Update draft release notes to 1.7.9
[gitweb.git] / read-cache.c
index 3f587110cb9d7be1890b7db68a0bdac35d48cd35..a51bba1b9569d64c348f3affc90ed8640e0e0189 100644 (file)
 #include "dir.h"
 #include "tree.h"
 #include "commit.h"
-#include "diff.h"
-#include "diffcore.h"
-#include "revision.h"
 #include "blob.h"
+#include "resolve-undo.h"
+
+static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
 
 /* Index extensions.
  *
@@ -26,6 +26,7 @@
 
 #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 /* "REUC" */
 
 struct index_state the_index;
 
@@ -91,7 +92,7 @@ static int ce_compare_data(struct cache_entry *ce, struct stat *st)
 
        if (fd >= 0) {
                unsigned char sha1[20];
-               if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
+               if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0))
                        match = hashcmp(sha1, ce->sha1);
                /* index_fd() closed the file descriptor already */
        }
@@ -156,7 +157,7 @@ static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
        return 0;
 }
 
-int is_empty_blob_sha1(const unsigned char *sha1)
+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,
@@ -259,12 +260,17 @@ int ie_match_stat(const struct index_state *istate,
 {
        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;
 
@@ -449,6 +455,7 @@ 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--;
@@ -564,7 +571,7 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st,
        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_RACY_IS_DIRTY;
+       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;
@@ -601,16 +608,40 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st,
                ce->ce_mode = ce_mode_from_stat(ent, st_mode);
        }
 
+       /* When core.ignorecase=true, determine if a directory of the same name but differing
+        * case already exists within the Git repository.  If it does, ensure the directory
+        * case of the file being added to the repository matches (is folded into) the existing
+        * entry's directory case.
+        */
+       if (ignore_case) {
+               const char *startPtr = ce->name;
+               const char *ptr = startPtr;
+               while (*ptr) {
+                       while (*ptr && *ptr != '/')
+                               ++ptr;
+                       if (*ptr == '/') {
+                               struct cache_entry *foundce;
+                               ++ptr;
+                               foundce = index_name_exists(&the_index, ce->name, ptr - ce->name, ignore_case);
+                               if (foundce) {
+                                       memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr);
+                                       startPtr = ptr;
+                               }
+                       }
+               }
+       }
+
        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);
-               ce_mark_uptodate(alias);
+               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))
+               if (index_path(ce->sha1, path, st, HASH_WRITE_OBJECT))
                        return error("unable to index file %s", path);
        } else
                record_intent_to_add(ce);
@@ -638,7 +669,7 @@ int add_file_to_index(struct index_state *istate, const char *path, int flags)
 {
        struct stat st;
        if (lstat(path, &st))
-               die("%s: unable to stat (%s)", path, strerror(errno));
+               die_errno("unable to stat '%s'", path);
        return add_to_index(istate, path, &st, flags);
 }
 
@@ -675,30 +706,9 @@ int ce_same_name(struct cache_entry *a, struct cache_entry *b)
        return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
 }
 
-int ce_path_match(const struct cache_entry *ce, const char **pathspec)
+int ce_path_match(const struct cache_entry *ce, const struct pathspec *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;
+       return match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL);
 }
 
 /*
@@ -716,11 +726,12 @@ static int verify_dotfile(const char *rest)
         * has already been discarded, we now test
         * the rest.
         */
-       switch (*rest) {
+
        /* "." is not allowed */
-       case '\0': case '/':
+       if (*rest == '\0' || is_dir_sep(*rest))
                return 0;
 
+       switch (*rest) {
        /*
         * ".git" followed by  NUL or slash is bad. This
         * shares the path end test with the ".." case.
@@ -733,7 +744,7 @@ static int verify_dotfile(const char *rest)
                rest += 2;
        /* fallthrough */
        case '.':
-               if (rest[1] == '\0' || rest[1] == '/')
+               if (rest[1] == '\0' || is_dir_sep(rest[1]))
                        return 0;
        }
        return 1;
@@ -743,23 +754,19 @@ int verify_path(const char *path)
 {
        char c;
 
