+ if (ce->ce_uid != (unsigned int) st->st_uid ||
+ ce->ce_gid != (unsigned int) st->st_gid)
+ changed |= OWNER_CHANGED;
+ if (ce->ce_ino != (unsigned int) st->st_ino)
+ changed |= INODE_CHANGED;
+
+#ifdef USE_STDEV
+ /*
+ * st_dev breaks on network filesystems where different
+ * clients will have different views of what "device"
+ * the filesystem is on
+ */
+ if (ce->ce_dev != (unsigned int) st->st_dev)
+ changed |= INODE_CHANGED;
+#endif
+
+ if (ce->ce_size != (unsigned int) st->st_size)
+ changed |= DATA_CHANGED;
+
+ /* Racily smudged entry? */
+ if (!ce->ce_size) {
+ if (!is_empty_blob_sha1(ce->sha1))
+ changed |= DATA_CHANGED;
+ }
+
+ return changed;
+}
+
+static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
+{
+ return (!S_ISGITLINK(ce->ce_mode) &&
+ istate->timestamp.sec &&
+#ifdef USE_NSEC
+ /* nanosecond timestamped files can also be racy! */
+ (istate->timestamp.sec < ce->ce_mtime.sec ||
+ (istate->timestamp.sec == ce->ce_mtime.sec &&
+ istate->timestamp.nsec <= ce->ce_mtime.nsec))
+#else
+ istate->timestamp.sec <= ce->ce_mtime.sec
+#endif
+ );
+}
+
+int ie_match_stat(const struct index_state *istate,
+ struct cache_entry *ce, struct stat *st,
+ unsigned int options)
+{
+ unsigned int changed;
+ int ignore_valid = options & CE_MATCH_IGNORE_VALID;
+ int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
+ int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
+
+ /*
+ * If it's marked as always valid in the index, it's
+ * valid whatever the checked-out copy says.
+ *
+ * skip-worktree has the same effect with higher precedence
+ */
+ if (!ignore_skip_worktree && ce_skip_worktree(ce))
+ return 0;
+ if (!ignore_valid && (ce->ce_flags & CE_VALID))
+ return 0;
+
+ /*
+ * Intent-to-add entries have not been added, so the index entry
+ * by definition never matches what is in the work tree until it
+ * actually gets added.
+ */
+ if (ce->ce_flags & CE_INTENT_TO_ADD)
+ return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
+
+ changed = ce_match_stat_basic(ce, st);
+
+ /*
+ * Within 1 second of this sequence:
+ * echo xyzzy >file && git-update-index --add file
+ * running this command:
+ * echo frotz >file
+ * would give a falsely clean cache entry. The mtime and
+ * length match the cache, and other stat fields do not change.
+ *
+ * We could detect this at update-index time (the cache entry
+ * being registered/updated records the same time as "now")
+ * and delay the return from git-update-index, but that would
+ * effectively mean we can make at most one commit per second,
+ * which is not acceptable. Instead, we check cache entries
+ * whose mtime are the same as the index file timestamp more
+ * carefully than others.
+ */
+ if (!changed && is_racy_timestamp(istate, ce)) {
+ if (assume_racy_is_modified)
+ changed |= DATA_CHANGED;
+ else
+ changed |= ce_modified_check_fs(ce, st);
+ }
+
+ return changed;
+}
+
+int ie_modified(const struct index_state *istate,
+ struct cache_entry *ce, struct stat *st, unsigned int options)
+{
+ int changed, changed_fs;
+
+ changed = ie_match_stat(istate, ce, st, options);
+ if (!changed)
+ return 0;
+ /*
+ * If the mode or type has changed, there's no point in trying
+ * to refresh the entry - it's not going to match
+ */
+ if (changed & (MODE_CHANGED | TYPE_CHANGED))
+ return changed;
+
+ /*
+ * Immediately after read-tree or update-index --cacheinfo,
+ * the length field is zero, as we have never even read the
+ * lstat(2) information once, and we cannot trust DATA_CHANGED
+ * returned by ie_match_stat() which in turn was returned by
+ * ce_match_stat_basic() to signal that the filesize of the
+ * blob changed. We have to actually go to the filesystem to
+ * see if the contents match, and if so, should answer "unchanged".
+ *
+ * The logic does not apply to gitlinks, as ce_match_stat_basic()
+ * already has checked the actual HEAD from the filesystem in the
+ * subproject. If ie_match_stat() already said it is different,
+ * then we know it is.
+ */
+ if ((changed & DATA_CHANGED) &&
+ (S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
+ return changed;
+
+ changed_fs = ce_modified_check_fs(ce, st);
+ if (changed_fs)
+ return changed | changed_fs;
+ return 0;
+}
+
+int base_name_compare(const char *name1, int len1, int mode1,
+ const char *name2, int len2, int mode2)
+{
+ unsigned char c1, c2;
+ int len = len1 < len2 ? len1 : len2;
+ int cmp;
+
+ cmp = memcmp(name1, name2, len);
+ if (cmp)
+ return cmp;
+ c1 = name1[len];
+ c2 = name2[len];
+ if (!c1 && S_ISDIR(mode1))
+ c1 = '/';
+ if (!c2 && S_ISDIR(mode2))
+ c2 = '/';
+ return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
+}
+
+/*
+ * df_name_compare() is identical to base_name_compare(), except it
+ * compares conflicting directory/file entries as equal. Note that
+ * while a directory name compares as equal to a regular file, they
+ * then individually compare _differently_ to a filename that has
+ * a dot after the basename (because '\0' < '.' < '/').
+ *
+ * This is used by routines that want to traverse the git namespace
+ * but then handle conflicting entries together when possible.
