read-trees: refactor the unpack_trees() part
[git/git.git] / builtin-read-tree.c
index 49c10bf..6bc042f 100644 (file)
 #include "tree.h"
 #include "tree-walk.h"
 #include "cache-tree.h"
-#include <sys/time.h>
-#include <signal.h>
+#include "unpack-trees.h"
 #include "builtin.h"
 
-static int reset = 0;
-static int merge = 0;
-static int update = 0;
-static int index_only = 0;
-static int nontrivial_merge = 0;
-static int trivial_merges_only = 0;
-static int aggressive = 0;
-static int verbose_update = 0;
-static volatile int progress_update = 0;
-static const char *prefix = NULL;
-
-static int head_idx = -1;
-static int merge_size = 0;
-
 static struct object_list *trees = NULL;
 
-static struct cache_entry df_conflict_entry;
-
-struct tree_entry_list {
-       struct tree_entry_list *next;
-       unsigned directory : 1;
-       unsigned executable : 1;
-       unsigned symlink : 1;
-       unsigned int mode;
-       const char *name;
-       const unsigned char *sha1;
-};
-
-static struct tree_entry_list df_conflict_list;
-
-typedef int (*merge_fn_t)(struct cache_entry **src);
-
-static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
-{
-       struct tree_desc desc;
-       struct name_entry one;
-       struct tree_entry_list *ret = NULL;
-       struct tree_entry_list **list_p = &ret;
-
-       desc.buf = tree->buffer;
-       desc.size = tree->size;
-
-       while (tree_entry(&desc, &one)) {
-               struct tree_entry_list *entry;
-
-               entry = xmalloc(sizeof(struct tree_entry_list));
-               entry->name = one.path;
-               entry->sha1 = one.sha1;
-               entry->mode = one.mode;
-               entry->directory = S_ISDIR(one.mode) != 0;
-               entry->executable = (one.mode & S_IXUSR) != 0;
-               entry->symlink = S_ISLNK(one.mode) != 0;
-               entry->next = NULL;
-
-               *list_p = entry;
-               list_p = &entry->next;
-       }
-       return ret;
-}
-
-static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
-{
-       int len1 = strlen(name1);
-       int len2 = strlen(name2);
-       int len = len1 < len2 ? len1 : len2;
-       int ret = memcmp(name1, name2, len);
-       unsigned char c1, c2;
-       if (ret)
-               return ret;
-       c1 = name1[len];
-       c2 = name2[len];
-       if (!c1 && dir1)
-               c1 = '/';
-       if (!c2 && dir2)
-               c2 = '/';
-       ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
-       if (c1 && c2 && !ret)
-               ret = len1 - len2;
-       return ret;
-}
-
-static int unpack_trees_rec(struct tree_entry_list **posns, int len,
-                           const char *base, merge_fn_t fn, int *indpos)
-{
-       int baselen = strlen(base);
-       int src_size = len + 1;
-       do {
-               int i;
-               const char *first;
-               int firstdir = 0;
-               int pathlen;
-               unsigned ce_size;
-               struct tree_entry_list **subposns;
-               struct cache_entry **src;
-               int any_files = 0;
-               int any_dirs = 0;
-               char *cache_name;
-               int ce_stage;
-
-               /* Find the first name in the input. */
-
-               first = NULL;
-               cache_name = NULL;
-
-               /* Check the cache */
-               if (merge && *indpos < active_nr) {
-                       /* This is a bit tricky: */
-                       /* If the index has a subdirectory (with
-                        * contents) as the first name, it'll get a
-                        * filename like "foo/bar". But that's after
-                        * "foo", so the entry in trees will get
-                        * handled first, at which point we'll go into
-                        * "foo", and deal with "bar" from the index,
-                        * because the base will be "foo/". The only
-                        * way we can actually have "foo/bar" first of
-                        * all the things is if the trees don't
-                        * contain "foo" at all, in which case we'll
-                        * handle "foo/bar" without going into the
-                        * directory, but that's fine (and will return
-                        * an error anyway, with the added unknown
-                        * file case.
-                        */
-
-                       cache_name = active_cache[*indpos]->name;
-                       if (strlen(cache_name) > baselen &&
-                           !memcmp(cache_name, base, baselen)) {
-                               cache_name += baselen;
-                               first = cache_name;
-                       } else {
-                               cache_name = NULL;
-                       }
-               }
-
-#if DBRT_DEBUG > 1
-               if (first)
-                       printf("index %s\n", first);
-#endif
-               for (i = 0; i < len; i++) {
-                       if (!posns[i] || posns[i] == &df_conflict_list)
-                               continue;
-#if DBRT_DEBUG > 1
