verify_path: drop clever fallthrough
[gitweb.git] / unpack-trees.c
index 6e9f75549dde32781d6a2b032ab9edb1b7a5e079..aa15111fefc8ca333edeeeb3ac77a8b946e4c6a5 100644 (file)
@@ -10,6 +10,8 @@
 #include "attr.h"
 #include "split-index.h"
 #include "dir.h"
+#include "submodule.h"
+#include "submodule-config.h"
 
 /*
  * Error messages expected by scripts out of plumbing commands such as
@@ -45,6 +47,9 @@ static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 
        /* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
        "Working tree file '%s' would be removed by sparse checkout update.",
+
+       /* ERROR_WOULD_LOSE_SUBMODULE */
+       "Submodule '%s' cannot checkout new HEAD.",
 };
 
 #define ERRORMSG(o,type) \
@@ -52,46 +57,117 @@ static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
          ? ((o)->msgs[(type)])      \
          : (unpack_plumbing_errors[(type)]) )
 
+static const char *super_prefixed(const char *path)
+{
+       /*
+        * It is necessary and sufficient to have two static buffers
+        * here, as the return value of this function is fed to
+        * error() using the unpack_*_errors[] templates we see above.
+        */
+       static struct strbuf buf[2] = {STRBUF_INIT, STRBUF_INIT};
+       static int super_prefix_len = -1;
+       static unsigned idx = ARRAY_SIZE(buf) - 1;
+
+       if (super_prefix_len < 0) {
+               const char *super_prefix = get_super_prefix();
+               if (!super_prefix) {
+                       super_prefix_len = 0;
+               } else {
+                       int i;
+                       for (i = 0; i < ARRAY_SIZE(buf); i++)
+                               strbuf_addstr(&buf[i], super_prefix);
+                       super_prefix_len = buf[0].len;
+               }
+       }
+
+       if (!super_prefix_len)
+               return path;
+
+       if (++idx >= ARRAY_SIZE(buf))
+               idx = 0;
+
+       strbuf_setlen(&buf[idx], super_prefix_len);
+       strbuf_addstr(&buf[idx], path);
+
+       return buf[idx].buf;
+}
+
 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                                  const char *cmd)
 {
        int i;
        const char **msgs = opts->msgs;
        const char *msg;
-       const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
 
-       if (advice_commit_before_merge)
-               msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
-                       "Please, commit your changes or stash them before you can %s.";
+       if (!strcmp(cmd, "checkout"))
+               msg = advice_commit_before_merge
+                     ? _("Your local changes to the following files would be overwritten by checkout:\n%%s"
+                         "Please commit your changes or stash them before you switch branches.")
+                     : _("Your local changes to the following files would be overwritten by checkout:\n%%s");
+       else if (!strcmp(cmd, "merge"))
+               msg = advice_commit_before_merge
+                     ? _("Your local changes to the following files would be overwritten by merge:\n%%s"
+                         "Please commit your changes or stash them before you merge.")
+                     : _("Your local changes to the following files would be overwritten by merge:\n%%s");
        else
-               msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
+               msg = advice_commit_before_merge
+                     ? _("Your local changes to the following files would be overwritten by %s:\n%%s"
+                         "Please commit your changes or stash them before you %s.")
+                     : _("Your local changes to the following files would be overwritten by %s:\n%%s");
        msgs[ERROR_WOULD_OVERWRITE] = msgs[ERROR_NOT_UPTODATE_FILE] =
-               xstrfmt(msg, cmd, cmd2);
+               xstrfmt(msg, cmd, cmd);
 