+ */
+int df_name_compare(const char *name1, int len1, int mode1,
+ const char *name2, int len2, int mode2)
+{
+ int len = len1 < len2 ? len1 : len2, cmp;
+ unsigned char c1, c2;
+
+ cmp = memcmp(name1, name2, len);
+ if (cmp)
+ return cmp;
+ /* Directories and files compare equal (same length, same name) */
+ if (len1 == len2)
+ return 0;
+ c1 = name1[len];
+ if (!c1 && S_ISDIR(mode1))
+ c1 = '/';
+ c2 = name2[len];
+ if (!c2 && S_ISDIR(mode2))
+ c2 = '/';
+ if (c1 == '/' && !c2)
+ return 0;
+ if (c2 == '/' && !c1)
+ return 0;
+ return c1 - c2;
+}
+
+int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
+{
+ int len1 = flags1 & CE_NAMEMASK;
+ int len2 = flags2 & CE_NAMEMASK;
+ int len = len1 < len2 ? len1 : len2;
+ int cmp;
+
+ cmp = memcmp(name1, name2, len);
+ if (cmp)
+ return cmp;
+ if (len1 < len2)
+ return -1;
+ if (len1 > len2)
+ return 1;
+
+ /* Compare stages */
+ flags1 &= CE_STAGEMASK;
+ flags2 &= CE_STAGEMASK;
+
+ if (flags1 < flags2)
+ return -1;
+ if (flags1 > flags2)
+ return 1;
+ return 0;
+}
+
+int index_name_pos(const struct index_state *istate, const char *name, int namelen)
+{
+ int first, last;
+
+ first = 0;
+ last = istate->cache_nr;
+ while (last > first) {
+ int next = (last + first) >> 1;
+ struct cache_entry *ce = istate->cache[next];
+ int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
+ if (!cmp)
+ return next;
+ if (cmp < 0) {
+ last = next;
+ continue;
+ }
+ first = next+1;
+ }
+ return -first-1;
+}
+
+/* Remove entry, return true if there are more entries to go.. */
+int remove_index_entry_at(struct index_state *istate, int pos)
+{
+ struct cache_entry *ce = istate->cache[pos];
+
+ record_resolve_undo(istate, ce);
+ remove_name_hash(ce);
+ istate->cache_changed = 1;
+ istate->cache_nr--;
+ if (pos >= istate->cache_nr)
+ return 0;
+ memmove(istate->cache + pos,
+ istate->cache + pos + 1,
+ (istate->cache_nr - pos) * sizeof(struct cache_entry *));
+ return 1;
+}
+
+/*
+ * Remove all cache ententries marked for removal, that is where
+ * CE_REMOVE is set in ce_flags. This is much more effective than
+ * calling remove_index_entry_at() for each entry to be removed.
+ */
+void remove_marked_cache_entries(struct index_state *istate)
+{
+ struct cache_entry **ce_array = istate->cache;
+ unsigned int i, j;
+
+ for (i = j = 0; i < istate->cache_nr; i++) {
+ if (ce_array[i]->ce_flags & CE_REMOVE)
+ remove_name_hash(ce_array[i]);
+ else
+ ce_array[j++] = ce_array[i];
+ }
+ istate->cache_changed = 1;
+ istate->cache_nr = j;
+}
+
+int remove_file_from_index(struct index_state *istate, const char *path)
+{
+ int pos = index_name_pos(istate, path, strlen(path));
+ if (pos < 0)
+ pos = -pos-1;
+ cache_tree_invalidate_path(istate->cache_tree, path);
+ while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
+ remove_index_entry_at(istate, pos);
+ return 0;
+}
+
+static int compare_name(struct cache_entry *ce, const char *path, int namelen)
+{
+ return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
+}
+
+static int index_name_pos_also_unmerged(struct index_state *istate,
+ const char *path, int namelen)
+{
+ int pos = index_name_pos(istate, path, namelen);
+ struct cache_entry *ce;
+
+ if (pos >= 0)
+ return pos;
+
+ /* maybe unmerged? */
+ pos = -1 - pos;
+ if (pos >= istate->cache_nr ||
+ compare_name((ce = istate->cache[pos]), path, namelen))
+ return -1;
+
+ /* order of preference: stage 2, 1, 3 */
+ if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
+ ce_stage((ce = istate->cache[pos + 1])) == 2 &&
+ !compare_name(ce, path, namelen))
+ pos++;
+ return pos;
+}
+
+static int different_name(struct cache_entry *ce, struct cache_entry *alias)
+{
+ int len = ce_namelen(ce);
+ return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
+}
+
+/*
+ * If we add a filename that aliases in the cache, we will use the
+ * name that we already have - but we don't want to update the same
+ * alias twice, because that implies that there were actually two
+ * different files with aliasing names!
