match-trees: compute buffer offset correctly when splicing

Currently, the struct object_id pointer returned from tree_entry_extract
lives directly inside the parsed tree buffer. In a future commit, this
will change so that it instead points to a dedicated struct member.
Since in this code path, we want to modify the buffer directly, compute
the buffer offset we want to modify by using the pointer to the path
instead.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/match-trees.c b/match-trees.c
index 2b6d31ef9d35d9422e7ef90792651dcb7a2f9189..feca48a5fd2ab409e198266ac66ce71c49453af2 100644 (file)
--- a/match-trees.c
+++ b/match-trees.c
@@ -199,15 +199,16 @@ static int splice_tree(const struct object_id *oid1, const char *prefix,
        while (desc.size) {
                const char *name;
                unsigned mode;
-               const struct object_id *oid;
 
-               oid = tree_entry_extract(&desc, &name, &mode);
+               tree_entry_extract(&desc, &name, &mode);
                if (strlen(name) == toplen &&
                    !memcmp(name, prefix, toplen)) {
                        if (!S_ISDIR(mode))
                                die("entry %s in tree %s is not a tree", name,
                                    oid_to_hex(oid1));
-                       rewrite_here = (struct object_id *)oid;
+                       rewrite_here = (struct object_id *)(desc.entry.path +
+                                                           strlen(desc.entry.path) +
+                                                           1);
                        break;
                }
                update_tree_entry(&desc);