1 files changed, 122 insertions, 18 deletions

diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 716f792514..0c6ba3d8a5 100644
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -9,6 +9,7 @@
 
 #include "object.h"
 #include "tree.h"
+#include "tree-walk.h"
 #include "cache-tree.h"
 #include <sys/time.h>
 #include <signal.h>
@@ -23,13 +24,24 @@ 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 = { 
+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 = {
@@ -39,7 +51,35 @@ static struct tree_entry_list df_conflict_list = {
 
 typedef int (*merge_fn_t)(struct cache_entry **src);
 
-static int entcmp(char *name1, int dir1, char *name2, int dir2)
+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);
@@ -67,7 +107,7 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
 	int src_size = len + 1;
 	do {
 		int i;
-		char *first;
+		const char *first;
 		int firstdir = 0;
 		int pathlen;
 		unsigned ce_size;
@@ -161,9 +201,10 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
 			}
 
 			if (posns[i]->directory) {
+				struct tree *tree = lookup_tree(posns[i]->sha1);
 				any_dirs = 1;
-				parse_tree(posns[i]->item.tree);
-				subposns[i] = posns[i]->item.tree->entries;
+				parse_tree(tree);
+				subposns[i] = create_tree_entry_list(tree);
 				posns[i] = posns[i]->next;
 				src[i + merge] = &df_conflict_entry;
 				continue;
@@ -187,7 +228,7 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
 
 			any_files = 1;
 
-			memcpy(ce->sha1, posns[i]->item.any->sha1, 20);
+			memcpy(ce->sha1, posns[i]->sha1, 20);
 			src[i + merge] = ce;
 			subposns[i] = &df_conflict_list;
 			posns[i] = posns[i]->next;
@@ -368,10 +409,11 @@ static int unpack_trees(merge_fn_t fn)
 	if (len) {
 		posns = xmalloc(len * sizeof(struct tree_entry_list *));
 		for (i = 0; i < len; i++) {
-			posns[i] = ((struct tree *) posn->item)->entries;
+			posns[i] = create_tree_entry_list((struct tree *) posn->item);
 			posn = posn->next;
 		}
-		if (unpack_trees_rec(posns, len, "", fn, &indpos))
+		if (unpack_trees_rec(posns, len, prefix ? prefix : "",
+				     fn, &indpos))
 			return -1;
 	}
 
@@ -721,6 +763,28 @@ static int twoway_merge(struct cache_entry **src)
 }
 
 /*
+ * 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 cache_entry *old = src[0];
+	struct cache_entry *a = src[1];
+
+	if (merge_size != 1)
+		return error("Cannot do a bind merge of %d trees\n",
+			     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);
+}
+
+/*
  * One-way merge.
  *
  * The rule is:
@@ -735,8 +799,10 @@ static int oneway_merge(struct cache_entry **src)
 		return error("Cannot do a oneway merge of %d trees",
 			     merge_size);
 
-	if (!a)
+	if (!a) {
+		invalidate_ce_path(old);
 		return deleted_entry(old, old);
+	}
 	if (old && same(old, a)) {
 		if (reset) {
 			struct stat st;
@@ -774,19 +840,23 @@ static int read_cache_unmerged(void)
 
 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 {
-	struct tree_entry_list *ent;
+	struct tree_desc desc;
+	struct name_entry entry;
 	int cnt;
 
 	memcpy(it->sha1, tree->object.sha1, 20);
-	for (cnt = 0, ent = tree->entries; ent; ent = ent->next) {
-		if (!ent->directory)
+	desc.buf = tree->buffer;
+	desc.size = tree->size;
+	cnt = 0;
+	while (tree_entry(&desc, &entry)) {
+		if (!S_ISDIR(entry.mode))
 			cnt++;
 		else {
 			struct cache_tree_sub *sub;
-			struct tree *subtree = (struct tree *)ent->item.tree;
+			struct tree *subtree = lookup_tree(entry.sha1);
 			if (!subtree->object.parsed)
 				parse_tree(subtree);
-			sub = cache_tree_sub(it, ent->name);
+			sub = cache_tree_sub(it, entry.path);
 			sub->cache_tree = cache_tree();
 			prime_cache_tree_rec(sub->cache_tree, subtree);
 			cnt += sub->cache_tree->entry_count;
@@ -805,7 +875,7 @@ static void prime_cache_tree(void)
 
 }
 
-static const char read_tree_usage[] = "git-read-tree (<sha> | -m [--aggressive] [-u | -i] <sha1> [<sha2> [<sha3>]])";
+static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <sha1> [<sha2> [<sha3>]])";
 
 static struct cache_file cache_file;
 
@@ -850,9 +920,24 @@ int cmd_read_tree(int argc, const char **argv, char **envp)
 			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 (stage || merge || prefix)
+				usage(read_tree_usage);
+			prefix = arg + 9;
+			merge = 1;
+			stage = 1;
+			if (read_cache_unmerged())
+				die("you need to resolve your current index first");
+			continue;
+		}
+
 		/* This differs from "-m" in that we'll silently ignore unmerged entries */
 		if (!strcmp(arg, "--reset")) {
-			if (stage || merge)
+			if (stage || merge || prefix)
 				usage(read_tree_usage);
 			reset = 1;
 			merge = 1;
@@ -873,7 +958,7 @@ int cmd_read_tree(int argc, const char **argv, char **envp)
 
 		/* "-m" stands for "merge", meaning we start in stage 1 */
 		if (!strcmp(arg, "-m")) {
-			if (stage || merge)
+			if (stage || merge || prefix)
 				usage(read_tree_usage);
 			if (read_cache_unmerged())
 				die("you need to resolve your current index first");
@@ -895,12 +980,31 @@ int cmd_read_tree(int argc, const char **argv, char **envp)
 	if ((update||index_only) && !merge)
 		usage(read_tree_usage);
 
+	if (prefix) {
+		int pfxlen = strlen(prefix);
+		int pos;
+		if (prefix[pfxlen-1] != '/')
+			die("prefix must end with /");
+		if (stage != 2)
+			die("binding merge takes only one tree");
+		pos = cache_name_pos(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);
+		if (0 <= pos)
+			die("file '%.*s' already exists.", pfxlen-1, prefix);
+	}
+
 	if (merge) {
 		if (stage < 2)
 			die("just how do you expect me to merge %d trees?", stage-1);
 		switch (stage - 1) {
 		case 1:
-			fn = oneway_merge;
+			fn = prefix ? bind_merge : oneway_merge;
 			break;
 		case 2:
 			fn = twoway_merge;