+ *
+ * So we use the CE_ADDED flag to verify that the alias was an old
+ * one before we accept it as
+ */
+static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
+{
+ int len;
+ struct cache_entry *new;
+
+ if (alias->ce_flags & CE_ADDED)
+ die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
+
+ /* Ok, create the new entry using the name of the existing alias */
+ len = ce_namelen(alias);
+ new = xcalloc(1, cache_entry_size(len));
+ memcpy(new->name, alias->name, len);
+ copy_cache_entry(new, ce);
+ free(ce);
+ return new;
+}
+
+static void record_intent_to_add(struct cache_entry *ce)
+{
+ unsigned char sha1[20];
+ if (write_sha1_file("", 0, blob_type, sha1))
+ die("cannot create an empty blob in the object database");
+ hashcpy(ce->sha1, sha1);
+}
+
+int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
+{
+ int size, namelen, was_same;
+ mode_t st_mode = st->st_mode;
+ struct cache_entry *ce, *alias;
+ unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY;
+ int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
+ int pretend = flags & ADD_CACHE_PRETEND;
+ int intent_only = flags & ADD_CACHE_INTENT;
+ int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
+ (intent_only ? ADD_CACHE_NEW_ONLY : 0));
+
+ if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
+ return error("%s: can only add regular files, symbolic links or git-directories", path);
+
+ namelen = strlen(path);
+ if (S_ISDIR(st_mode)) {
+ while (namelen && path[namelen-1] == '/')
+ namelen--;
+ }
+ size = cache_entry_size(namelen);
+ ce = xcalloc(1, size);
+ memcpy(ce->name, path, namelen);
+ ce->ce_flags = namelen;
+ if (!intent_only)
+ fill_stat_cache_info(ce, st);
+ else
+ ce->ce_flags |= CE_INTENT_TO_ADD;
+
+ if (trust_executable_bit && has_symlinks)
+ ce->ce_mode = create_ce_mode(st_mode);
+ else {
+ /* If there is an existing entry, pick the mode bits and type
+ * from it, otherwise assume unexecutable regular file.
+ */
+ struct cache_entry *ent;
+ int pos = index_name_pos_also_unmerged(istate, path, namelen);
+
+ ent = (0 <= pos) ? istate->cache[pos] : NULL;
+ ce->ce_mode = ce_mode_from_stat(ent, st_mode);
+ }
+
+ alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
+ if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
+ /* Nothing changed, really */
+ free(ce);
+ if (!S_ISGITLINK(alias->ce_mode))
+ ce_mark_uptodate(alias);
+ alias->ce_flags |= CE_ADDED;
+ return 0;
+ }
+ if (!intent_only) {
+ if (index_path(ce->sha1, path, st, 1))
+ return error("unable to index file %s", path);
+ } else
+ record_intent_to_add(ce);
+
+ if (ignore_case && alias && different_name(ce, alias))
+ ce = create_alias_ce(ce, alias);
+ ce->ce_flags |= CE_ADDED;
+
+ /* It was suspected to be racily clean, but it turns out to be Ok */
+ was_same = (alias &&
+ !ce_stage(alias) &&
+ !hashcmp(alias->sha1, ce->sha1) &&
+ ce->ce_mode == alias->ce_mode);
+
+ if (pretend)
+ ;
+ else if (add_index_entry(istate, ce, add_option))
+ return error("unable to add %s to index",path);
+ if (verbose && !was_same)
+ printf("add '%s'\n", path);
+ return 0;
+}
+
+int add_file_to_index(struct index_state *istate, const char *path, int flags)
+{
+ struct stat st;
+ if (lstat(path, &st))
+ die_errno("unable to stat '%s'", path);
+ return add_to_index(istate, path, &st, flags);
+}
+
+struct cache_entry *make_cache_entry(unsigned int mode,
+ const unsigned char *sha1, const char *path, int stage,
+ int refresh)
+{
+ int size, len;
+ struct cache_entry *ce;
+
+ if (!verify_path(path)) {
+ error("Invalid path '%s'", path);
+ return NULL;
+ }
+
+ len = strlen(path);
+ size = cache_entry_size(len);
+ ce = xcalloc(1, size);
+
+ hashcpy(ce->sha1, sha1);
+ memcpy(ce->name, path, len);
+ ce->ce_flags = create_ce_flags(len, stage);
+ ce->ce_mode = create_ce_mode(mode);
+
+ if (refresh)
+ return refresh_cache_entry(ce, 0);
+
+ return ce;
+}
+
+int ce_same_name(struct cache_entry *a, struct cache_entry *b)
+{
+ int len = ce_namelen(a);
+ return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
+}
+
+int ce_path_match(const struct cache_entry *ce, const char **pathspec)
+{
+ const char *match, *name;
+ int len;
+
+ if (!pathspec)
+ return 1;
+
+ len = ce_namelen(ce);
+ name = ce->name;
+ while ((match = *pathspec++) != NULL) {
+ int matchlen = strlen(match);
+ if (matchlen > len)
+ continue;
+ if (memcmp(name, match, matchlen))
+ continue;
+ if (matchlen && name[matchlen-1] == '/')
+ return 1;
+ if (name[matchlen] == '/' || !name[matchlen])
+ return 1;
+ if (!matchlen)
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * We fundamentally don't like some paths: we don't want
+ * dot or dot-dot anywhere, and for obvious reasons don't
+ * want to recurse into ".git" either.
+ *
+ * Also, we don't want double slashes or slashes at the
+ * end that can make pathnames ambiguous.
+ */
+static int verify_dotfile(const char *rest)
+{
+ /*
+ * The first character was '.', but that
+ * has already been discarded, we now test
+ * the rest.
+ */
+ switch (*rest) {
+ /* "." is not allowed */
+ case '\0': case '/':
+ return 0;
+
+ /*
+ * ".git" followed by NUL or slash is bad. This
+ * shares the path end test with the ".." case.
+ */
+ case 'g':
+ if (rest[1] != 'i')
+ break;
+ if (rest[2] != 't')
+ break;
+ rest += 2;
+ /* fallthrough */
+ case '.':
+ if (rest[1] == '\0' || rest[1] == '/')
+ return 0;
+ }
+ return 1;
+}
+
+int verify_path(const char *path)
+{
+ char c;
+
+ goto inside;
+ for (;;) {
+ if (!c)
+ return 1;
+ if (c == '/') {
+inside:
+ c = *path++;
+ switch (c) {
+ default:
+ continue;
+ case '/': case '\0':
+ break;
+ case '.':
+ if (verify_dotfile(path))
+ continue;
+ }
+ return 0;
+ }
+ c = *path++;
+ }
+}
+
+/*
+ * Do we have another file that has the beginning components being a
+ * proper superset of the name we're trying to add?