-                       printf("%d %s\n", i + 1, posns[i]->name);
-#endif
-                       if (!first || entcmp(first, firstdir,
-                                            posns[i]->name, 
-                                            posns[i]->directory) > 0) {
-                               first = posns[i]->name;
-                               firstdir = posns[i]->directory;
-                       }
-               }
-               /* No name means we're done */
-               if (!first)
-                       return 0;
-
-               pathlen = strlen(first);
-               ce_size = cache_entry_size(baselen + pathlen);
-
-               src = xcalloc(src_size, sizeof(struct cache_entry *));
-
-               subposns = xcalloc(len, sizeof(struct tree_list_entry *));
-
-               if (cache_name && !strcmp(cache_name, first)) {
-                       any_files = 1;
-                       src[0] = active_cache[*indpos];
-                       remove_cache_entry_at(*indpos);
-               }
-
-               for (i = 0; i < len; i++) {
-                       struct cache_entry *ce;
-
-                       if (!posns[i] ||
-                           (posns[i] != &df_conflict_list &&
-                            strcmp(first, posns[i]->name))) {
-                               continue;
-                       }
-
-                       if (posns[i] == &df_conflict_list) {
-                               src[i + merge] = &df_conflict_entry;
-                               continue;
-                       }
-
-                       if (posns[i]->directory) {
-                               struct tree *tree = lookup_tree(posns[i]->sha1);
-                               any_dirs = 1;
-                               parse_tree(tree);
-                               subposns[i] = create_tree_entry_list(tree);
-                               posns[i] = posns[i]->next;
-                               src[i + merge] = &df_conflict_entry;
-                               continue;
-                       }
-
-                       if (!merge)
-                               ce_stage = 0;
-                       else if (i + 1 < head_idx)
-                               ce_stage = 1;
-                       else if (i + 1 > head_idx)
-                               ce_stage = 3;
-                       else
-                               ce_stage = 2;
-
-                       ce = xcalloc(1, ce_size);
-                       ce->ce_mode = create_ce_mode(posns[i]->mode);
-                       ce->ce_flags = create_ce_flags(baselen + pathlen,
-                                                      ce_stage);
-                       memcpy(ce->name, base, baselen);
-                       memcpy(ce->name + baselen, first, pathlen + 1);
-
-                       any_files = 1;
-
-                       memcpy(ce->sha1, posns[i]->sha1, 20);
-                       src[i + merge] = ce;
-                       subposns[i] = &df_conflict_list;
-                       posns[i] = posns[i]->next;
-               }
-               if (any_files) {
-                       if (merge) {
-                               int ret;
-
-#if DBRT_DEBUG > 1
-                               printf("%s:\n", first);
-                               for (i = 0; i < src_size; i++) {
-                                       printf(" %d ", i);
-                                       if (src[i])
-                                               printf("%s\n", sha1_to_hex(src[i]->sha1));
-                                       else
-                                               printf("\n");
-                               }
-#endif
-                               ret = fn(src);
-                               
-#if DBRT_DEBUG > 1
-                               printf("Added %d entries\n", ret);
-#endif
-                               *indpos += ret;
-                       } else {
-                               for (i = 0; i < src_size; i++) {
-                                       if (src[i]) {
-                                               add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
-                                       }
-                               }
-                       }
-               }
-               if (any_dirs) {
-                       char *newbase = xmalloc(baselen + 2 + pathlen);
-                       memcpy(newbase, base, baselen);
-                       memcpy(newbase + baselen, first, pathlen);
-                       newbase[baselen + pathlen] = '/';
-                       newbase[baselen + pathlen + 1] = '\0';
-                       if (unpack_trees_rec(subposns, len, newbase, fn,
-                                            indpos))
-                               return -1;
-                       free(newbase);
-               }
-               free(subposns);
-               free(src);
-       } while (1);
-}
-
 static void reject_merge(struct cache_entry *ce)
 {
-       die("Entry '%s' would be overwritten by merge. Cannot merge.", 
+       die("Entry '%s' would be overwritten by merge. Cannot merge.",
            ce->name);
 }
 
