diff --git a/builtin/clone.c b/builtin/clone.c index 073e6323d7..4b80fa0870 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -357,8 +357,27 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest, if (unlink(dest->buf) && errno != ENOENT) die_errno(_("failed to unlink '%s'"), dest->buf); if (!option_no_hardlinks) { - if (!link(src->buf, dest->buf)) + if (!link(src->buf, dest->buf)) { + struct stat st; + + /* + * Sanity-check whether the created hardlink + * actually links to the expected file now. This + * catches time-of-check-time-of-use bugs in + * case the source file was meanwhile swapped. + */ + if (lstat(dest->buf, &st)) + die(_("hardlink cannot be checked at '%s'"), dest->buf); + if (st.st_mode != iter->st.st_mode || + st.st_ino != iter->st.st_ino || + st.st_dev != iter->st.st_dev || + st.st_size != iter->st.st_size || + st.st_uid != iter->st.st_uid || + st.st_gid != iter->st.st_gid) + die(_("hardlink different from source at '%s'"), dest->buf); + continue; + } if (option_local > 0) die_errno(_("failed to create link '%s'"), dest->buf); option_no_hardlinks = 1;