+ */
+static int has_file_name(struct index_state *istate,
+ const struct cache_entry *ce, int pos, int ok_to_replace)
+{
+ int retval = 0;
+ int len = ce_namelen(ce);
+ int stage = ce_stage(ce);
+ const char *name = ce->name;
+
+ while (pos < istate->cache_nr) {
+ struct cache_entry *p = istate->cache[pos++];
+
+ if (len >= ce_namelen(p))
+ break;
+ if (memcmp(name, p->name, len))
+ break;
+ if (ce_stage(p) != stage)
+ continue;
+ if (p->name[len] != '/')
+ continue;
+ if (p->ce_flags & CE_REMOVE)
+ continue;
+ retval = -1;
+ if (!ok_to_replace)
+ break;
+ remove_index_entry_at(istate, --pos);
+ }
+ return retval;
+}
+
+/*
+ * Do we have another file with a pathname that is a proper
+ * subset of the name we're trying to add?
+ */
+static int has_dir_name(struct index_state *istate,
+ const struct cache_entry *ce, int pos, int ok_to_replace)
+{
+ int retval = 0;
+ int stage = ce_stage(ce);
+ const char *name = ce->name;
+ const char *slash = name + ce_namelen(ce);
+
+ for (;;) {
+ int len;
+
+ for (;;) {
+ if (*--slash == '/')
+ break;
+ if (slash <= ce->name)
+ return retval;
+ }
+ len = slash - name;
+
+ pos = index_name_pos(istate, name, create_ce_flags(len, stage));
+ if (pos >= 0) {
+ /*
+ * Found one, but not so fast. This could
+ * be a marker that says "I was here, but
+ * I am being removed". Such an entry is
+ * not a part of the resulting tree, and
+ * it is Ok to have a directory at the same
+ * path.
+ */
+ if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
+ retval = -1;
+ if (!ok_to_replace)
+ break;
+ remove_index_entry_at(istate, pos);
+ continue;
+ }
+ }
+ else
+ pos = -pos-1;
+
+ /*
+ * Trivial optimization: if we find an entry that
+ * already matches the sub-directory, then we know
+ * we're ok, and we can exit.
+ */
+ while (pos < istate->cache_nr) {
+ struct cache_entry *p = istate->cache[pos];
+ if ((ce_namelen(p) <= len) ||
+ (p->name[len] != '/') ||
+ memcmp(p->name, name, len))
+ break; /* not our subdirectory */
+ if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
+ /*
+ * p is at the same stage as our entry, and
+ * is a subdirectory of what we are looking
+ * at, so we cannot have conflicts at our
+ * level or anything shorter.
+ */
+ return retval;
+ pos++;
+ }
+ }
+ return retval;
+}
+
+/* We may be in a situation where we already have path/file and path
+ * is being added, or we already have path and path/file is being
+ * added. Either one would result in a nonsense tree that has path
+ * twice when git-write-tree tries to write it out. Prevent it.
+ *
+ * If ok-to-replace is specified, we remove the conflicting entries
+ * from the cache so the caller should recompute the insert position.
+ * When this happens, we return non-zero.
+ */
+static int check_file_directory_conflict(struct index_state *istate,
+ const struct cache_entry *ce,
+ int pos, int ok_to_replace)
+{
+ int retval;
+
+ /*
+ * When ce is an "I am going away" entry, we allow it to be added
+ */
+ if (ce->ce_flags & CE_REMOVE)
+ return 0;
+
+ /*
+ * We check if the path is a sub-path of a subsequent pathname
+ * first, since removing those will not change the position
+ * in the array.
+ */
+ retval = has_file_name(istate, ce, pos, ok_to_replace);
+
+ /*
+ * Then check if the path might have a clashing sub-directory
+ * before it.
+ */
+ return retval + has_dir_name(istate, ce, pos, ok_to_replace);
+}
+
+static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
+{
+ int pos;
+ int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
+ int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
+ int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
+ int new_only = option & ADD_CACHE_NEW_ONLY;
+
+ cache_tree_invalidate_path(istate->cache_tree, ce->name);
+ pos = index_name_pos(istate, ce->name, ce->ce_flags);
+
+ /* existing match? Just replace it. */
+ if (pos >= 0) {
+ if (!new_only)
+ replace_index_entry(istate, pos, ce);
+ return 0;
+ }
+ pos = -pos-1;
+
+ /*
+ * Inserting a merged entry ("stage 0") into the index
+ * will always replace all non-merged entries..