        msgs[ERROR_NOT_UPTODATE_DIR] =
-               "Updating the following directories would lose untracked files in it:\n%s";
-
-       if (advice_commit_before_merge)
-               msg = "The following untracked working tree files would be %s by %s:\n%%s"
-                       "Please move or remove them before you can %s.";
+               _("Updating the following directories would lose untracked files in them:\n%s");
+
+       if (!strcmp(cmd, "checkout"))
+               msg = advice_commit_before_merge
+                     ? _("The following untracked working tree files would be removed by checkout:\n%%s"
+                         "Please move or remove them before you switch branches.")
+                     : _("The following untracked working tree files would be removed by checkout:\n%%s");
+       else if (!strcmp(cmd, "merge"))
+               msg = advice_commit_before_merge
+                     ? _("The following untracked working tree files would be removed by merge:\n%%s"
+                         "Please move or remove them before you merge.")
+                     : _("The following untracked working tree files would be removed by merge:\n%%s");
        else
-               msg = "The following untracked working tree files would be %s by %s:\n%%s";
-
-       msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = xstrfmt(msg, "removed", cmd, cmd2);
-       msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = xstrfmt(msg, "overwritten", cmd, cmd2);
+               msg = advice_commit_before_merge
+                     ? _("The following untracked working tree files would be removed by %s:\n%%s"
+                         "Please move or remove them before you %s.")
+                     : _("The following untracked working tree files would be removed by %s:\n%%s");
+       msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = xstrfmt(msg, cmd, cmd);
+
+       if (!strcmp(cmd, "checkout"))
+               msg = advice_commit_before_merge
+                     ? _("The following untracked working tree files would be overwritten by checkout:\n%%s"
+                         "Please move or remove them before you switch branches.")
+                     : _("The following untracked working tree files would be overwritten by checkout:\n%%s");
+       else if (!strcmp(cmd, "merge"))
+               msg = advice_commit_before_merge
+                     ? _("The following untracked working tree files would be overwritten by merge:\n%%s"
+                         "Please move or remove them before you merge.")
+                     : _("The following untracked working tree files would be overwritten by merge:\n%%s");
+       else
+               msg = advice_commit_before_merge
+                     ? _("The following untracked working tree files would be overwritten by %s:\n%%s"
+                         "Please move or remove them before you %s.")
+                     : _("The following untracked working tree files would be overwritten by %s:\n%%s");
+       msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = xstrfmt(msg, cmd, cmd);
 
        /*
         * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
         * cannot easily display it as a list.
         */
-       msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'.  Cannot bind.";
+       msgs[ERROR_BIND_OVERLAP] = _("Entry '%s' overlaps with '%s'.  Cannot bind.");
 
        msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
-               "Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
+               _("Cannot update sparse checkout: the following entries are not up-to-date:\n%s");
        msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
-               "The following Working tree files would be overwritten by sparse checkout update:\n%s";
+               _("The following working tree files would be overwritten by sparse checkout update:\n%s");
        msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
-               "The following Working tree files would be removed by sparse checkout update:\n%s";
+               _("The following working tree files would be removed by sparse checkout update:\n%s");
+       msgs[ERROR_WOULD_LOSE_SUBMODULE] =
+               _("Cannot update submodule:\n%s");
 
        opts->show_all_errors = 1;
        /* rejected paths may not have a static buffer */
@@ -138,7 +214,7 @@ static int add_rejected_path(struct unpack_trees_options *o,
                             const char *path)
 {
        if (!o->show_all_errors)
-               return error(ERRORMSG(o, e), path);
+               return error(ERRORMSG(o, e), super_prefixed(path));
 
        /*
         * Otherwise, insert in a list for future display by
@@ -162,13 +238,61 @@ static void display_error_msgs(struct unpack_trees_options *o)
                        something_displayed = 1;
                        for (i = 0; i < rejects->nr; i++)
                                strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
-                       error(ERRORMSG(o, e), path.buf);
+                       error(ERRORMSG(o, e), super_prefixed(path.buf));
                        strbuf_release(&path);
                }
                string_list_clear(rejects, 0);
        }
        if (something_displayed)
-               fprintf(stderr, "Aborting\n");
+               fprintf(stderr, _("Aborting\n"));
+}
+
+static int check_submodule_move_head(const struct cache_entry *ce,
+                                    const char *old_id,
+                                    const char *new_id,
+                                    struct unpack_trees_options *o)
+{
+       const struct submodule *sub = submodule_from_ce(ce);
+       if (!sub)
+               return 0;
+
+       switch (sub->update_strategy.type) {
+       case SM_UPDATE_UNSPECIFIED:
+       case SM_UPDATE_CHECKOUT:
+               if (submodule_move_head(ce->name, old_id, new_id, SUBMODULE_MOVE_HEAD_DRY_RUN))
+                       return o->gently ? -1 :
+                               add_rejected_path(o, ERROR_WOULD_LOSE_SUBMODULE, ce->name);
+               return 0;
+       case SM_UPDATE_NONE:
+               return 0;
+       case SM_UPDATE_REBASE:
+       case SM_UPDATE_MERGE:
+       case SM_UPDATE_COMMAND:
+       default:
+               warning(_("submodule update strategy not supported for submodule '%s'"), ce->name);
+               return -1;
+       }
+}
+
+static void reload_gitmodules_file(struct index_state *index,
+                                  struct checkout *state)
+{
+       int i;
+       for (i = 0; i < index->cache_nr; i++) {
+               struct cache_entry *ce = index->cache[i];
+               if (ce->ce_flags & CE_UPDATE) {
+                       int r = strcmp(ce->name, ".gitmodules");
+                       if (r < 0)
+                               continue;
+                       else if (r == 0) {
+                               submodule_free();
+                               checkout_entry(ce, state, NULL);
+                               gitmodules_config();
+                               git_config(submodule_config, NULL);
+                       } else
+                               break;
+               }
+       }
 }
 
