Fix a bug in Dets concerning repair of almost full tables

A Dets table with sufficiently large buckets could not always be repaired.
(Reported by Gordon Guthrie.)

The format of Dets files has been modified. When downgrading tables
created with the new system will be repaired. Otherwise the
modification should not be noticeable.

1 files changed, 7 insertions, 9 deletions

diff --git a/lib/stdlib/src/dets_v8.erl b/lib/stdlib/src/dets_v8.erl
index cdd38d5604..3e962a1c8b 100644
--- a/lib/stdlib/src/dets_v8.erl
+++ b/lib/stdlib/src/dets_v8.erl
@@ -21,7 +21,7 @@
 %% Dets files, implementation part. This module handles versions up to
 %% and including 8(c). To be called from dets.erl only.
 
--export([constants/0, mark_dirty/1, read_file_header/2,
+-export([mark_dirty/1, read_file_header/2,
          check_file_header/2, do_perform_save/1, initiate_file/11,
          init_freelist/2, fsck_input/4,
          bulk_input/3, output_objs/4, write_cache/1, may_grow/3,
@@ -196,10 +196,6 @@
 %%-define(DEBUGF(X,Y), io:format(X, Y)).
 -define(DEBUGF(X,Y), void).
 
-%% {Bump}
-constants() ->
-    {?BUMP, ?BASE}.
-
 %% -> ok | throw({NewHead,Error})
 mark_dirty(Head) ->
     Dirty = [{?CLOSED_PROPERLY_POS, <<?NOT_PROPERLY_CLOSED:32>>}],
@@ -308,8 +304,9 @@ init_freelist(Head, {convert_freelist,_Version}) ->
     Pos = Head#head.freelists_p,
     case catch prterm(Head, Pos, ?OHDSZ) of
 	{0, _Sz, Term}  ->
-	    FreeList = lists:reverse(Term),
-	    dets_utils:init_slots_from_old_file(FreeList, Ftab);
+	    FreeList1 = lists:reverse(Term),
+            FreeList = dets_utils:init_slots_from_old_file(FreeList1, Ftab),
+            Head#head{freelists = FreeList, base = ?BASE};
 	_ ->
 	    throw({error, {bad_freelists, Head#head.filename}})
     end;
@@ -318,7 +315,7 @@ init_freelist(Head, _) ->
     Pos = Head#head.freelists_p,
     case catch prterm(Head, Pos, ?OHDSZ) of
 	{0, _Sz, Term}  ->
-	    Term;
+            Head#head{freelists = Term, base = ?BASE};
 	_ ->
 	    throw({error, {bad_freelists, Head#head.filename}})
     end.
@@ -331,6 +328,7 @@ read_file_header(Fd, FileName) ->
     {ok, EOF} = dets_utils:position_close(Fd, FileName, eof),
     {ok, <<FileSize:32>>} = dets_utils:pread_close(Fd, FileName, EOF-4, 4),
     FH = #fileheader{freelist = Freelist,
+                     fl_base = ?BASE,
 		     cookie = Cookie,
 		     closed_properly = CP,
 		     type = dets_utils:code_to_type(Type2),
@@ -413,7 +411,7 @@ check_file_header(FH, Fd) ->
 	      version = ?FILE_FORMAT_VERSION,
 	      mod = ?MODULE,
 	      bump = ?BUMP,
-	      base = ?BASE},
+	      base = FH#fileheader.fl_base},
 	    {ok, H, ExtraInfo};
 	Error ->
 	    Error