+ */
+ if (pos < istate->cache_nr && ce_stage(ce) == 0) {
+ while (ce_same_name(istate->cache[pos], ce)) {
+ ok_to_add = 1;
+ if (!remove_index_entry_at(istate, pos))
+ break;
+ }
+ }
+
+ if (!ok_to_add)
+ return -1;
+ if (!verify_path(ce->name))
+ return error("Invalid path '%s'", ce->name);
+
+ if (!skip_df_check &&
+ check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
+ if (!ok_to_replace)
+ return error("'%s' appears as both a file and as a directory",
+ ce->name);
+ pos = index_name_pos(istate, ce->name, ce->ce_flags);
+ pos = -pos-1;
+ }
+ return pos + 1;
+}
+
+int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
+{
+ int pos;
+
+ if (option & ADD_CACHE_JUST_APPEND)
+ pos = istate->cache_nr;
+ else {
+ int ret;
+ ret = add_index_entry_with_check(istate, ce, option);
+ if (ret <= 0)
+ return ret;
+ pos = ret - 1;
+ }
+
+ /* Make sure the array is big enough .. */
+ if (istate->cache_nr == istate->cache_alloc) {
+ istate->cache_alloc = alloc_nr(istate->cache_alloc);
+ istate->cache = xrealloc(istate->cache,
+ istate->cache_alloc * sizeof(struct cache_entry *));
+ }
+
+ /* Add it in.. */
+ istate->cache_nr++;
+ if (istate->cache_nr > pos + 1)
+ memmove(istate->cache + pos + 1,
+ istate->cache + pos,
+ (istate->cache_nr - pos - 1) * sizeof(ce));
+ set_index_entry(istate, pos, ce);
+ istate->cache_changed = 1;
+ return 0;
+}
+
+/*
+ * "refresh" does not calculate a new sha1 file or bring the
+ * cache up-to-date for mode/content changes. But what it
+ * _does_ do is to "re-match" the stat information of a file
+ * with the cache, so that you can refresh the cache for a
+ * file that hasn't been changed but where the stat entry is
+ * out of date.
+ *
+ * For example, you'd want to do this after doing a "git-read-tree",
+ * to link up the stat cache details with the proper files.
+ */
+static struct cache_entry *refresh_cache_ent(struct index_state *istate,
+ struct cache_entry *ce,
+ unsigned int options, int *err)
+{
+ struct stat st;
+ struct cache_entry *updated;
+ int changed, size;
+ int ignore_valid = options & CE_MATCH_IGNORE_VALID;
+ int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
+
+ if (ce_uptodate(ce))
+ return ce;
+
+ /*
+ * CE_VALID or CE_SKIP_WORKTREE means the user promised us
+ * that the change to the work tree does not matter and told
+ * us not to worry.
+ */
+ if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
+ ce_mark_uptodate(ce);
+ return ce;
+ }
+ if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
+ ce_mark_uptodate(ce);
+ return ce;
+ }
+
+ if (lstat(ce->name, &st) < 0) {
+ if (err)
+ *err = errno;
+ return NULL;
+ }
+
+ changed = ie_match_stat(istate, ce, &st, options);
+ if (!changed) {
+ /*
+ * The path is unchanged. If we were told to ignore
+ * valid bit, then we did the actual stat check and
+ * found that the entry is unmodified. If the entry
+ * is not marked VALID, this is the place to mark it
+ * valid again, under "assume unchanged" mode.
+ */
+ if (ignore_valid && assume_unchanged &&
+ !(ce->ce_flags & CE_VALID))
+ ; /* mark this one VALID again */
+ else {
+ /*
+ * We do not mark the index itself "modified"
+ * because CE_UPTODATE flag is in-core only;
+ * we are not going to write this change out.
+ */
+ if (!S_ISGITLINK(ce->ce_mode))
+ ce_mark_uptodate(ce);
+ return ce;
+ }
+ }
+
+ if (ie_modified(istate, ce, &st, options)) {
+ if (err)
+ *err = EINVAL;
+ return NULL;
+ }
+
+ size = ce_size(ce);
+ updated = xmalloc(size);
+ memcpy(updated, ce, size);
+ fill_stat_cache_info(updated, &st);
+ /*
+ * If ignore_valid is not set, we should leave CE_VALID bit
+ * alone. Otherwise, paths marked with --no-assume-unchanged
+ * (i.e. things to be edited) will reacquire CE_VALID bit
+ * automatically, which is not really what we want.
+ */
+ if (!ignore_valid && assume_unchanged &&
+ !(ce->ce_flags & CE_VALID))
+ updated->ce_flags &= ~CE_VALID;
+
+ return updated;
+}
+
+static void show_file(const char * fmt, const char * name, int in_porcelain,
+ int * first, char *header_msg)
+{
+ if (in_porcelain && *first && header_msg) {
+ printf("%s\n", header_msg);
+ *first=0;
+ }
+ printf(fmt, name);
+}
+
+int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec,
+ char *seen, char *header_msg)
+{
+ int i;
+ int has_errors = 0;
+ int really = (flags & REFRESH_REALLY) != 0;
+ int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
+ int quiet = (flags & REFRESH_QUIET) != 0;
+ int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
+ int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
+ int first = 1;
+ int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
+ unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
+ const char *needs_update_fmt;
+ const char *needs_merge_fmt;
+
+ needs_update_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
+ needs_merge_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
+ for (i = 0; i < istate->cache_nr; i++) {
+ struct cache_entry *ce, *new;
+ int cache_errno = 0;
+
+ ce = istate->cache[i];
+ if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
+ continue;
+
+ if (ce_stage(ce)) {
+ while ((i < istate->cache_nr) &&
+ ! strcmp(istate->cache[i]->name, ce->name))
+ i++;
+ i--;
+ if (allow_unmerged)
+ continue;
+ show_file(needs_merge_fmt, ce->name, in_porcelain, &first, header_msg);
+ has_errors = 1;
+ continue;
+ }
+
+ if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
+ continue;
+
+ new = refresh_cache_ent(istate, ce, options, &cache_errno);
+ if (new == ce)
+ continue;
+ if (!new) {
+ if (not_new && cache_errno == ENOENT)
+ continue;
+ if (really && cache_errno == EINVAL) {
+ /* If we are doing --really-refresh that
+ * means the index is not valid anymore.