 /*
@@ -177,6 +301,21 @@ static void display_error_msgs(struct unpack_trees_options *o)
  */
 static void unlink_entry(const struct cache_entry *ce)
 {
+       const struct submodule *sub = submodule_from_ce(ce);
+       if (sub) {
+               switch (sub->update_strategy.type) {
+               case SM_UPDATE_UNSPECIFIED:
+               case SM_UPDATE_CHECKOUT:
+               case SM_UPDATE_REBASE:
+               case SM_UPDATE_MERGE:
+                       submodule_move_head(ce->name, "HEAD", NULL,
+                                           SUBMODULE_MOVE_HEAD_FORCE);
+                       break;
+               case SM_UPDATE_NONE:
+               case SM_UPDATE_COMMAND:
+                       return; /* Do not touch the submodule. */
+               }
+       }
        if (!check_leading_path(ce->name, ce_namelen(ce)))
                return;
        if (remove_or_warn(ce->ce_mode, ce->name))
@@ -184,29 +323,42 @@ static void unlink_entry(const struct cache_entry *ce)
        schedule_dir_for_removal(ce->name, ce_namelen(ce));
 }
 
-static struct checkout state;
-static int check_updates(struct unpack_trees_options *o)
+static struct progress *get_progress(struct unpack_trees_options *o)
 {
        unsigned cnt = 0, total = 0;
+       struct index_state *index = &o->result;
+
+       if (!o->update || !o->verbose_update)
+               return NULL;
+
+       for (; cnt < index->cache_nr; cnt++) {
+               const struct cache_entry *ce = index->cache[cnt];
+               if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
+                       total++;
+       }
+
+       return start_progress_delay(_("Checking out files"),
+                                   total, 50, 1);
+}
+
+static int check_updates(struct unpack_trees_options *o)
+{
+       unsigned cnt = 0;
+       int errs = 0;
        struct progress *progress = NULL;
        struct index_state *index = &o->result;
+       struct checkout state = CHECKOUT_INIT;
        int i;
-       int errs = 0;
 
-       if (o->update && o->verbose_update) {
-               for (total = cnt = 0; cnt < index->cache_nr; cnt++) {
-                       const struct cache_entry *ce = index->cache[cnt];
-                       if (ce->ce_flags & (CE_UPDATE | CE_WT_REMOVE))
-                               total++;
-               }
+       state.force = 1;
+       state.quiet = 1;
+       state.refresh_cache = 1;
+       state.istate = index;
 
-               progress = start_progress_delay(_("Checking out files"),
-                                               total, 50, 1);
-               cnt = 0;
-       }
+       progress = get_progress(o);
 
        if (o->update)
-               git_attr_set_direction(GIT_ATTR_CHECKOUT, &o->result);
+               git_attr_set_direction(GIT_ATTR_CHECKOUT, index);
        for (i = 0; i < index->cache_nr; i++) {
                const struct cache_entry *ce = index->cache[i];
 
@@ -214,12 +366,14 @@ static int check_updates(struct unpack_trees_options *o)
                        display_progress(progress, ++cnt);
                        if (o->update && !o->dry_run)
                                unlink_entry(ce);
-                       continue;
                }
        }
-       remove_marked_cache_entries(&o->result);
+       remove_marked_cache_entries(index);
        remove_scheduled_dirs();
 
+       if (should_update_submodules() && o->update && !o->dry_run)
+               reload_gitmodules_file(index, &state);
+
        for (i = 0; i < index->cache_nr; i++) {
                struct cache_entry *ce = index->cache[i];
 
