filter-branch: add git_commit_non_empty_tree and --prune-empty.
[gitweb.git] / builtin-read-tree.c
index 6bc042f852cb56739810d1f66e4295d805b5aeca..38fef34d3fb6c24ab89043951f1ecf6c96e9bf51 100644 (file)
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#define DBRT_DEBUG 1
 
 #include "cache.h"
-
 #include "object.h"
 #include "tree.h"
 #include "tree-walk.h"
 #include "cache-tree.h"
 #include "unpack-trees.h"
+#include "dir.h"
 #include "builtin.h"
 
-static struct object_list *trees = NULL;
-
-static void reject_merge(struct cache_entry *ce)
-{
-       die("Entry '%s' would be overwritten by merge. Cannot merge.",
-           ce->name);
-}
+static int nr_trees;
+static struct tree *trees[MAX_UNPACK_TREES];
 
 static int list_tree(unsigned char *sha1)
 {
-       struct tree *tree = parse_tree_indirect(sha1);
+       struct tree *tree;
+
+       if (nr_trees >= MAX_UNPACK_TREES)
+               die("I cannot read more than %d trees", MAX_UNPACK_TREES);
+       tree = parse_tree_indirect(sha1);
        if (!tree)
                return -1;
-       object_list_append(&tree->object, &trees);
+       trees[nr_trees++] = tree;
        return 0;
 }
 
