unpack_trees(): skip trees that are the same in all input
[gitweb.git] / unpack-trees.c
index 803445aa7be140c3707bcebc72aaf6fc6af45e4b..e1b4e996aed862da872c5e8d5a318d2b5d73127d 100644 (file)
@@ -53,6 +53,7 @@ const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                                  const char *cmd)
 {
+       int i;
        const char **msgs = opts->msgs;
        const char *msg;
        char *tmp;
@@ -96,6 +97,9 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                "The following Working tree files would be removed by sparse checkout update:\n%s";
 
        opts->show_all_errors = 1;
+       /* rejected paths may not have a static buffer */
+       for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
+               opts->unpack_rejects[i].strdup_strings = 1;
 }
 
 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
@@ -124,7 +128,6 @@ static int add_rejected_path(struct unpack_trees_options *o,
                             enum unpack_trees_error_types e,
                             const char *path)
 {
-       struct rejected_paths_list *newentry;
        if (!o->show_all_errors)
                return error(ERRORMSG(o, e), path);
 
@@ -132,45 +135,28 @@ static int add_rejected_path(struct unpack_trees_options *o,
         * Otherwise, insert in a list for future display by
         * display_error_msgs()
         */
-       newentry = xmalloc(sizeof(struct rejected_paths_list));
-       newentry->path = (char *)path;
-       newentry->next = o->unpack_rejects[e];
-       o->unpack_rejects[e] = newentry;
+       string_list_append(&o->unpack_rejects[e], path);
        return -1;
 }
 
-/*
- * free all the structures allocated for the error <e>
- */
-static void free_rejected_paths(struct unpack_trees_options *o,
-                               enum unpack_trees_error_types e)
-{
-       while (o->unpack_rejects[e]) {
-               struct rejected_paths_list *del = o->unpack_rejects[e];
-               o->unpack_rejects[e] = o->unpack_rejects[e]->next;
-               free(del);
-       }
-       free(o->unpack_rejects[e]);
-}
-
 /*
  * display all the error messages stored in a nice way
  */
 static void display_error_msgs(struct unpack_trees_options *o)
 {
-       int e;
+       int e, i;
        int something_displayed = 0;
        for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
-               if (o->unpack_rejects[e]) {
-                       struct rejected_paths_list *rp;
+               struct string_list *rejects = &o->unpack_rejects[e];
+               if (rejects->nr > 0) {
                        struct strbuf path = STRBUF_INIT;
                        something_displayed = 1;
-                       for (rp = o->unpack_rejects[e]; rp; rp = rp->next)
-                               strbuf_addf(&path, "\t%s\n", rp->path);
+                       for (i = 0; i < rejects->nr; i++)
+                               strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
                        error(ERRORMSG(o, e), path.buf);
                        strbuf_release(&path);
-                       free_rejected_paths(o, e);
                }
+               string_list_clear(rejects, 0);
        }
        if (something_displayed)
                printf("Aborting\n");
@@ -182,7 +168,7 @@ static void display_error_msgs(struct unpack_trees_options *o)
  */
 static void unlink_entry(struct cache_entry *ce)
 {
-       if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
+       if (!check_leading_path(ce->name, ce_namelen(ce)))
                return;
        if (remove_or_warn(ce->ce_mode, ce->name))
                return;
@@ -404,7 +390,7 @@ static void add_same_unmerged(struct cache_entry *ce,
 static int unpack_index_entry(struct cache_entry *ce,
                              struct unpack_trees_options *o)
 {
-       struct cache_entry *src[5] = { NULL };
+       struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
        int ret;
 
        src[0] = ce;
@@ -450,7 +436,14 @@ static int switch_cache_bottom(struct traverse_info *info)
        return ret;
 }
 
-static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long df_conflicts, struct name_entry *names, struct traverse_info *info)
+static int fast_forward_merge(int n, unsigned long dirmask,
+                             struct name_entry *names,
+                             struct traverse_info *info);
+
+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;
        struct tree_desc t[MAX_UNPACK_TREES];
@@ -458,6 +451,11 @@ static int traverse_trees_recursive(int n, unsigned long dirmask, unsigned long
        struct traverse_info newinfo;
        struct name_entry *p;
 
