From a17ee35004a5904c46ae24544bf0cab751f4a63b Mon Sep 17 00:00:00 2001
From: terrencehan <isterrence@gmail.com>
Date: Thu, 19 Jun 2014 11:08:23 +0800
Subject: [PATCH] Fix upgrade error

---
 src/rebar_rel_utils.erl        | 29 ++++++++++++++++++++++++++---
 src/rebar_upgrade.erl          | 17 +++++++++++------
 test/upgrade_project/README.md |  5 +++++
 3 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/src/rebar_rel_utils.erl b/src/rebar_rel_utils.erl
index 5d99948..7b08d54 100644
--- a/src/rebar_rel_utils.erl
+++ b/src/rebar_rel_utils.erl
@@ -35,6 +35,7 @@
          get_rel_apps/2,
          get_previous_release_path/1,
          get_rel_file_path/2,
+         get_rel_file_path/3,
          load_config/2,
          get_sys_tuple/1,
          get_excl_lib_tuple/1,
@@ -106,9 +107,18 @@ get_rel_apps(Name, Path) ->
 
 %% Get rel file path from name and path
 get_rel_file_path(Name, Path) ->
-    [RelFile] = filelib:wildcard(filename:join([Path, "releases", "*",
-                                                Name ++ ".rel"])),
-    RelFile.
+    PVer = get_permanent_version(Path),
+    get_rel_file_path(Name, Path, PVer).
+
+get_rel_file_path(Name, Path, Version) ->
+    Dir   = filename:join([Path, "releases", Version]),
+    Path1 = filename:join([Dir, Name ++ "_" ++ Version ++".rel"]),
+    Path2 = filename:join([Dir, Name ++ ".rel"]),
+    case {filelib:is_file(Path1), filelib:is_file(Path2)} of
+        {true, _} -> Path1;
+        {_, true} -> Path2;
+        _ -> ?ABORT("can not find .rel file for version ~p", [Version])
+    end.
 
 %% Get the previous release path from a global variable
 get_previous_release_path(Config) ->
@@ -244,3 +254,16 @@ expand_rel_version(Config, {rel, Name, Version, Apps}, Dir) ->
     {NewConfig, {rel, Name, VsnString, Apps}};
 expand_rel_version(Config, Other, _Dir) ->
     {Config, Other}.
+
+%% get permanent version from start_erl.data
+get_permanent_version(Path) ->
+    DataFile = filename:join([Path, "releases", "start_erl.data"]),
+    case file:read_file(DataFile) of
+        {ok, DataBin} ->
+            [_, Version] = string:tokens(
+                             string:strip(binary_to_list(DataBin), right, $\n),
+                             " "),
+            Version;
+        {error, enoent} ->
+            ?ABORT("start_erl.data is missing", [])
+    end.
diff --git a/src/rebar_upgrade.erl b/src/rebar_upgrade.erl
index 3a38a08..6cf3958 100644
--- a/src/rebar_upgrade.erl
+++ b/src/rebar_upgrade.erl
@@ -52,9 +52,10 @@
     OldVerPath = filename:join([TargetParentDir, PrevRelPath]),
 
     %% Run checks to make sure that building a package is possible
-    {NewVerPath, NewName, NewVer} = run_checks(Config, OldVerPath,
-                                               ReltoolConfig),
+    {NewVerPath, NewName, NewVer, OldVer} = run_checks(Config, OldVerPath,
+                                                       ReltoolConfig),
     NameVer = NewName ++ "_" ++ NewVer,
+    OldRelName = get_old_rel_name(OldVerPath, OldVer, NewName),
 
     %% Save the code path prior to doing anything
     OrigPath = code:get_path(),
@@ -63,7 +64,7 @@
     ok = setup(OldVerPath, NewVerPath, NewName, NewVer, NameVer),
 
     %% Build the package
-    run_systools(NameVer, NewName),
+    run_systools(NameVer, OldRelName),
 
     %% Boot file changes
     {ok, _} = boot_files(TargetDir, NewVer, NewName),
@@ -122,7 +123,7 @@ run_checks(Config, OldVerPath, ReltoolConfig) ->
         rebar_utils:prop_check(Ver == NewVer,
                                "Reltool and .rel versions do not match~n", []),
 
-    {NewVerPath, NewName, NewVer}.
+    {NewVerPath, NewName, NewVer, OldVer}.
 
 setup(OldVerPath, NewVerPath, NewName, NewVer, NameVer) ->
     Src = filename:join([NewVerPath, "releases",
@@ -139,9 +140,9 @@ setup(OldVerPath, NewVerPath, NewName, NewVer, NameVer) ->
                                                          "lib", "*", "ebin"]))
                         ])).
 
-run_systools(NewVer, Name) ->
+run_systools(NewVer, OldRelName) ->
     Opts = [silent],
-    NameList = [Name],
+    NameList = [OldRelName],
     case systools:make_relup(NewVer, NameList, NameList, Opts) of
         {error, _, Msg} ->
             ?ABORT("Systools [systools:make_relup/4] aborted with: ~p~n",
@@ -264,3 +265,7 @@ file_info(Path) ->
         Error ->
             Error
     end.
+
+get_old_rel_name(OldVerPath, OldVer, Name) ->
+    OldRelFile = rebar_rel_utils:get_rel_file_path(Name, OldVerPath, OldVer),
+    filename:basename(OldRelFile, ".rel").
diff --git a/test/upgrade_project/README.md b/test/upgrade_project/README.md
index 8df5383..a644b21 100644
--- a/test/upgrade_project/README.md
+++ b/test/upgrade_project/README.md
@@ -38,3 +38,8 @@
 
     erl> release_handler:which_releases().
     erl> dummy_server:get_state().
+
+#### Building version 0.3
+    rm -r rel/dummy
+
+    # Now repeat steps in 'Building version 0.2' and 'Deploying with release_handler'