-static int same(struct cache_entry *a, struct cache_entry *b)
-{
-       if (!!a != !!b)
-               return 0;
-       if (!a && !b)
-               return 1;
-       return a->ce_mode == b->ce_mode && 
-               !memcmp(a->sha1, b->sha1, 20);
-}
-
-
-/*
- * When a CE gets turned into an unmerged entry, we
- * want it to be up-to-date
- */
-static void verify_uptodate(struct cache_entry *ce,
-               struct unpack_trees_options *o)
-{
-       struct stat st;
-
-       if (o->index_only || o->reset)
-               return;
-
-       if (!lstat(ce->name, &st)) {
-               unsigned changed = ce_match_stat(ce, &st, 1);
-               if (!changed)
-                       return;
-               errno = 0;
-       }
-       if (o->reset) {
-               ce->ce_flags |= htons(CE_UPDATE);
-               return;
-       }
-       if (errno == ENOENT)
-               return;
-       die("Entry '%s' not uptodate. Cannot merge.", ce->name);
-}
-
-static void invalidate_ce_path(struct cache_entry *ce)
-{
-       if (ce)
-               cache_tree_invalidate_path(active_cache_tree, ce->name);
-}
-
-/*
- * We do not want to remove or overwrite a working tree file that
- * is not tracked.
- */
-static void verify_absent(const char *path, const char *action,
-               struct unpack_trees_options *o)
-{
-       struct stat st;
-
-       if (o->index_only || o->reset || !o->update)
-               return;
-       if (!lstat(path, &st))
-               die("Untracked working tree file '%s' "
-                   "would be %s by merge.", path, action);
-}
-
-static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
-               struct unpack_trees_options *o)
-{
-       merge->ce_flags |= htons(CE_UPDATE);
-       if (old) {
-               /*
-                * See if we can re-use the old CE directly?
-                * That way we get the uptodate stat info.
-                *
-                * This also removes the UPDATE flag on
-                * a match.
-                */
-               if (same(old, merge)) {
-                       *merge = *old;
-               } else {
-                       verify_uptodate(old, o);
-                       invalidate_ce_path(old);
-               }
-       }
-       else {
-               verify_absent(merge->name, "overwritten", o);
-               invalidate_ce_path(merge);
-       }
-
-       merge->ce_flags &= ~htons(CE_STAGEMASK);
-       add_cache_entry(merge, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
-       return 1;
-}
-
-static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
-               struct unpack_trees_options *o)
-{
-       if (old)
-               verify_uptodate(old, o);
-       else
-               verify_absent(ce->name, "removed", o);
-       ce->ce_mode = 0;
-       add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
-       invalidate_ce_path(ce);
-       return 1;
-}
-
-static int keep_entry(struct cache_entry *ce)
-{
-       add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
-       return 1;
-}
-
-#if DBRT_DEBUG
-static void show_stage_entry(FILE *o,
-                            const char *label, const struct cache_entry *ce)
-{
-       if (!ce)
-               fprintf(o, "%s (missing)\n", label);
-       else
-               fprintf(o, "%s%06o %s %d\t%s\n",
-                       label,
-                       ntohl(ce->ce_mode),
-                       sha1_to_hex(ce->sha1),
-                       ce_stage(ce),
-                       ce->name);
-}
-#endif
-
-static int threeway_merge(struct cache_entry **stages,
-               struct unpack_trees_options *o)
-{
-       struct cache_entry *index;
-       struct cache_entry *head;
-       struct cache_entry *remote = stages[o->head_idx + 1];
-       int count;
-       int head_match = 0;
-       int remote_match = 0;
-       const char *path = NULL;
-
-       int df_conflict_head = 0;
-       int df_conflict_remote = 0;
-
-       int any_anc_missing = 0;
-       int no_anc_exists = 1;
-       int i;
-
-       for (i = 1; i < o->head_idx; i++) {
-               if (!stages[i])
-                       any_anc_missing = 1;
-               else {
-                       if (!path)
-                               path = stages[i]->name;
-                       no_anc_exists = 0;
-               }
-       }
-
-       index = stages[0];
-       head = stages[o->head_idx];
-
-       if (head == &o->df_conflict_entry) {
-               df_conflict_head = 1;
-               head = NULL;
-       }
-
-       if (remote == &o->df_conflict_entry) {
-               df_conflict_remote = 1;
-               remote = NULL;
-       }
-
-       if (!path && index)
-               path = index->name;
-       if (!path && head)
-               path = head->name;
-       if (!path && remote)
-               path = remote->name;
-
-       /* First, if there's a #16 situation, note that to prevent #13
-        * and #14.
-        */
-       if (!same(remote, head)) {
-               for (i = 1; i < o->head_idx; i++) {
-                       if (same(stages[i], head)) {
-                               head_match = i;
-                       }
-                       if (same(stages[i], remote)) {
-                               remote_match = i;
-                       }
-               }
-       }
-
-       /* We start with cases where the index is allowed to match
-        * something other than the head: #14(ALT) and #2ALT, where it
-        * is permitted to match the result instead.
-        */
-       /* #14, #14ALT, #2ALT */
-       if (remote && !df_conflict_head && head_match && !remote_match) {
-               if (index && !same(index, remote) && !same(index, head))
-                       reject_merge(index);
-               return merged_entry(remote, index, o);
-       }
-       /*
-        * If we have an entry in the index cache, then we want to
-        * make sure that it matches head.
-        */
-       if (index && !same(index, head)) {
-               reject_merge(index);
-       }
-
-       if (head) {
-               /* #5ALT, #15 */
-               if (same(head, remote))
-                       return merged_entry(head, index, o);
-               /* #13, #3ALT */
-               if (!df_conflict_remote && remote_match && !head_match)
-                       return merged_entry(head, index, o);
-       }
-
-       /* #1 */
-       if (!head && !remote && any_anc_missing)
-               return 0;
-
-       /* Under the new "aggressive" rule, we resolve mostly trivial
-        * cases that we historically had git-merge-one-file resolve.
-        */
-       if (o->aggressive) {
-               int head_deleted = !head && !df_conflict_head;