@@ -450,12 +604,18 @@ static int switch_cache_bottom(struct traverse_info *info)
        return ret;
 }
 
+static inline int are_same_oid(struct name_entry *name_j, struct name_entry *name_k)
+{
+       return name_j->oid && name_k->oid && !oidcmp(name_j->oid, name_k->oid);
+}
+
 static int traverse_trees_recursive(int n, unsigned long dirmask,
                                    unsigned long df_conflicts,
                                    struct name_entry *names,
                                    struct traverse_info *info)
 {
        int i, ret, bottom;
+       int nr_buf = 0;
        struct tree_desc t[MAX_UNPACK_TREES];
        void *buf[MAX_UNPACK_TREES];
        struct traverse_info newinfo;
@@ -472,18 +632,40 @@ static int traverse_trees_recursive(int n, unsigned long dirmask,
        newinfo.pathlen += tree_entry_len(p) + 1;
        newinfo.df_conflicts |= df_conflicts;
 
+       /*
+        * Fetch the tree from the ODB for each peer directory in the
+        * n commits.
+        *
+        * For 2- and 3-way traversals, we try to avoid hitting the
+        * ODB twice for the same OID.  This should yield a nice speed
+        * up in checkouts and merges when the commits are similar.
+        *
+        * We don't bother doing the full O(n^2) search for larger n,
+        * because wider traversals don't happen that often and we
+        * avoid the search setup.
+        *
+        * When 2 peer OIDs are the same, we just copy the tree
+        * descriptor data.  This implicitly borrows the buffer
+        * data from the earlier cell.
+        */
        for (i = 0; i < n; i++, dirmask >>= 1) {
-               const unsigned char *sha1 = NULL;
-               if (dirmask & 1)
-                       sha1 = names[i].sha1;
-               buf[i] = fill_tree_descriptor(t+i, sha1);
+               if (i > 0 && are_same_oid(&names[i], &names[i - 1]))
+                       t[i] = t[i - 1];
+               else if (i > 1 && are_same_oid(&names[i], &names[i - 2]))
+                       t[i] = t[i - 2];
+               else {
+                       const unsigned char *sha1 = NULL;
+                       if (dirmask & 1)
+                               sha1 = names[i].oid->hash;
+                       buf[nr_buf++] = fill_tree_descriptor(t+i, sha1);
+               }
        }
 
        bottom = switch_cache_bottom(&newinfo);
        ret = traverse_trees(n, t, &newinfo);
        restore_cache_bottom(&newinfo, bottom);
 
-       for (i = 0; i < n; i++)
+       for (i = 0; i < nr_buf; i++)
                free(buf[i]);
 
        return ret;
@@ -498,13 +680,14 @@ static int traverse_trees_recursive(int n, unsigned long dirmask,
  * 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)
+static int do_compare_entry_piecewise(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);
+               int cmp = do_compare_entry_piecewise(ce, info->prev,
+                                                    &info->name);
                if (cmp)
                        return cmp;
        }
@@ -522,6 +705,39 @@ static int do_compare_entry(const struct cache_entry *ce, const struct traverse_
        return df_name_compare(ce_name, ce_len, S_IFREG, n->path, len, n->mode);
 }
 
+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;
+       int cmp;
+
+       /*
+        * If we have not precomputed the traverse path, it is quicker
+        * to avoid doing so.  But if we have precomputed it,
+        * it is quicker to use the precomputed version.
+        */
+       if (!info->traverse_path)
+               return do_compare_entry_piecewise(ce, info, n);
+
+       cmp = strncmp(ce->name, info->traverse_path, info->pathlen);
+       if (cmp)
+               return cmp;
+
+       pathlen = info->pathlen;
+       ce_len = ce_namelen(ce);
+
+       if (ce_len < pathlen)
+               return -1;
+
+       ce_len -= pathlen;
+       ce_name = ce->name + pathlen;
+
+       len = tree_entry_len(n);
+       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);
@@ -557,7 +773,7 @@ static struct cache_entry *create_ce_entry(const struct traverse_info *info, con
        ce->ce_mode = create_ce_mode(n->mode);
        ce->ce_flags = create_ce_flags(stage);
        ce->ce_namelen = len;
-       hashcpy(ce->sha1, n->sha1);
+       oidcpy(&ce->oid, n->oid);
        make_traverse_path(ce->name, info, n);
 
