revision.c: explain what tree_difference does

diff --git a/cache-tree.c b/cache-tree.c
index a880c97b38e7d36f2a45a1743e9565cc1e58280d..9b73c8669a0946c3bcbf1de777e9acd4cd34bcae 100644 (file)
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -2,7 +2,9 @@
 #include "tree.h"
 #include "cache-tree.h"
 
+#ifndef DEBUG
 #define DEBUG 0
+#endif
 
 struct cache_tree *cache_tree(void)
 {
@@ -280,6 +282,8 @@ static int update_one(struct cache_tree *it,
                                    baselen + sublen + 1,
                                    missing_ok,
                                    dryrun);
+               if (subcnt < 0)
+                       return subcnt;
                i += subcnt - 1;
                sub->used = 1;
        }
@@ -335,7 +339,7 @@ static int update_one(struct cache_tree *it,
                offset += sprintf(buffer + offset,
                                  "%o %.*s", mode, entlen, path + baselen);
                buffer[offset++] = 0;
-               memcpy(buffer + offset, sha1, 20);
+               hashcpy((unsigned char*)buffer + offset, sha1);
                offset += 20;
 
 #if DEBUG
@@ -344,12 +348,8 @@ static int update_one(struct cache_tree *it,
 #endif
        }
 
-       if (dryrun) {
-               unsigned char hdr[200];
-               int hdrlen;
-               write_sha1_file_prepare(buffer, offset, tree_type, it->sha1,
-                                       hdr, &hdrlen);
-       }
+       if (dryrun)
+               hash_sha1_file(buffer, offset, tree_type, it->sha1);
        else
                write_sha1_file(buffer, offset, tree_type, it->sha1);
        free(buffer);
@@ -412,7 +412,7 @@ static void *write_one(struct cache_tree *it,
 #endif
 
        if (0 <= it->entry_count) {
-               memcpy(buffer + *offset, it->sha1, 20);
+               hashcpy((unsigned char*)buffer + *offset, it->sha1);
                *offset += 20;
        }
        for (i = 0; i < it->subtree_nr; i++) {
@@ -478,7 +478,7 @@ static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
        if (0 <= it->entry_count) {
                if (size < 20)
                        goto free_return;
-               memcpy(it->sha1, buf, 20);
+               hashcpy(it->sha1, (unsigned char*)buf);
                buf += 20;
                size -= 20;
        }
@@ -529,3 +529,29 @@ struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
                return NULL; /* not the whole tree */
        return read_one(&buffer, &size);
 }
+
+struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
+{
+       while (*path) {
+               const char *slash;
+               struct cache_tree_sub *sub;
+
+               slash = strchr(path, '/');
+               if (!slash)
+                       slash = path + strlen(path);
+               /* between path and slash is the name of the
+                * subtree to look for.
+                */
+               sub = find_subtree(it, path, slash - path, 0);
+               if (!sub)
+                       return NULL;
+               it = sub->cache_tree;
+               if (slash)
+                       while (*slash && *slash == '/')
+                               slash++;
+               if (!slash || !*slash)
+                       return it; /* prefix ended with slashes */
+               path = slash;
+       }
+       return it;
+}