-               int remote_deleted = !remote && !df_conflict_remote;
-               /*
-                * Deleted in both.
-                * Deleted in one and unchanged in the other.
-                */
-               if ((head_deleted && remote_deleted) ||
-                   (head_deleted && remote && remote_match) ||
-                   (remote_deleted && head && head_match)) {
-                       if (index)
-                               return deleted_entry(index, index, o);
-                       else if (path)
-                               verify_absent(path, "removed", o);
-                       return 0;
-               }
-               /*
-                * Added in both, identically.
-                */
-               if (no_anc_exists && head && remote && same(head, remote))
-                       return merged_entry(head, index, o);
-
-       }
-
-       /* Below are "no merge" cases, which require that the index be
-        * up-to-date to avoid the files getting overwritten with
-        * conflict resolution files.
-        */
-       if (index) {
-               verify_uptodate(index, o);
-       }
-       else if (path)
-               verify_absent(path, "overwritten", o);
-
-       o->nontrivial_merge = 1;
-
-       /* #2, #3, #4, #6, #7, #9, #11. */
-       count = 0;
-       if (!head_match || !remote_match) {
-               for (i = 1; i < o->head_idx; i++) {
-                       if (stages[i]) {
-                               keep_entry(stages[i]);
-                               count++;
-                               break;
-                       }
-               }
-       }
-#if DBRT_DEBUG
-       else {
-               fprintf(stderr, "read-tree: warning #16 detected\n");
-               show_stage_entry(stderr, "head   ", stages[head_match]);
-               show_stage_entry(stderr, "remote ", stages[remote_match]);
-       }
-#endif
-       if (head) { count += keep_entry(head); }
-       if (remote) { count += keep_entry(remote); }
-       return count;
-}
-
-/*
- * Two-way merge.
- *
- * The rule is to "carry forward" what is in the index without losing
- * information across a "fast forward", favoring a successful merge
- * over a merge failure when it makes sense.  For details of the
- * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
- *
- */
-static int twoway_merge(struct cache_entry **src,
-               struct unpack_trees_options *o)
-{
-       struct cache_entry *current = src[0];
-       struct cache_entry *oldtree = src[1], *newtree = src[2];
-
-       if (o->merge_size != 2)
-               return error("Cannot do a twoway merge of %d trees",
-                            o->merge_size);
-
-       if (current) {
-               if ((!oldtree && !newtree) || /* 4 and 5 */
-                   (!oldtree && newtree &&
-                    same(current, newtree)) || /* 6 and 7 */
-                   (oldtree && newtree &&
-                    same(oldtree, newtree)) || /* 14 and 15 */
-                   (oldtree && newtree &&
-                    !same(oldtree, newtree) && /* 18 and 19*/
-                    same(current, newtree))) {
-                       return keep_entry(current);
-               }
-               else if (oldtree && !newtree && same(current, oldtree)) {
-                       /* 10 or 11 */
-                       return deleted_entry(oldtree, current, o);
-               }
-               else if (oldtree && newtree &&
-                        same(current, oldtree) && !same(current, newtree)) {
-                       /* 20 or 21 */
-                       return merged_entry(newtree, current, o);
-               }
-               else {
-                       /* all other failures */
-                       if (oldtree)
-                               reject_merge(oldtree);
-                       if (current)
-                               reject_merge(current);
-                       if (newtree)
-                               reject_merge(newtree);
-                       return -1;
-               }
-       }
-       else if (newtree)
-               return merged_entry(newtree, current, o);
-       else
-               return deleted_entry(oldtree, current, o);
-}
-
-/*
- * Bind merge.
- *
- * Keep the index entries at stage0, collapse stage1 but make sure
- * stage0 does not have anything there.
- */
-static int bind_merge(struct cache_entry **src,
-               struct unpack_trees_options *o)
-{
-       struct cache_entry *old = src[0];
-       struct cache_entry *a = src[1];
-
-       if (o->merge_size != 1)
-               return error("Cannot do a bind merge of %d trees\n",
-                            o->merge_size);
-       if (a && old)
-               die("Entry '%s' overlaps.  Cannot bind.", a->name);
-       if (!a)
-               return keep_entry(old);
-       else
-               return merged_entry(a, NULL, o);
-}
-
-/*
- * One-way merge.
- *
- * The rule is:
- * - take the stat information from stage0, take the data from stage1
- */
-static int oneway_merge(struct cache_entry **src,
-               struct unpack_trees_options *o)
-{
-       struct cache_entry *old = src[0];
-       struct cache_entry *a = src[1];
-
-       if (o->merge_size != 1)
-               return error("Cannot do a oneway merge of %d trees",
-                            o->merge_size);
-
-       if (!a)
-               return deleted_entry(old, old, o);
-       if (old && same(old, a)) {
-               if (o->reset) {
-                       struct stat st;
-                       if (lstat(old->name, &st) ||
-                           ce_match_stat(old, &st, 1))
-                               old->ce_flags |= htons(CE_UPDATE);
-               }
-               return keep_entry(old);
-       }
-       return merged_entry(a, old, o);
-}
-
-static int read_cache_unmerged(void)
-{
-       int i;
-       struct cache_entry **dst;
-       struct cache_entry *last = NULL;
-
-       read_cache();
-       dst = active_cache;
-       for (i = 0; i < active_nr; i++) {
-               struct cache_entry *ce = active_cache[i];
-               if (ce_stage(ce)) {
-                       if (last && !strcmp(ce->name, last->name))
-                               continue;
-                       invalidate_ce_path(ce);
-                       last = ce;
-                       ce->ce_mode = 0;
-                       ce->ce_flags &= ~htons(CE_STAGEMASK);
-               }
-               *dst++ = ce;
-       }
-       active_nr = dst - active_cache;
-       return !!last;
-}
-
 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 {
        struct tree_desc desc;
        struct name_entry entry;
        int cnt;
 