+       if (has_dos_drive_prefix(path))
+               return 0;
+
        goto inside;
        for (;;) {
                if (!c)
                        return 1;
-               if (c == '/') {
+               if (is_dir_sep(c)) {
 inside:
                        c = *path++;
-                       switch (c) {
-                       default:
-                               continue;
-                       case '/': case '\0':
-                               break;
-                       case '.':
-                               if (verify_dotfile(path))
-                                       continue;
-                       }
-                       return 0;
+                       if ((c == '.' && !verify_dotfile(path)) ||
+                           is_dir_sep(c) || c == '\0')
+                               return 0;
                }
                c = *path++;
        }
@@ -994,20 +1001,27 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
  */
 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
                                             struct cache_entry *ce,
-                                            unsigned int options, int *err)
+                                            unsigned int options, int *err,
+                                            int *changed_ret)
 {
        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 means the user promised us that the change to
-        * the work tree does not matter and told us not to worry.
+        * 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;
@@ -1020,6 +1034,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
        }
 
        changed = ie_match_stat(istate, ce, &st, options);
+       if (changed_ret)
+               *changed_ret = changed;
        if (!changed) {
                /*
                 * The path is unchanged.  If we were told to ignore
@@ -1037,7 +1053,8 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
                         * because CE_UPTODATE flag is in-core only;
                         * we are not going to write this change out.
                         */
-                       ce_mark_uptodate(ce);
+                       if (!S_ISGITLINK(ce->ce_mode))
+                               ce_mark_uptodate(ce);
                        return ce;
                }
        }
@@ -1065,7 +1082,18 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate,
        return updated;
 }
 
-int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
+static void show_file(const char * fmt, const char * name, int in_porcelain,
+                     int * first, const 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, const char *header_msg)
 {
        int i;
        int has_errors = 0;
@@ -1074,14 +1102,24 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
        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_message;
-
-       needs_update_message = ((flags & REFRESH_SAY_CHANGED)
-                               ? "locally modified" : "needs update");
+       const char *modified_fmt;
+       const char *deleted_fmt;
+       const char *typechange_fmt;
+       const char *added_fmt;
+       const char *unmerged_fmt;
+
+       modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
+       deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
+       typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
+       added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
+       unmerged_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;
+               int changed = 0;
 
                ce = istate->cache[i];
                if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
@@ -1094,7 +1132,7 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
                        i--;
                        if (allow_unmerged)
                                continue;
-                       printf("%s: needs merge\n", ce->name);
+                       show_file(unmerged_fmt, ce->name, in_porcelain, &first, header_msg);
                        has_errors = 1;
                        continue;
                }
@@ -1102,10 +1140,12 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
                if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
                        continue;
 
-               new = refresh_cache_ent(istate, ce, options, &cache_errno);
+               new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
                if (new == ce)
                        continue;
                if (!new) {
+                       const char *fmt;
+
                        if (not_new && cache_errno == ENOENT)
                                continue;
                        if (really && cache_errno == EINVAL) {
@@ -1117,7 +1157,17 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
                        }
                        if (quiet)
                                continue;
-                       printf("%s: %s\n", ce->name, needs_update_message);
+
+                       if (cache_errno == ENOENT)
+                               fmt = deleted_fmt;
+                       else if (ce->ce_flags & CE_INTENT_TO_ADD)
+                               fmt = added_fmt; /* must be before other checks */
+                       else if (changed & TYPE_CHANGED)
+                               fmt = typechange_fmt;
+                       else
+                               fmt = modified_fmt;
+                       show_file(fmt,
+                                 ce->name, in_porcelain, &first, header_msg);
                        has_errors = 1;
                        continue;
                }
@@ -1127,9 +1177,9 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char **p
        return has_errors;
 }
 
-struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
+static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
 {
-       return refresh_cache_ent(&the_index, ce, really, NULL);
+       return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
 }
 
 static int verify_hdr(struct cache_header *hdr, unsigned long size)
@@ -1156,6 +1206,9 @@ static int read_index_extension(struct index_state *istate,
        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",
@@ -1171,29 +1224,18 @@ 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)
+static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk)
 {
+       struct cache_entry *ce;
        size_t len;
        const char *name;
+       unsigned int flags;
 
