+ /*
+ * Trivial optimization: if we find an entry that
+ * already matches the sub-directory, then we know
+ * we're ok, and we can exit.
+ */
+ pos = -pos-1;
+ while (pos < active_nr) {
+ struct cache_entry *p = active_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 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(const struct cache_entry *ce, int pos, int ok_to_replace)
+{
+ /*
+ * 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
+ */
+ int retval = has_file_name(ce, pos, ok_to_replace);
+ /*
+ * Then check if the path might have a clashing sub-directory
+ * before it.
+ */
+ return retval + has_dir_name(ce, pos, ok_to_replace);
+}
+
+int add_cache_entry(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;
+ pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
+
+ /* existing match? Just replace it. */