+ */
+ ce->ce_flags &= ~CE_VALID;
+ istate->cache_changed = 1;
+ }
+ if (quiet)
+ continue;
+ show_file(needs_update_fmt, ce->name, in_porcelain, &first, header_msg);
+ has_errors = 1;
+ continue;
+ }
+
+ replace_index_entry(istate, i, new);
+ }
+ return has_errors;
+}
+
+static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
+{
+ return refresh_cache_ent(&the_index, ce, really, NULL);
+}
+
+static int verify_hdr(struct cache_header *hdr, unsigned long size)
+{
+ git_SHA_CTX c;
+ unsigned char sha1[20];
+
+ if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
+ return error("bad signature");
+ if (hdr->hdr_version != htonl(2) && hdr->hdr_version != htonl(3))
+ return error("bad index version");
+ git_SHA1_Init(&c);
+ git_SHA1_Update(&c, hdr, size - 20);
+ git_SHA1_Final(sha1, &c);
+ if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
+ return error("bad index file sha1 signature");
+ return 0;
+}
+
+static int read_index_extension(struct index_state *istate,
+ const char *ext, void *data, unsigned long sz)
+{
+ switch (CACHE_EXT(ext)) {
+ case CACHE_EXT_TREE:
+ istate->cache_tree = cache_tree_read(data, sz);
+ break;
+ case CACHE_EXT_RESOLVE_UNDO:
+ istate->resolve_undo = resolve_undo_read(data, sz);
+ break;
+ default:
+ if (*ext < 'A' || 'Z' < *ext)
+ return error("index uses %.4s extension, which we do not understand",
+ ext);
+ fprintf(stderr, "ignoring %.4s extension\n", ext);
+ break;
+ }
+ return 0;
+}
+
+int read_index(struct index_state *istate)
+{
+ return read_index_from(istate, get_index_file());
+}
+
+static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
+{
+ size_t len;
+ const char *name;
+
+ ce->ce_ctime.sec = ntohl(ondisk->ctime.sec);
+ ce->ce_mtime.sec = ntohl(ondisk->mtime.sec);
+ ce->ce_ctime.nsec = ntohl(ondisk->ctime.nsec);
+ ce->ce_mtime.nsec = ntohl(ondisk->mtime.nsec);
+ ce->ce_dev = ntohl(ondisk->dev);
+ ce->ce_ino = ntohl(ondisk->ino);
+ ce->ce_mode = ntohl(ondisk->mode);
+ ce->ce_uid = ntohl(ondisk->uid);
+ ce->ce_gid = ntohl(ondisk->gid);
+ ce->ce_size = ntohl(ondisk->size);
+ /* On-disk flags are just 16 bits */
+ ce->ce_flags = ntohs(ondisk->flags);
+
+ hashcpy(ce->sha1, ondisk->sha1);
+
+ len = ce->ce_flags & CE_NAMEMASK;
+
+ if (ce->ce_flags & CE_EXTENDED) {
+ struct ondisk_cache_entry_extended *ondisk2;
+ int extended_flags;
+ ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
+ extended_flags = ntohs(ondisk2->flags2) << 16;
+ /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
+ if (extended_flags & ~CE_EXTENDED_FLAGS)
+ die("Unknown index entry format %08x", extended_flags);
+ ce->ce_flags |= extended_flags;
+ name = ondisk2->name;
+ }
+ else
+ name = ondisk->name;
+
+ if (len == CE_NAMEMASK)
+ len = strlen(name);
+ /*
+ * NEEDSWORK: If the original index is crafted, this copy could
+ * go unchecked.
+ */
+ memcpy(ce->name, name, len + 1);
+}
+
+static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
+{
+ long per_entry;
+
+ per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
+
+ /*
+ * Alignment can cause differences. This should be "alignof", but
+ * since that's a gcc'ism, just use the size of a pointer.
+ */
+ per_entry += sizeof(void *);
+ return ondisk_size + entries*per_entry;
+}
+
+/* remember to discard_cache() before reading a different cache! */
+int read_index_from(struct index_state *istate, const char *path)
+{
+ int fd, i;
+ struct stat st;
+ unsigned long src_offset, dst_offset;
+ struct cache_header *hdr;
+ void *mmap;
+ size_t mmap_size;
+
+ errno = EBUSY;
+ if (istate->initialized)
+ return istate->cache_nr;
+
+ errno = ENOENT;
+ istate->timestamp.sec = 0;
+ istate->timestamp.nsec = 0;
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ if (errno == ENOENT)
+ return 0;
+ die_errno("index file open failed");
+ }
+
+ if (fstat(fd, &st))
+ die_errno("cannot stat the open index");
+
+ errno = EINVAL;
+ mmap_size = xsize_t(st.st_size);
+ if (mmap_size < sizeof(struct cache_header) + 20)
+ die("index file smaller than expected");
+
+ mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+ close(fd);
+ if (mmap == MAP_FAILED)
+ die_errno("unable to map index file");
+
+ hdr = mmap;
+ if (verify_hdr(hdr, mmap_size) < 0)
+ goto unmap;
+
+ istate->cache_nr = ntohl(hdr->hdr_entries);
+ istate->cache_alloc = alloc_nr(istate->cache_nr);
+ istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
+
+ /*
+ * The disk format is actually larger than the in-memory format,
+ * due to space for nsec etc, so even though the in-memory one
+ * has room for a few more flags, we can allocate using the same
+ * index size
+ */
+ istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
+ istate->initialized = 1;
+
+ src_offset = sizeof(*hdr);
+ dst_offset = 0;
+ for (i = 0; i < istate->cache_nr; i++) {
+ struct ondisk_cache_entry *disk_ce;
+ struct cache_entry *ce;
+
+ disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
+ ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
+ convert_from_disk(disk_ce, ce);
+ set_index_entry(istate, i, ce);
+
+ src_offset += ondisk_ce_size(ce);
+ dst_offset += ce_size(ce);
+ }
+ istate->timestamp.sec = st.st_mtime;
+ istate->timestamp.nsec = ST_MTIME_NSEC(st);
+
+ while (src_offset <= mmap_size - 20 - 8) {
+ /* After an array of active_nr index entries,
+ * there can be arbitrary number of extended
+ * sections, each of which is prefixed with
+ * extension name (4-byte) and section length
+ * in 4-byte network byte order.