-/* Unlink the last component and attempt to remove leading
- * directories, in case this unlink is the removal of the
- * last entry in the directory -- empty directories are removed.
- */
-static void unlink_entry(char *name)
-{
-       char *cp, *prev;
-
-       if (unlink(name))
-               return;
-       prev = NULL;
-       while (1) {
-               int status;
-               cp = strrchr(name, '/');
-               if (prev)
-                       *prev = '/';
-               if (!cp)
-                       break;
-
-               *cp = 0;
-               status = rmdir(name);
-               if (status) {
-                       *cp = '/';
-                       break;
-               }
-               prev = cp;
-       }
-}
-
-static void progress_interval(int signum)
-{
-       progress_update = 1;
-}
-
-static void setup_progress_signal(void)
-{
-       struct sigaction sa;
-       struct itimerval v;
-
-       memset(&sa, 0, sizeof(sa));
-       sa.sa_handler = progress_interval;
-       sigemptyset(&sa.sa_mask);
-       sa.sa_flags = SA_RESTART;
-       sigaction(SIGALRM, &sa, NULL);
-
-       v.it_interval.tv_sec = 1;
-       v.it_interval.tv_usec = 0;
-       v.it_value = v.it_interval;
-       setitimer(ITIMER_REAL, &v, NULL);
-}
-
-static struct checkout state;
-static void check_updates(struct cache_entry **src, int nr)
-{
-       unsigned short mask = htons(CE_UPDATE);
-       unsigned last_percent = 200, cnt = 0, total = 0;
-
-       if (update && verbose_update) {
-               for (total = cnt = 0; cnt < nr; cnt++) {
-                       struct cache_entry *ce = src[cnt];
-                       if (!ce->ce_mode || ce->ce_flags & mask)
-                               total++;
-               }
-
-               /* Don't bother doing this for very small updates */
-               if (total < 250)
-                       total = 0;
-
-               if (total) {
-                       fprintf(stderr, "Checking files out...\n");
-                       setup_progress_signal();
-                       progress_update = 1;
-               }
-               cnt = 0;
-       }
-
-       while (nr--) {
-               struct cache_entry *ce = *src++;
-
-               if (total) {
-                       if (!ce->ce_mode || ce->ce_flags & mask) {
-                               unsigned percent;
-                               cnt++;
-                               percent = (cnt * 100) / total;
-                               if (percent != last_percent ||
-                                   progress_update) {
-                                       fprintf(stderr, "%4u%% (%u/%u) done\r",
-                                               percent, cnt, total);
-                                       last_percent = percent;
-                                       progress_update = 0;
-                               }
-                       }
-               }
-               if (!ce->ce_mode) {
-                       if (update)
-                               unlink_entry(ce->name);
-                       continue;
-               }
-               if (ce->ce_flags & mask) {
-                       ce->ce_flags &= ~mask;
-                       if (update)
-                               checkout_entry(ce, &state, NULL);
-               }
-       }
-       if (total) {
-               signal(SIGALRM, SIG_IGN);
-               fputc('\n', stderr);
-       }
-}
-
-static int unpack_trees(merge_fn_t fn)
-{
-       int indpos = 0;
-       unsigned len = object_list_length(trees);
-       struct tree_entry_list **posns;
-       int i;
-       struct object_list *posn = trees;
-       merge_size = len;
-
-       if (len) {
-               posns = xmalloc(len * sizeof(struct tree_entry_list *));
-               for (i = 0; i < len; i++) {
-                       posns[i] = create_tree_entry_list((struct tree *) posn->item);
-                       posn = posn->next;
-               }
-               if (unpack_trees_rec(posns, len, prefix ? prefix : "",
-                                    fn, &indpos))
-                       return -1;
-       }
-
-       if (trivial_merges_only && nontrivial_merge)
-               die("Merge requires file-level merging");
-
-       check_updates(active_cache, active_nr);
-       return 0;
-}
-
 static int list_tree(unsigned char *sha1)
 {
        struct tree *tree = parse_tree_indirect(sha1);
@@ -440,11 +46,12 @@ static int same(struct cache_entry *a, struct cache_entry *b)
  * 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)
+static void verify_uptodate(struct cache_entry *ce,
+               struct unpack_trees_options *o)
 {
        struct stat st;
 
