Index: subversion/libsvn_fs_fs/hotcopy.c
===================================================================
--- subversion/libsvn_fs_fs/hotcopy.c	(revision 1564943)
+++ subversion/libsvn_fs_fs/hotcopy.c	(working copy)
@@ -382,12 +382,6 @@ hotcopy_update_current(svn_revnum_t *dst_youngest,
   /* If necessary, get new current next_node and next_copy IDs. */
   if (dst_ffd->format < SVN_FS_FS__MIN_NO_GLOBAL_IDS_FORMAT)
     {
-      /* Make sure NEW_YOUNGEST is a valid revision in DST_FS.
-         Because a crash in hotcopy requires at least a full recovery run,
-         it is safe to temporarily reset the max IDs to 0. */
-      SVN_ERR(svn_fs_fs__write_current(dst_fs, new_youngest, next_node_id,
-                                      next_copy_id, scratch_pool));
-
       SVN_ERR(svn_fs_fs__find_max_ids(dst_fs, new_youngest,
                                       &next_node_id, &next_copy_id,
                                       scratch_pool));
Index: subversion/libsvn_fs_fs/recovery.c
===================================================================
--- subversion/libsvn_fs_fs/recovery.c	(revision 1564943)
+++ subversion/libsvn_fs_fs/recovery.c	(working copy)
@@ -275,6 +275,41 @@ recover_find_max_ids(svn_fs_t *fs,
   return SVN_NO_ERROR;
 }
 
+/* Part of the recovery procedure.  Given an open non-packed revision file
+   REV_FILE for REV, locate the trailer that specifies the offset to the root
+   node-id and store this offset in *ROOT_OFFSET.  Do temporary allocations in
+   POOL. */
+static svn_error_t *
+recover_get_root_offset(apr_off_t *root_offset,
+                        svn_revnum_t rev,
+                        svn_fs_fs__revision_file_t *rev_file,
+                        apr_pool_t *pool)
+{
+  svn_stringbuf_t *trailer = svn_stringbuf_create_ensure(64, pool);
+  apr_off_t offset = 0;
+
+  SVN_ERR_ASSERT(!rev_file->is_packed);
+
+  /* We will assume that the last line containing the two offsets (to the root
+     node-id and to the changed path information) will never be longer than 64
+     characters. */
+  SVN_ERR(svn_io_file_seek(rev_file->file, APR_END, &offset, pool));
+
+  trailer->len = trailer->blocksize-1;
+  offset = offset - trailer->len;
+  SVN_ERR(svn_io_file_seek(rev_file->file, APR_SET, &offset, pool));
+
+  /* Read in this last block, from which we will identify the last line. */
+  SVN_ERR(svn_io_file_read(rev_file->file, trailer->data,
+                           &trailer->len, pool));
+  trailer->data[trailer->len] = 0;
+
+  /* Parse the last line. */
+  SVN_ERR(svn_fs_fs__parse_revision_trailer(root_offset, NULL, trailer, rev));
+
+  return SVN_NO_ERROR;
+}
+
 svn_error_t *
 svn_fs_fs__find_max_ids(svn_fs_t *fs,
                         svn_revnum_t youngest,
@@ -285,16 +320,12 @@ svn_fs_fs__find_max_ids(svn_fs_t *fs,
   fs_fs_data_t *ffd = fs->fsap_data;
   apr_off_t root_offset;
   svn_fs_fs__revision_file_t *rev_file;
-  svn_fs_id_t *root_id;
 
   /* call this function for old repo formats only */
   SVN_ERR_ASSERT(ffd->format < SVN_FS_FS__MIN_NO_GLOBAL_IDS_FORMAT);
 
-  SVN_ERR(svn_fs_fs__rev_get_root(&root_id, fs, youngest, pool));
   SVN_ERR(svn_fs_fs__open_pack_or_rev_file(&rev_file, fs, youngest, pool));
-  SVN_ERR(svn_fs_fs__item_offset(&root_offset, fs, rev_file, youngest, NULL,
-                                 svn_fs_fs__id_item(root_id), pool));
-
+  SVN_ERR(recover_get_root_offset(&root_offset, youngest, rev_file, pool));
   SVN_ERR(recover_find_max_ids(fs, youngest, rev_file, root_offset,
                                max_node_id, max_copy_id, pool));
   SVN_ERR(svn_fs_fs__close_revision_file(rev_file));
Index: subversion/tests/cmdline/svnadmin_tests.py
===================================================================
--- subversion/tests/cmdline/svnadmin_tests.py	(revision 1564943)
+++ subversion/tests/cmdline/svnadmin_tests.py	(working copy)
@@ -828,10 +828,14 @@ _0.0.t1-1 add false false /A/B/E/bravo
 
 #----------------------------------------------------------------------
 
-@SkipUnless(svntest.main.is_fs_type_fsfs)
-def recover_fsfs(sbox):
-  "recover a repository (FSFS only)"
-  sbox.build()
+# Helper for two test functions.
+def corrupt_and_recover_db_current(sbox, minor_version=None):
+  """Build up a MINOR_VERSION sanbox and test different recovery scenarios
+  with missing, out-of-date or even corrupt db/current files.  Recovery should
+  behave the same way with all values of MINOR_VERSION, hence this helper
+  containing the common code that allows us to check it."""
+
+  sbox.build(minor_version=minor_version)
   current_path = os.path.join(sbox.repo_dir, 'db', 'current')
 
   # Commit up to r3, so we can test various recovery scenarios.
@@ -906,6 +910,24 @@ _0.0.t1-1 add false false /A/B/E/bravo
     "Contents of db/current is unexpected.",
     'db/current', expected_current_contents, actual_current_contents)
 
+
+@SkipUnless(svntest.main.is_fs_type_fsfs)
+def fsfs_recover_db_current(sbox):
+  "fsfs recover db/current"
+  corrupt_and_recover_db_current(sbox)
+
+
+@SkipUnless(svntest.main.is_fs_type_fsfs)
+def fsfs_recover_old_db_current(sbox):
+  "fsfs recover db/current --compatible-version=1.3"
+
+  # Around trunk@1564943, 'svnadmin recover' wrongly errored out
+  # for the --compatible-version=1.3 repositories with missing or
+  # invalid db/current file:
+  # svnadmin: E160006: No such revision 1
+
+  corrupt_and_recover_db_current(sbox, minor_version=3)
+
 #----------------------------------------------------------------------
 @Issue(2983)
 def load_with_parent_dir(sbox):
@@ -2291,7 +2313,8 @@ test_list = [ None,
               setrevprop,
               verify_windows_paths_in_repos,
               verify_incremental_fsfs,
-              recover_fsfs,
+              fsfs_recover_db_current,
+              fsfs_recover_old_db_current,
               load_with_parent_dir,
               set_uuid,
               reflect_dropped_renumbered_revs,