[logger] Add better control of file modes in logger_std_h

OTP-15602

It is allowed to set file modes for the handler to use when opening
its log file. The given modes were earlier accepted without any
checks, which could make the handler behave unexpectedly. This commit
makes sure that

* if none of write, append or exclusive is given, then append is added
* if raw is not given, it is added
* if delayed_write or {delayed_write,_,_} is not given, then
  delayed_write is added

2 files changed, 20 insertions, 14 deletions

diff --git a/lib/kernel/test/logger_SUITE.erl b/lib/kernel/test/logger_SUITE.erl
index 2dad651f9c..ce0c2efa10 100644
--- a/lib/kernel/test/logger_SUITE.erl
+++ b/lib/kernel/test/logger_SUITE.erl
@@ -1047,8 +1047,9 @@ kernel_config(Config) ->
     ok = rpc:call(Node,application,unset_env,[kernel,logger]),
     ok = rpc:call(Node,logger,internal_init_logger,[]),
     ok = rpc:call(Node,logger,add_handlers,[kernel]),
+    DefModes = [raw,append,delayed_write],
     #{primary:=#{filter_default:=log,filters:=[]},
-      handlers:=[#{id:=default,filters:=DF,config:=#{type:={file,F}}}],
+      handlers:=[#{id:=default,filters:=DF,config:=#{type:={file,F,DefModes}}}],
       module_levels:=[]} = rpc:call(Node,logger,get_config,[]),
 
     %% Same, but using 'logger' parameter instead of 'error_logger'
@@ -1060,26 +1061,26 @@ kernel_config(Config) ->
     ok = rpc:call(Node,logger,internal_init_logger,[]),
     ok = rpc:call(Node,logger,add_handlers,[kernel]),
     #{primary:=#{filter_default:=log,filters:=[]},
-      handlers:=[#{id:=default,filters:=DF,config:=#{type:={file,F}}}],
+      handlers:=[#{id:=default,filters:=DF,config:=#{type:={file,F,DefModes}}}],
       module_levels:=[]} = rpc:call(Node,logger,get_config,[]),
 
     %% Same, but with type={file,File,Modes}
     ok = rpc:call(Node,logger,remove_handler,[default]),% so it can be added again
     ok = rpc:call(Node,application,unset_env,[kernel,error_logger]),
-    M = [raw,write,delayed_write],
+    M = [raw,write],
     ok = rpc:call(Node,application,set_env,[kernel,logger,
                                             [{handler,default,logger_std_h,
                                               #{config=>#{type=>{file,F,M}}}}]]),
     ok = rpc:call(Node,logger,internal_init_logger,[]),
     ok = rpc:call(Node,logger,add_handlers,[kernel]),
     #{primary:=#{filter_default:=log,filters:=[]},
-      handlers:=[#{id:=default,filters:=DF,config:=#{type:={file,F,M}}}],
+      handlers:=[#{id:=default,filters:=DF,
+                   config:=#{type:={file,F,[delayed_write|M]}}}],
       module_levels:=[]} = rpc:call(Node,logger,get_config,[]),
 
     %% Same, but with disk_log handler
     ok = rpc:call(Node,logger,remove_handler,[default]),% so it can be added again
     ok = rpc:call(Node,application,unset_env,[kernel,error_logger]),
-    M = [raw,write,delayed_write],
     ok = rpc:call(Node,application,set_env,[kernel,logger,
                                             [{handler,default,logger_disk_log_h,
                                               #{config=>#{file=>F}}}]]),
diff --git a/lib/kernel/test/logger_std_h_SUITE.erl b/lib/kernel/test/logger_std_h_SUITE.erl
index ba491ac5fa..8cadb1083b 100644
--- a/lib/kernel/test/logger_std_h_SUITE.erl
+++ b/lib/kernel/test/logger_std_h_SUITE.erl
@@ -257,9 +257,10 @@ errors(Config) ->
     end,
 
     {error,
-     {handler_not_added,{open_failed,Log,_}}} =
+     {handler_not_added,
+      {invalid_config,logger_std_h,#{type:={file,Log,bad_file_opt}}}}} =
         logger:add_handler(myh3,logger_std_h,
-                           #{config=>#{type=>{file,Log,[bad_file_opt]}}}),
+                           #{config=>#{type=>{file,Log,bad_file_opt}}}),
 
     ok = logger:notice(?msg).
 
@@ -607,11 +608,14 @@ reconfig(cleanup, _Config) ->
 file_opts(Config) ->
     Dir = ?config(priv_dir,Config),
     Log = filename:join(Dir, lists:concat([?FUNCTION_NAME,".log"])),
-    BadFileOpts = [raw],
-    BadType = {file,Log,BadFileOpts},
-    {error,{handler_not_added,{open_failed,Log,enoent}}} =
-        logger:add_handler(?MODULE, logger_std_h,
-                           #{config => #{type => BadType}}),
+    MissingAccess = [raw],
+    Type1 = {file,Log,MissingAccess},
+    ok = logger:add_handler(?MODULE, logger_std_h,
+                            #{config => #{type => Type1}}),
+    {ok,#{config:=#{type:={file,Log,Modes1}}}} =
+        logger:get_handler_config(?MODULE),
+    [append,delayed_write,raw] = lists:sort(Modes1),
+    ok = logger:remove_handler(?MODULE),
 
     OkFileOpts = [raw,append],
     OkType = {file,Log,OkFileOpts},
@@ -622,9 +626,10 @@ file_opts(Config) ->
                               filters=>?DEFAULT_HANDLER_FILTERS([?MODULE]),
                               formatter=>{?MODULE,self()}}),
 
-    #{cb_state := #{handler_state := #{type := OkType}}} =
+    ModType = {file,Log,[delayed_write|OkFileOpts]},
+    #{cb_state := #{handler_state := #{type := ModType}}} =
         logger_olp:info(h_proc_name()),
-    {ok,#{config := #{type := OkType}}} = logger:get_handler_config(?MODULE),
+    {ok,#{config := #{type := ModType}}} = logger:get_handler_config(?MODULE),
     logger:notice(M1=?msg,?domain),
     ?check(M1),
     B1 = ?bin(M1),