        return ce;
@@ -661,8 +877,19 @@ static int find_cache_pos(struct traverse_info *info,
                                ++o->cache_bottom;
                        continue;
                }
-               if (!ce_in_traverse_path(ce, info))
+               if (!ce_in_traverse_path(ce, info)) {
+                       /*
+                        * Check if we can skip future cache checks
+                        * (because we're already past all possible
+                        * entries in the traverse path).
+                        */
+                       if (info->traverse_path) {
+                               if (strncmp(ce->name, info->traverse_path,
+                                           info->pathlen) > 0)
+                                       break;
+                       }
                        continue;
+               }
                ce_name = ce->name + pfxlen;
                ce_slash = strchr(ce_name, '/');
                if (ce_slash)
@@ -1018,21 +1245,17 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
        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;
-       state.istate = &o->result;
 
        memset(&el, 0, sizeof(el));
        if (!core_apply_sparse_checkout || !o->update)
                o->skip_sparse_checkout = 1;
        if (!o->skip_sparse_checkout) {
-               if (add_excludes_from_file_to_list(git_path("info/sparse-checkout"), "", 0, &el, 0) < 0)
+               char *sparse = git_pathdup("info/sparse-checkout");
+               if (add_excludes_from_file_to_list(sparse, "", 0, &el, 0) < 0)
                        o->skip_sparse_checkout = 1;
                else
                        o->el = &el;
+               free(sparse);
        }
 
        memset(&o->result, 0, sizeof(o->result));
@@ -1160,6 +1383,14 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
        o->src_index = NULL;
        ret = check_updates(o) ? (-2) : 0;
        if (o->dst_index) {
+               if (!ret) {
+                       if (!o->result.cache_tree)
+                               o->result.cache_tree = cache_tree();
+                       if (!cache_tree_fully_valid(o->result.cache_tree))
+                               cache_tree_update(&o->result,
+                                                 WRITE_TREE_SILENT |
+                                                 WRITE_TREE_REPAIR);
+               }
                discard_index(o->dst_index);
                *o->dst_index = o->result;
        } else {
@@ -1198,7 +1429,7 @@ static int same(const struct cache_entry *a, const struct cache_entry *b)
        if ((a->ce_flags | b->ce_flags) & CE_CONFLICTED)
                return 0;
        return a->ce_mode == b->ce_mode &&
-              !hashcmp(a->sha1, b->sha1);
+              !oidcmp(&a->oid, &b->oid);
 }
 
 
@@ -1228,17 +1459,26 @@ static int verify_uptodate_1(const struct cache_entry *ce,
        if (!lstat(ce->name, &st)) {
                int flags = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE;
                unsigned changed = ie_match_stat(o->src_index, ce, &st, flags);
+
+               if (submodule_from_ce(ce)) {
+                       int r = check_submodule_move_head(ce,
+                               "HEAD", oid_to_hex(&ce->oid), o);
+                       if (r)
+                               return o->gently ? -1 :
+                                       add_rejected_path(o, error_type, ce->name);
+                       return 0;
+               }
+
                if (!changed)
                        return 0;
                /*
-                * NEEDSWORK: the current default policy is to allow
-                * submodule to be out of sync wrt the superproject
-                * index.  This needs to be tightened later for
-                * submodules that are marked to be automatically
-                * checked out.
+                * Historic default policy was to allow submodule to be out
+                * of sync wrt the superproject index. If the submodule was
+                * not considered interesting above, we don't care here.
                 */
                if (S_ISGITLINK(ce->ce_mode))
                        return 0;
+
                errno = 0;
        }
        if (errno == ENOENT)
@@ -1277,11 +1517,16 @@ static void invalidate_ce_path(const struct cache_entry *ce,
  * Currently, git does not checkout subprojects during a superproject
  * checkout, so it is not going to overwrite anything.
  */
-static int verify_clean_submodule(const struct cache_entry *ce,
+static int verify_clean_submodule(const char *old_sha1,
+                                 const struct cache_entry *ce,
                                  enum unpack_trees_error_types error_type,
                                  struct unpack_trees_options *o)
 {
-       return 0;
+       if (!submodule_from_ce(ce))
+               return 0;
+
+       return check_submodule_move_head(ce, old_sha1,
+                                        oid_to_hex(&ce->oid), o);
 }
 