-       if (index_only || reset)
+       if (o->index_only || o->reset)
                return;
 
        if (!lstat(ce->name, &st)) {
@@ -453,7 +60,7 @@ static void verify_uptodate(struct cache_entry *ce)
                        return;
                errno = 0;
        }
-       if (reset) {
+       if (o->reset) {
                ce->ce_flags |= htons(CE_UPDATE);
                return;
        }
@@ -472,18 +79,20 @@ static void invalidate_ce_path(struct cache_entry *ce)
  * 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)
+static void verify_absent(const char *path, const char *action,
+               struct unpack_trees_options *o)
 {
        struct stat st;
 
-       if (index_only || reset || !update)
+       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)
+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) {
@@ -497,12 +106,12 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
                if (same(old, merge)) {
                        *merge = *old;
                } else {
-                       verify_uptodate(old);
+                       verify_uptodate(old, o);
                        invalidate_ce_path(old);
                }
        }
        else {
-               verify_absent(merge->name, "overwritten");
+               verify_absent(merge->name, "overwritten", o);
                invalidate_ce_path(merge);
        }
 
@@ -511,12 +120,13 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
        return 1;
 }
 
-static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
+static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
+               struct unpack_trees_options *o)
 {
        if (old)
-               verify_uptodate(old);
+               verify_uptodate(old, o);
        else
-               verify_absent(ce->name, "removed");
+               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);
@@ -545,11 +155,12 @@ static void show_stage_entry(FILE *o,
 }
 #endif
 
-static int threeway_merge(struct cache_entry **stages)
+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[head_idx + 1];
+       struct cache_entry *head;
+       struct cache_entry *remote = stages[o->head_idx + 1];
        int count;
        int head_match = 0;
        int remote_match = 0;
@@ -562,7 +173,7 @@ static int threeway_merge(struct cache_entry **stages)
        int no_anc_exists = 1;
        int i;
 
-       for (i = 1; i < head_idx; i++) {
+       for (i = 1; i < o->head_idx; i++) {
                if (!stages[i])
                        any_anc_missing = 1;
                else {
@@ -573,14 +184,14 @@ static int threeway_merge(struct cache_entry **stages)
        }
 
        index = stages[0];
-       head = stages[head_idx];
+       head = stages[o->head_idx];
 
-       if (head == &df_conflict_entry) {
+       if (head == &o->df_conflict_entry) {
                df_conflict_head = 1;
                head = NULL;
        }
 
-       if (remote == &df_conflict_entry) {
+       if (remote == &o->df_conflict_entry) {
                df_conflict_remote = 1;
                remote = NULL;
        }
@@ -596,7 +207,7 @@ static int threeway_merge(struct cache_entry **stages)
         * and #14.
         */
        if (!same(remote, head)) {
-               for (i = 1; i < head_idx; i++) {
+               for (i = 1; i < o->head_idx; i++) {
                        if (same(stages[i], head)) {
                                head_match = i;
                        }
@@ -614,7 +225,7 @@ static int threeway_merge(struct cache_entry **stages)
        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);
+               return merged_entry(remote, index, o);
        }
        /*
         * If we have an entry in the index cache, then we want to
@@ -627,10 +238,10 @@ static int threeway_merge(struct cache_entry **stages)
        if (head) {
                /* #5ALT, #15 */
                if (same(head, remote))
-                       return merged_entry(head, index);
+                       return merged_entry(head, index, o);
                /* #13, #3ALT */
                if (!df_conflict_remote && remote_match && !head_match)
-                       return merged_entry(head, index);
+                       return merged_entry(head, index, o);
        }
 
        /* #1 */
@@ -640,7 +251,7 @@ static int threeway_merge(struct cache_entry **stages)
        /* Under the new "aggressive" rule, we resolve mostly trivial
         * cases that we historically had git-merge-one-file resolve.
         */
-       if (aggressive) {
+       if (o->aggressive) {
                int head_deleted = !head && !df_conflict_head;
                int remote_deleted = !remote && !df_conflict_remote;
                /*
@@ -651,35 +262,35 @@ static int threeway_merge(struct cache_entry **stages)
                    (head_deleted && remote && remote_match) ||
                    (remote_deleted && head && head_match)) {
                        if (index)
-                               return deleted_entry(index, index);
+                               return deleted_entry(index, index, o);
                        else if (path)
-                               verify_absent(path, "removed");
+                               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);
+                       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. 
+        * conflict resolution files.
         */
        if (index) {
-               verify_uptodate(index);
+               verify_uptodate(index, o);
        }
        else if (path)
-               verify_absent(path, "overwritten");
+               verify_absent(path, "overwritten", o);
 