-       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);
+       flags = ntohs(ondisk->flags);
+       len = flags & CE_NAMEMASK;
 
-       hashcpy(ce->sha1, ondisk->sha1);
-
-       len = ce->ce_flags & CE_NAMEMASK;
-
-       if (ce->ce_flags & CE_EXTENDED) {
+       if (flags & CE_EXTENDED) {
                struct ondisk_cache_entry_extended *ondisk2;
                int extended_flags;
                ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
@@ -1201,7 +1243,7 @@ static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_en
                /* 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;
+               flags |= extended_flags;
                name = ondisk2->name;
        }
        else
@@ -1209,25 +1251,26 @@ static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_en
 
        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;
+       ce = xmalloc(cache_entry_size(len));
+
+       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);
+       ce->ce_flags = flags;
 
-       per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
+       hashcpy(ce->sha1, ondisk->sha1);
 
-       /*
-        * 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;
+       memcpy(ce->name, name, len);
+       ce->name[len] = '\0';
+       return ce;
 }
 
 /* remember to discard_cache() before reading a different cache! */
@@ -1235,7 +1278,7 @@ int read_index_from(struct index_state *istate, const char *path)
 {
        int fd, i;
        struct stat st;
-       unsigned long src_offset, dst_offset;
+       unsigned long src_offset;
        struct cache_header *hdr;
        void *mmap;
        size_t mmap_size;
@@ -1251,11 +1294,11 @@ int read_index_from(struct index_state *istate, const char *path)
        if (fd < 0) {
                if (errno == ENOENT)
                        return 0;
-               die("index file open failed (%s)", strerror(errno));
+               die_errno("index file open failed");
        }
 
        if (fstat(fd, &st))
-               die("cannot stat the open index (%s)", strerror(errno));
+               die_errno("cannot stat the open index");
 
        errno = EINVAL;
        mmap_size = xsize_t(st.st_size);
@@ -1265,7 +1308,7 @@ int read_index_from(struct index_state *istate, const char *path)
        mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        close(fd);
        if (mmap == MAP_FAILED)
-               die("unable to map index file");
+               die_errno("unable to map index file");
 
        hdr = mmap;
        if (verify_hdr(hdr, mmap_size) < 0)
@@ -1274,29 +1317,18 @@ int read_index_from(struct index_state *istate, const char *path)
        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);
+               ce = create_from_disk(disk_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);
@@ -1308,7 +1340,7 @@ int read_index_from(struct index_state *istate, const char *path)
                 * extension name (4-byte) and section length
                 * in 4-byte network byte order.
                 */
-               unsigned long extsize;
+               uint32_t extsize;
                memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
                extsize = ntohl(extsize);
                if (read_index_extension(istate,
@@ -1330,11 +1362,16 @@ int read_index_from(struct index_state *istate, const char *path)
 
 int is_index_unborn(struct index_state *istate)
 {
-       return (!istate->cache_nr && !istate->alloc && !istate->timestamp.sec);
+       return (!istate->cache_nr && !istate->timestamp.sec);
 }
 
 int discard_index(struct index_state *istate)
 {
+       int i;
+
+       for (i = 0; i < istate->cache_nr; i++)
+               free(istate->cache[i]);
+       resolve_undo_clear_index(istate);
        istate->cache_nr = 0;
        istate->cache_changed = 0;
        istate->timestamp.sec = 0;
@@ -1342,8 +1379,6 @@ int discard_index(struct index_state *istate)
        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 */
@@ -1483,6 +1518,7 @@ 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;
+       int result;
 
        ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
        ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
@@ -1506,7 +1542,34 @@ static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
                name = ondisk->name;
        memcpy(name, ce->name, ce_namelen(ce));
 