+ */
+ uint32_t extsize;
+ memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
+ extsize = ntohl(extsize);
+ if (read_index_extension(istate,
+ (const char *) mmap + src_offset,
+ (char *) mmap + src_offset + 8,
+ extsize) < 0)
+ goto unmap;
+ src_offset += 8;
+ src_offset += extsize;
+ }
+ munmap(mmap, mmap_size);
+ return istate->cache_nr;
+
+unmap:
+ munmap(mmap, mmap_size);
+ errno = EINVAL;
+ die("index file corrupt");
+}
+
+int is_index_unborn(struct index_state *istate)
+{
+ return (!istate->cache_nr && !istate->alloc && !istate->timestamp.sec);
+}
+
+int discard_index(struct index_state *istate)
+{
+ resolve_undo_clear_index(istate);
+ istate->cache_nr = 0;
+ istate->cache_changed = 0;
+ istate->timestamp.sec = 0;
+ istate->timestamp.nsec = 0;
+ istate->name_hash_initialized = 0;
+ free_hash(&istate->name_hash);
+ cache_tree_free(&(istate->cache_tree));
+ free(istate->alloc);
+ istate->alloc = NULL;
+ istate->initialized = 0;
+
+ /* no need to throw away allocated active_cache */
+ return 0;
+}
+
+int unmerged_index(const struct index_state *istate)
+{
+ int i;
+ for (i = 0; i < istate->cache_nr; i++) {
+ if (ce_stage(istate->cache[i]))
+ return 1;
+ }
+ return 0;
+}
+
+#define WRITE_BUFFER_SIZE 8192
+static unsigned char write_buffer[WRITE_BUFFER_SIZE];
+static unsigned long write_buffer_len;
+
+static int ce_write_flush(git_SHA_CTX *context, int fd)
+{
+ unsigned int buffered = write_buffer_len;
+ if (buffered) {
+ git_SHA1_Update(context, write_buffer, buffered);
+ if (write_in_full(fd, write_buffer, buffered) != buffered)
+ return -1;
+ write_buffer_len = 0;
+ }
+ return 0;
+}
+
+static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
+{
+ while (len) {
+ unsigned int buffered = write_buffer_len;
+ unsigned int partial = WRITE_BUFFER_SIZE - buffered;
+ if (partial > len)
+ partial = len;
+ memcpy(write_buffer + buffered, data, partial);
+ buffered += partial;
+ if (buffered == WRITE_BUFFER_SIZE) {
+ write_buffer_len = buffered;
+ if (ce_write_flush(context, fd))
+ return -1;
+ buffered = 0;
+ }
+ write_buffer_len = buffered;
+ len -= partial;
+ data = (char *) data + partial;
+ }
+ return 0;
+}
+
+static int write_index_ext_header(git_SHA_CTX *context, int fd,
+ unsigned int ext, unsigned int sz)
+{
+ ext = htonl(ext);
+ sz = htonl(sz);
+ return ((ce_write(context, fd, &ext, 4) < 0) ||
+ (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
+}
+
+static int ce_flush(git_SHA_CTX *context, int fd)
+{
+ unsigned int left = write_buffer_len;
+
+ if (left) {
+ write_buffer_len = 0;
+ git_SHA1_Update(context, write_buffer, left);
+ }
+
+ /* Flush first if not enough space for SHA1 signature */
+ if (left + 20 > WRITE_BUFFER_SIZE) {
+ if (write_in_full(fd, write_buffer, left) != left)
+ return -1;
+ left = 0;
+ }
+
+ /* Append the SHA1 signature at the end */
+ git_SHA1_Final(write_buffer + left, context);
+ left += 20;
+ return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
+}
+
+static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
+{
+ /*
+ * The only thing we care about in this function is to smudge the
+ * falsely clean entry due to touch-update-touch race, so we leave
+ * everything else as they are. We are called for entries whose
+ * ce_mtime match the index file mtime.
+ *
+ * Note that this actually does not do much for gitlinks, for
+ * which ce_match_stat_basic() always goes to the actual
+ * contents. The caller checks with is_racy_timestamp() which
+ * always says "no" for gitlinks, so we are not called for them ;-)
+ */
+ struct stat st;
+
+ if (lstat(ce->name, &st) < 0)
+ return;
+ if (ce_match_stat_basic(ce, &st))
+ return;
+ if (ce_modified_check_fs(ce, &st)) {
+ /* This is "racily clean"; smudge it. Note that this
+ * is a tricky code. At first glance, it may appear
+ * that it can break with this sequence:
+ *
+ * $ echo xyzzy >frotz
+ * $ git-update-index --add frotz
+ * $ : >frotz
+ * $ sleep 3
+ * $ echo filfre >nitfol
+ * $ git-update-index --add nitfol
+ *
+ * but it does not. When the second update-index runs,
+ * it notices that the entry "frotz" has the same timestamp
+ * as index, and if we were to smudge it by resetting its
+ * size to zero here, then the object name recorded
+ * in index is the 6-byte file but the cached stat information
+ * becomes zero --- which would then match what we would
+ * obtain from the filesystem next time we stat("frotz").
+ *
+ * However, the second update-index, before calling
+ * this function, notices that the cached size is 6
+ * bytes and what is on the filesystem is an empty
+ * file, and never calls us, so the cached size information
+ * for "frotz" stays 6 which does not match the filesystem.