-       nontrivial_merge = 1;
+       o->nontrivial_merge = 1;
 
        /* #2, #3, #4, #6, #7, #9, #11. */
        count = 0;
        if (!head_match || !remote_match) {
-               for (i = 1; i < head_idx; i++) {
+               for (i = 1; i < o->head_idx; i++) {
                        if (stages[i]) {
                                keep_entry(stages[i]);
                                count++;
@@ -708,14 +319,15 @@ static int threeway_merge(struct cache_entry **stages)
  * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
  *
  */
-static int twoway_merge(struct cache_entry **src)
+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 (merge_size != 2)
+       if (o->merge_size != 2)
                return error("Cannot do a twoway merge of %d trees",
-                            merge_size);
+                            o->merge_size);
 
        if (current) {
                if ((!oldtree && !newtree) || /* 4 and 5 */
@@ -730,12 +342,12 @@ static int twoway_merge(struct cache_entry **src)
                }
                else if (oldtree && !newtree && same(current, oldtree)) {
                        /* 10 or 11 */
-                       return deleted_entry(oldtree, current);
+                       return deleted_entry(oldtree, current, o);
                }
                else if (oldtree && newtree &&
                         same(current, oldtree) && !same(current, newtree)) {
                        /* 20 or 21 */
-                       return merged_entry(newtree, current);
+                       return merged_entry(newtree, current, o);
                }
                else {
                        /* all other failures */
@@ -749,9 +361,9 @@ static int twoway_merge(struct cache_entry **src)
                }
        }
        else if (newtree)
-               return merged_entry(newtree, current);
+               return merged_entry(newtree, current, o);
        else
-               return deleted_entry(oldtree, current);
+               return deleted_entry(oldtree, current, o);
 }
 
 /*
@@ -760,20 +372,21 @@ static int twoway_merge(struct cache_entry **src)
  * 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)
+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 (merge_size != 1)
+       if (o->merge_size != 1)
                return error("Cannot do a bind merge of %d trees\n",
-                            merge_size);
+                            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);
+               return merged_entry(a, NULL, o);
 }
 
 /*
@@ -782,19 +395,20 @@ static int bind_merge(struct cache_entry **src)
  * The rule is:
  * - take the stat information from stage0, take the data from stage1
  */
-static int oneway_merge(struct cache_entry **src)
+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 (merge_size != 1)
+       if (o->merge_size != 1)
                return error("Cannot do a oneway merge of %d trees",
-                            merge_size);
+                            o->merge_size);
 
        if (!a)
-               return deleted_entry(old, old);
+               return deleted_entry(old, old, o);
        if (old && same(old, a)) {
-               if (reset) {
+               if (o->reset) {
                        struct stat st;
                        if (lstat(old->name, &st) ||
                            ce_match_stat(old, &st, 1))
@@ -802,7 +416,7 @@ static int oneway_merge(struct cache_entry **src)
                }
                return keep_entry(old);
        }
-       return merged_entry(a, old);
+       return merged_entry(a, old, o);
 }
 
 static int read_cache_unmerged(void)
@@ -874,14 +488,12 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
 {
        int i, newfd, stage = 0;
        unsigned char sha1[20];
-       merge_fn_t fn = NULL;
+       struct unpack_trees_options opts;
 
-       df_conflict_list.next = &df_conflict_list;
-       state.base_dir = "";
-       state.force = 1;
-       state.quiet = 1;
-       state.refresh_cache = 1;
+       memset(&opts, 0, sizeof(opts));
+       opts.head_idx = -1;
 
+       setup_git_directory();
        git_config(git_default_config);
 
        newfd = hold_lock_file_for_update(&lock_file, get_index_file());
@@ -890,8 +502,6 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
 
        git_config(git_default_config);
 
-       merge = 0;
-       reset = 0;
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
 
@@ -899,12 +509,12 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                 * the working tree.
                 */
                if (!strcmp(arg, "-u")) {
-                       update = 1;
+                       opts.update = 1;
                        continue;
                }
 
                if (!strcmp(arg, "-v")) {
-                       verbose_update = 1;
+                       opts.verbose_update = 1;
                        continue;
                }
 