 static int verify_clean_subdirectory(const struct cache_entry *ce,
@@ -1297,16 +1542,18 @@ static int verify_clean_subdirectory(const struct cache_entry *ce,
        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
+       if (S_ISGITLINK(ce->ce_mode)) {
+               unsigned char sha1[20];
+               int sub_head = resolve_gitlink_ref(ce->name, "HEAD", sha1);
+               /*
+                * If we are not going to update the submodule, then
                 * we don't care.
                 */
-               if (!hashcmp(sha1, ce->sha1))
+               if (!sub_head && !hashcmp(sha1, ce->oid.hash))
                        return 0;
-               return verify_clean_submodule(ce, error_type, o);
+               return verify_clean_submodule(sub_head ? NULL : sha1_to_hex(sha1),
+                                             ce, error_type, o);
        }
 
        /*
@@ -1340,9 +1587,7 @@ static int verify_clean_subdirectory(const struct cache_entry *ce,
         * 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, "/");
+       pathbuf = xstrfmt("%.*s/", namelen, ce->name);
 
        memset(&d, 0, sizeof(d));
        if (o->dir)
@@ -1446,19 +1691,27 @@ static int verify_absent_1(const struct cache_entry *ce,
 
                path = xmemdupz(ce->name, len);
                if (lstat(path, &st))
-                       ret = error("cannot stat '%s': %s", path,
-                                       strerror(errno));
-               else
-                       ret = check_ok_to_remove(path, len, DT_UNKNOWN, NULL,
-                                                &st, error_type, o);
+                       ret = error_errno("cannot stat '%s'", path);
+               else {
+                       if (submodule_from_ce(ce))
+                               ret = check_submodule_move_head(ce,
+                                                               oid_to_hex(&ce->oid),
+                                                               NULL, o);
+                       else
+                               ret = check_ok_to_remove(path, len, DT_UNKNOWN, NULL,
+                                                        &st, error_type, o);
+               }
                free(path);
                return ret;
        } else if (lstat(ce->name, &st)) {
                if (errno != ENOENT)
-                       return error("cannot stat '%s': %s", ce->name,
-                                    strerror(errno));
+                       return error_errno("cannot stat '%s'", ce->name);
                return 0;
        } else {
+               if (submodule_from_ce(ce))
+                       return check_submodule_move_head(ce, oid_to_hex(&ce->oid),
+                                                        NULL, o);
+
                return check_ok_to_remove(ce->name, ce_namelen(ce),
                                          ce_to_dtype(ce), ce, &st,
                                          error_type, o);
@@ -1514,6 +1767,15 @@ static int merged_entry(const struct cache_entry *ce,
                        return -1;
                }
                invalidate_ce_path(merge, o);
+
+               if (submodule_from_ce(ce)) {
+                       int ret = check_submodule_move_head(ce, NULL,
+                                                           oid_to_hex(&ce->oid),
+                                                           o);
+                       if (ret)
+                               return ret;
+               }
+
        } else if (!(old->ce_flags & CE_CONFLICTED)) {
                /*
                 * See if we can re-use the old CE directly?
@@ -1534,6 +1796,14 @@ static int merged_entry(const struct cache_entry *ce,
                        update |= old->ce_flags & (CE_SKIP_WORKTREE | CE_NEW_SKIP_WORKTREE);
                        invalidate_ce_path(old, o);
                }
+
+               if (submodule_from_ce(ce)) {
+                       int ret = check_submodule_move_head(ce, oid_to_hex(&old->oid),
+                                                           oid_to_hex(&ce->oid),
+                                                           o);
+                       if (ret)
+                               return ret;
+               }
        } else {
                /*
                 * Previously unmerged entry left as an existence
@@ -1580,7 +1850,7 @@ static void show_stage_entry(FILE *o,
                fprintf(o, "%s%06o %s %d\t%s\n",
                        label,
                        ce->ce_mode,
-                       sha1_to_hex(ce->sha1),
+                       oid_to_hex(&ce->oid),
                        ce_stage(ce),
                        ce->name);
 }
@@ -1834,7 +2104,9 @@ int bind_merge(const struct cache_entry * const *src,
                             o->merge_size);
        if (a && old)
                return o->gently ? -1 :
-                       error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
+                       error(ERRORMSG(o, ERROR_BIND_OVERLAP),
+                             super_prefixed(a->name),
+                             super_prefixed(old->name));
        if (!a)
                return keep_entry(old, o);
        else