+       if (!df_conflicts) {
+               int status = fast_forward_merge(n, dirmask, names, info);
+               if (status)
+                       return status;
+       }
        p = names;
        while (!p->mode)
                p++;
@@ -705,6 +703,53 @@ static struct cache_entry *find_cache_entry(struct traverse_info *info,
                return NULL;
 }
 
+static int fast_forward_merge(int n, unsigned long dirmask,
+                             struct name_entry *names,
+                             struct traverse_info *info)
+{
+       int i;
+       struct cache_entry *src[MAX_UNPACK_TREES + 1] = { NULL, };
+       struct unpack_trees_options *o = info->data;
+
+       /* merging two or more trees with an identical subdirectory? */
+       if ((n < 2) || ((1UL << n) - 1) != dirmask ||
+           !o->merge || o->reset || o->initial_checkout)
+               return 0;
+       for (i = 1; i < n; i++)
+               if (hashcmp(names[i-1].sha1, names[i].sha1))
+                       return 0;
+
+       /*
+        * Instead of descending into the directory, keep the contents
+        * of the current index.
+        */
+       while (1) {
+               struct cache_entry *ce;
+               ce = next_cache_entry(o);
+               if (!ce)
+                       break;
+               /* Is the entry still in that directory? */
+               if (do_compare_entry(ce, info, names))
+                       break;
+               /*
+                * Note: we do not just run unpack_index_entry() here,
+                * as the callback may want to compare what is in the
+                * index with what are from the HEAD and the other tree
+                * and reject the merge.  We pretend that ancestors, the
+                * HEAD and the other tree all have the same contents as
+                * the current index, which is a lie, but it works.
+                */
+               for (i = 0; i < n + 1; i++)
+                       src[i] = ce;
+               mark_ce_used(ce, o);
+               if (call_unpack_fn(src, o) < 0)
+                       return unpack_failed(o, NULL);
+               if (ce_stage(ce))
+                       mark_ce_used_same_name(ce, o);
+       }
+       return dirmask;
+}
+
 static void debug_path(struct traverse_info *info)
 {
        if (info->prev) {
@@ -922,7 +967,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
        if (!o->skip_sparse_checkout) {
                int empty_worktree = 1;
-               for (i = 0;i < o->result.cache_nr;i++) {
+               for (i = 0; i < o->result.cache_nr; i++) {
                        struct cache_entry *ce = o->result.cache[i];
 
                        if (apply_sparse_checkout(ce, o)) {
@@ -934,6 +979,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 
                }
                if (o->result.cache_nr && empty_worktree) {
+                       /* dubious---why should this fail??? */
                        ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
                        goto done;
                }
@@ -945,7 +991,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
                *o->dst_index = o->result;
 
 done:
-       for (i = 0;i < el.nr;i++)
+       for (i = 0; i < el.nr; i++)
                free(el.excludes[i]);
        if (el.excludes)
                free(el.excludes);
@@ -1127,14 +1173,65 @@ static int verify_clean_subdirectory(struct cache_entry *ce,
  * See if we can find a case-insensitive match in the index that also
  * matches the stat information, and assume it's that other file!
  */
-static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst, struct stat *st)
+static int icase_exists(struct unpack_trees_options *o, const char *name, int len, struct stat *st)
 {
        struct cache_entry *src;
 
-       src = index_name_exists(o->src_index, dst->name, ce_namelen(dst), 1);
+       src = index_name_exists(o->src_index, name, len, 1);
        return src && !ie_match_stat(o->src_index, src, st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);
 }
 