@@ -912,7 +522,7 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                 * not even look at the working tree.
                 */
                if (!strcmp(arg, "-i")) {
-                       index_only = 1;
+                       opts.index_only = 1;
                        continue;
                }
 
@@ -921,10 +531,10 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                 * given subdirectory.
                 */
                if (!strncmp(arg, "--prefix=", 9)) {
-                       if (stage || merge || prefix)
+                       if (stage || opts.merge || opts.prefix)
                                usage(read_tree_usage);
-                       prefix = arg + 9;
-                       merge = 1;
+                       opts.prefix = arg + 9;
+                       opts.merge = 1;
                        stage = 1;
                        if (read_cache_unmerged())
                                die("you need to resolve your current index first");
@@ -936,38 +546,38 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                 * correspond to them.
                 */
                if (!strcmp(arg, "--reset")) {
-                       if (stage || merge || prefix)
+                       if (stage || opts.merge || opts.prefix)
                                usage(read_tree_usage);
-                       reset = 1;
-                       merge = 1;
+                       opts.reset = 1;
+                       opts.merge = 1;
                        stage = 1;
                        read_cache_unmerged();
                        continue;
                }
 
                if (!strcmp(arg, "--trivial")) {
-                       trivial_merges_only = 1;
+                       opts.trivial_merges_only = 1;
                        continue;
                }
 
                if (!strcmp(arg, "--aggressive")) {
-                       aggressive = 1;
+                       opts.aggressive = 1;
                        continue;
                }
 
                /* "-m" stands for "merge", meaning we start in stage 1 */
                if (!strcmp(arg, "-m")) {
-                       if (stage || merge || prefix)
+                       if (stage || opts.merge || opts.prefix)
                                usage(read_tree_usage);
                        if (read_cache_unmerged())
                                die("you need to resolve your current index first");
                        stage = 1;
-                       merge = 1;
+                       opts.merge = 1;
                        continue;
                }
 
                /* using -u and -i at the same time makes no sense */
-               if (1 < index_only + update)
+               if (1 < opts.index_only + opts.update)
                        usage(read_tree_usage);
 
                if (get_sha1(arg, sha1))
@@ -976,52 +586,53 @@ int cmd_read_tree(int argc, const char **argv, const char *prefix)
                        die("failed to unpack tree object %s", arg);
                stage++;
        }
-       if ((update||index_only) && !merge)
+       if ((opts.update||opts.index_only) && !opts.merge)
                usage(read_tree_usage);
 
-       if (prefix) {
-               int pfxlen = strlen(prefix);
+       if (opts.prefix) {
+               int pfxlen = strlen(opts.prefix);
                int pos;
-               if (prefix[pfxlen-1] != '/')
+               if (opts.prefix[pfxlen-1] != '/')
                        die("prefix must end with /");
                if (stage != 2)
                        die("binding merge takes only one tree");
-               pos = cache_name_pos(prefix, pfxlen);
+               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, prefix, pfxlen))
-                       die("subdirectory '%s' already exists.", prefix);
-               pos = cache_name_pos(prefix, pfxlen-1);
+                   !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, prefix);
+                       die("file '%.*s' already exists.",
+                                       pfxlen-1, opts.prefix);
        }
 
-       if (merge) {
+       if (opts.merge) {
                if (stage < 2)
                        die("just how do you expect me to merge %d trees?", stage-1);
                switch (stage - 1) {
                case 1:
-                       fn = prefix ? bind_merge : oneway_merge;
+                       opts.fn = opts.prefix ? bind_merge : oneway_merge;
                        break;
                case 2:
-                       fn = twoway_merge;
+                       opts.fn = twoway_merge;
                        break;
                case 3:
                default:
-                       fn = threeway_merge;
+                       opts.fn = threeway_merge;
                        cache_tree_free(&active_cache_tree);
                        break;
                }
 
                if (stage - 1 >= 3)
-                       head_idx = stage - 2;
+                       opts.head_idx = stage - 2;
                else
-                       head_idx = 1;
+                       opts.head_idx = 1;
        }
 
-       unpack_trees(fn);
+       unpack_trees(trees, &opts);
 
        /*
         * When reading only one tree (either the most basic form,
@@ -1029,7 +640,7 @@ 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 && !prefix && (!merge || (stage == 2))) {
+       if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
                cache_tree_free(&active_cache_tree);
                prime_cache_tree();
        }