-       memcpy(it->sha1, tree->object.sha1, 20);
-       desc.buf = tree->buffer;
-       desc.size = tree->size;
+       hashcpy(it->sha1, tree->object.sha1);
+       init_tree_desc(&desc, tree->buffer, tree->size);
        cnt = 0;
        while (tree_entry(&desc, &entry)) {
                if (!S_ISDIR(entry.mode))
@@ -472,35 +57,32 @@ static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 
 static void prime_cache_tree(void)
 {
-       struct tree *tree = (struct tree *)trees->item;
-       if (!tree)
+       if (!nr_trees)
                return;
        active_cache_tree = cache_tree();
-       prime_cache_tree_rec(active_cache_tree, tree);
+       prime_cache_tree_rec(active_cache_tree, trees[0]);
 
 }
 
-static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <sha1> [<sha2> [<sha3>]])";
+static const char read_tree_usage[] = "git read-tree (<sha> | [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] [--index-output=<file>] <sha1> [<sha2> [<sha3>]])";
 
 static struct lock_file lock_file;
 
-int cmd_read_tree(int argc, const char **argv, const char *prefix)
+int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 {
        int i, newfd, stage = 0;
        unsigned char sha1[20];
+       struct tree_desc t[MAX_UNPACK_TREES];
        struct unpack_trees_options opts;
 
        memset(&opts, 0, sizeof(opts));
        opts.head_idx = -1;
+       opts.src_index = &the_index;
+       opts.dst_index = &the_index;
 
-       setup_git_directory();
-       git_config(git_default_config);
+       git_config(git_default_config, NULL);
 
-       newfd = hold_lock_file_for_update(&lock_file, get_index_file());
-       if (newfd < 0)
-               die("unable to create new index file");
-
-       git_config(git_default_config);
+       newfd = hold_locked_index(&lock_file, 1);
 
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
@@ -526,11 +108,16 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                        continue;
                }
 
+               if (!prefixcmp(arg, "--index-output=")) {
+                       set_alternate_index_output(arg + 15);
+                       continue;
+               }
+
                /* "--prefix=<subdirectory>/" means keep the current index
                 *  entries and put the entries from the tree under the
                 * given subdirectory.
                 */
-               if (!strncmp(arg, "--prefix=", 9)) {
+               if (!prefixcmp(arg, "--prefix=")) {
                        if (stage || opts.merge || opts.prefix)
                                usage(read_tree_usage);
                        opts.prefix = arg + 9;
@@ -576,6 +163,23 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                        continue;
                }
 
+               if (!prefixcmp(arg, "--exclude-per-directory=")) {
+                       struct dir_struct *dir;
+
+                       if (opts.dir)
+                               die("more than one --exclude-per-directory are given.");
+
+                       dir = xcalloc(1, sizeof(*opts.dir));
+                       dir->show_ignored = 1;
+                       dir->exclude_per_dir = arg + 24;
+                       opts.dir = dir;
+                       /* We do not need to nor want to do read-directory
+                        * here; we are merely interested in reusing the
+                        * per directory ignore stack mechanism.
+                        */
+                       continue;
+               }
+
                /* using -u and -i at the same time makes no sense */
                if (1 < opts.index_only + opts.update)
                        usage(read_tree_usage);
@@ -588,26 +192,10 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
        }
        if ((opts.update||opts.index_only) && !opts.merge)
                usage(read_tree_usage);
-
-       if (opts.prefix) {
-               int pfxlen = strlen(opts.prefix);
-               int pos;
-               if (opts.prefix[pfxlen-1] != '/')
-                       die("prefix must end with /");
-               if (stage != 2)
-                       die("binding merge takes only one tree");
-               pos = cache_name_pos(opts.prefix, pfxlen);
-               if (0 <= pos)
-                       die("corrupt index file");
-               pos = -pos-1;
-               if (pos < active_nr &&
-                   !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
-                       die("subdirectory '%s' already exists.", opts.prefix);
-               pos = cache_name_pos(opts.prefix, pfxlen-1);
-               if (0 <= pos)
-                       die("file '%.*s' already exists.",
-                                       pfxlen-1, opts.prefix);
-       }
+       if ((opts.dir && !opts.update))
+               die("--exclude-per-directory is meaningless unless -u");
+       if (opts.merge && !opts.index_only)
+               setup_work_tree();
 
        if (opts.merge) {
                if (stage < 2)
@@ -618,6 +206,7 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                        break;
                case 2:
                        opts.fn = twoway_merge;
+                       opts.initial_checkout = is_cache_unborn();
                        break;
                case 3:
                default:
@@ -632,7 +221,13 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                        opts.head_idx = 1;
        }
 
-       unpack_trees(trees, &opts);
+       for (i = 0; i < nr_trees; i++) {
+               struct tree *tree = trees[i];
+               parse_tree(tree);
+               init_tree_desc(t+i, tree->buffer, tree->size);
+       }
+       if (unpack_trees(nr_trees, t, &opts))
+               return 128;
 
        /*
         * When reading only one tree (either the most basic form,
@@ -640,13 +235,13 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
         * valid cache-tree because the index must match exactly
         * what came from the tree.
         */
-       if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
+       if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
                cache_tree_free(&active_cache_tree);
                prime_cache_tree();
        }
 
        if (write_cache(newfd, active_cache, active_nr) ||
-           close(newfd) || commit_lock_file(&lock_file))
+           commit_locked_index(&lock_file))
                die("unable to write new index file");
        return 0;
 }