-       return ce_write(c, fd, ondisk, size);
+       result = ce_write(c, fd, ondisk, size);
+       free(ondisk);
+       return result;
+}
+
+static int has_racy_timestamp(struct index_state *istate)
+{
+       int entries = istate->cache_nr;
+       int i;
+
+       for (i = 0; i < entries; i++) {
+               struct cache_entry *ce = istate->cache[i];
+               if (is_racy_timestamp(istate, ce))
+                       return 1;
+       }
+       return 0;
+}
+
+/*
+ * Opportunisticly update the index but do not complain if we can't
+ */
+void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
+{
+       if ((istate->cache_changed || has_racy_timestamp(istate)) &&
+           !write_index(istate, lockfile->fd))
+               commit_locked_index(lockfile);
+       else
+               rollback_lock_file(lockfile);
 }
 
 int write_index(struct index_state *istate, int newfd)
@@ -1560,6 +1623,17 @@ int write_index(struct index_state *istate, int newfd)
                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;
@@ -1592,9 +1666,8 @@ int read_index_unmerged(struct index_state *istate)
                len = strlen(ce->name);
                size = cache_entry_size(len);
                new_ce = xcalloc(1, size);
-               hashcpy(new_ce->sha1, ce->sha1);
                memcpy(new_ce->name, ce->name, len);
-               new_ce->ce_flags = create_ce_flags(len, 0);
+               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",
@@ -1604,81 +1677,6 @@ int read_index_unmerged(struct index_state *istate)
        return unmerged;
 }
 
-struct update_callback_data
-{
-       int flags;
-       int add_errors;
-};
-
-static void update_callback(struct diff_queue_struct *q,
-                           struct diff_options *opt, void *cbdata)
-{
-       int i;
-       struct update_callback_data *data = cbdata;
-
-       for (i = 0; i < q->nr; i++) {
-               struct diff_filepair *p = q->queue[i];
-               const char *path = p->one->path;
-               switch (p->status) {
-               default:
-                       die("unexpected diff status %c", p->status);
-               case DIFF_STATUS_UNMERGED:
-                       /*
-                        * ADD_CACHE_IGNORE_REMOVAL is unset if "git
-                        * add -u" is calling us, In such a case, a
-                        * missing work tree file needs to be removed
-                        * if there is an unmerged entry at stage #2,
-                        * but such a diff record is followed by
-                        * another with DIFF_STATUS_DELETED (and if
-                        * there is no stage #2, we won't see DELETED
-                        * nor MODIFIED).  We can simply continue
-                        * either way.
-                        */
-                       if (!(data->flags & ADD_CACHE_IGNORE_REMOVAL))
-                               continue;
-                       /*
-                        * Otherwise, it is "git add path" is asking
-                        * to explicitly add it; we fall through.  A
-                        * missing work tree file is an error and is
-                        * caught by add_file_to_index() in such a
-                        * case.
-                        */
-               case DIFF_STATUS_MODIFIED:
-               case DIFF_STATUS_TYPE_CHANGED:
-                       if (add_file_to_index(&the_index, path, data->flags)) {
-                               if (!(data->flags & ADD_CACHE_IGNORE_ERRORS))
-                                       die("updating files failed");
-                               data->add_errors++;
-                       }
-                       break;
-               case DIFF_STATUS_DELETED:
-                       if (data->flags & ADD_CACHE_IGNORE_REMOVAL)
-                               break;
-                       if (!(data->flags & ADD_CACHE_PRETEND))
-                               remove_file_from_index(&the_index, path);
-                       if (data->flags & (ADD_CACHE_PRETEND|ADD_CACHE_VERBOSE))
-                               printf("remove '%s'\n", path);
-                       break;
-               }
-       }
-}
-
-int add_files_to_cache(const char *prefix, const char **pathspec, int flags)
-{
-       struct update_callback_data data;
-       struct rev_info rev;
-       init_revisions(&rev, prefix);
-       setup_revisions(0, NULL, &rev, NULL);
-       rev.prune_data = pathspec;
-       rev.diffopt.output_format = DIFF_FORMAT_CALLBACK;
-       rev.diffopt.format_callback = update_callback;
-       data.flags = flags;
-       data.add_errors = 0;
-       rev.diffopt.format_callback_data = &data;
-       run_diff_files(&rev, DIFF_RACY_IS_MODIFIED);
-       return !!data.add_errors;
-}
-
 /*
  * 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,