+ */
+ ce->ce_size = 0;
+ }
+}
+
+static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
+{
+ int size = ondisk_ce_size(ce);
+ struct ondisk_cache_entry *ondisk = xcalloc(1, size);
+ char *name;
+
+ ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
+ ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
+ ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
+ ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
+ ondisk->dev = htonl(ce->ce_dev);
+ ondisk->ino = htonl(ce->ce_ino);
+ ondisk->mode = htonl(ce->ce_mode);
+ ondisk->uid = htonl(ce->ce_uid);
+ ondisk->gid = htonl(ce->ce_gid);
+ ondisk->size = htonl(ce->ce_size);
+ hashcpy(ondisk->sha1, ce->sha1);
+ ondisk->flags = htons(ce->ce_flags);
+ if (ce->ce_flags & CE_EXTENDED) {
+ struct ondisk_cache_entry_extended *ondisk2;
+ ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
+ ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
+ name = ondisk2->name;
+ }
+ else
+ name = ondisk->name;
+ memcpy(name, ce->name, ce_namelen(ce));
+
+ return ce_write(c, fd, ondisk, size);
+}
+
+int write_index(struct index_state *istate, int newfd)
+{
+ git_SHA_CTX c;
+ struct cache_header hdr;
+ int i, err, removed, extended;
+ struct cache_entry **cache = istate->cache;
+ int entries = istate->cache_nr;
+ struct stat st;
+
+ for (i = removed = extended = 0; i < entries; i++) {
+ if (cache[i]->ce_flags & CE_REMOVE)
+ removed++;
+
+ /* reduce extended entries if possible */
+ cache[i]->ce_flags &= ~CE_EXTENDED;
+ if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
+ extended++;
+ cache[i]->ce_flags |= CE_EXTENDED;
+ }
+ }
+
+ hdr.hdr_signature = htonl(CACHE_SIGNATURE);
+ /* for extended format, increase version so older git won't try to read it */
+ hdr.hdr_version = htonl(extended ? 3 : 2);
+ hdr.hdr_entries = htonl(entries - removed);
+
+ git_SHA1_Init(&c);
+ if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
+ return -1;
+
+ for (i = 0; i < entries; i++) {
+ struct cache_entry *ce = cache[i];
+ if (ce->ce_flags & CE_REMOVE)
+ continue;
+ if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
+ ce_smudge_racily_clean_entry(ce);
+ if (ce_write_entry(&c, newfd, ce) < 0)
+ return -1;
+ }
+
+ /* Write extension data here */
+ if (istate->cache_tree) {
+ struct strbuf sb = STRBUF_INIT;
+
+ cache_tree_write(&sb, istate->cache_tree);
+ err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
+ || ce_write(&c, newfd, sb.buf, sb.len) < 0;
+ strbuf_release(&sb);
+ if (err)
+ return -1;
+ }
+ if (istate->resolve_undo) {
+ struct strbuf sb = STRBUF_INIT;
+
+ resolve_undo_write(&sb, istate->resolve_undo);
+ err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
+ sb.len) < 0
+ || ce_write(&c, newfd, sb.buf, sb.len) < 0;
+ strbuf_release(&sb);
+ if (err)
+ return -1;
+ }
+
+ if (ce_flush(&c, newfd) || fstat(newfd, &st))
+ return -1;
+ istate->timestamp.sec = (unsigned int)st.st_mtime;
+ istate->timestamp.nsec = ST_MTIME_NSEC(st);
+ return 0;
+}
+
+/*
+ * Read the index file that is potentially unmerged into given
+ * index_state, dropping any unmerged entries. Returns true if
+ * the index is unmerged. Callers who want to refuse to work
+ * from an unmerged state can call this and check its return value,
+ * instead of calling read_cache().
+ */
+int read_index_unmerged(struct index_state *istate)
+{
+ int i;
+ int unmerged = 0;
+
+ read_index(istate);
+ for (i = 0; i < istate->cache_nr; i++) {
+ struct cache_entry *ce = istate->cache[i];
+ struct cache_entry *new_ce;
+ int size, len;
+
+ if (!ce_stage(ce))
+ continue;
+ unmerged = 1;
+ len = strlen(ce->name);
+ size = cache_entry_size(len);
+ new_ce = xcalloc(1, size);
+ memcpy(new_ce->name, ce->name, len);
+ new_ce->ce_flags = create_ce_flags(len, 0) | CE_CONFLICTED;
+ new_ce->ce_mode = ce->ce_mode;
+ if (add_index_entry(istate, new_ce, 0))
+ return error("%s: cannot drop to stage #0",
+ ce->name);
+ i = index_name_pos(istate, new_ce->name, len);
+ }
+ return unmerged;
+}
+
+/*
+ * Returns 1 if the path is an "other" path with respect to
+ * the index; that is, the path is not mentioned in the index at all,
+ * either as a file, a directory with some files in the index,
+ * or as an unmerged entry.
+ *
+ * We helpfully remove a trailing "/" from directories so that
+ * the output of read_directory can be used as-is.
+ */
+int index_name_is_other(const struct index_state *istate, const char *name,
+ int namelen)
+{
+ int pos;
+ if (namelen && name[namelen - 1] == '/')
+ namelen--;
+ pos = index_name_pos(istate, name, namelen);
+ if (0 <= pos)
+ return 0; /* exact match */
+ pos = -pos - 1;
+ if (pos < istate->cache_nr) {
+ struct cache_entry *ce = istate->cache[pos];
+ if (ce_namelen(ce) == namelen &&
+ !memcmp(ce->name, name, namelen))
+ return 0; /* Yup, this one exists unmerged */
+ }
+ return 1;
+}