+static int check_ok_to_remove(const char *name, int len, int dtype,
+                             struct cache_entry *ce, struct stat *st,
+                             enum unpack_trees_error_types error_type,
+                             struct unpack_trees_options *o)
+{
+       struct cache_entry *result;
+
+       /*
+        * It may be that the 'lstat()' succeeded even though
+        * target 'ce' was absent, because there is an old
+        * entry that is different only in case..
+        *
+        * Ignore that lstat() if it matches.
+        */
+       if (ignore_case && icase_exists(o, name, len, st))
+               return 0;
+
+       if (o->dir && excluded(o->dir, name, &dtype))
+               /*
+                * ce->name is explicitly excluded, so it is Ok to
+                * overwrite it.
+                */
+               return 0;
+       if (S_ISDIR(st->st_mode)) {
+               /*
+                * We are checking out path "foo" and
+                * found "foo/." in the working tree.
+                * This is tricky -- if we have modified
+                * files that are in "foo/" we would lose
+                * them.
+                */
+               if (verify_clean_subdirectory(ce, error_type, o) < 0)
+                       return -1;
+               return 0;
+       }
+
+       /*
+        * The previous round may already have decided to
+        * delete this path, which is in a subdirectory that
+        * is being replaced with a blob.
+        */
+       result = index_name_exists(&o->result, name, len, 0);
+       if (result) {
+               if (result->ce_flags & CE_REMOVE)
+                       return 0;
+       }
+
+       return o->gently ? -1 :
+               add_rejected_path(o, error_type, name);
+}
+
 /*
  * We do not want to remove or overwrite a working tree file that
  * is not tracked, unless it is ignored.
@@ -1143,63 +1240,31 @@ static int verify_absent_1(struct cache_entry *ce,
                                 enum unpack_trees_error_types error_type,
                                 struct unpack_trees_options *o)
 {
+       int len;
        struct stat st;
 
        if (o->index_only || o->reset || !o->update)
                return 0;
 
-       if (has_symlink_or_noent_leading_path(ce->name, ce_namelen(ce)))
+       len = check_leading_path(ce->name, ce_namelen(ce));
+       if (!len)
                return 0;
+       else if (len > 0) {
+               char path[PATH_MAX + 1];
+               memcpy(path, ce->name, len);
+               path[len] = 0;
+               lstat(path, &st);
+
+               return check_ok_to_remove(path, len, DT_UNKNOWN, NULL, &st,
+                               error_type, o);
+       } else if (!lstat(ce->name, &st))
+               return check_ok_to_remove(ce->name, ce_namelen(ce),
+                               ce_to_dtype(ce), ce, &st,
+                               error_type, o);
 
-       if (!lstat(ce->name, &st)) {
-               int dtype = ce_to_dtype(ce);
-               struct cache_entry *result;
-
-               /*
-                * It may be that the 'lstat()' succeeded even though
-                * target 'ce' was absent, because there is an old
-                * entry that is different only in case..
-                *
-                * Ignore that lstat() if it matches.
-                */
-               if (ignore_case && icase_exists(o, ce, &st))
-                       return 0;
-
-               if (o->dir && excluded(o->dir, ce->name, &dtype))
-                       /*
-                        * ce->name is explicitly excluded, so it is Ok to
-                        * overwrite it.
-                        */
-                       return 0;
-               if (S_ISDIR(st.st_mode)) {
-                       /*
-                        * We are checking out path "foo" and
-                        * found "foo/." in the working tree.
-                        * This is tricky -- if we have modified
-                        * files that are in "foo/" we would lose
-                        * them.
-                        */
-                       if (verify_clean_subdirectory(ce, error_type, o) < 0)
-                               return -1;
-                       return 0;
-               }
-
-               /*
-                * The previous round may already have decided to
-                * delete this path, which is in a subdirectory that
-                * is being replaced with a blob.
-                */
-               result = index_name_exists(&o->result, ce->name, ce_namelen(ce), 0);
-               if (result) {
-                       if (result->ce_flags & CE_REMOVE)
-                               return 0;
-               }
-
-               return o->gently ? -1 :
-                       add_rejected_path(o, error_type, ce->name);
-       }
        return 0;
 }
+
 static int verify_absent(struct cache_entry *ce,
                         enum unpack_trees_error_types error_type,
                         struct unpack_trees_options *o)