Fail sasl startup if some, but not all, environment variables related to log_mf_h are given

The sasl application starts and adds log_mf_h handler if all three
environment variables are given and valid. If any of the variables are
invalid, sasl startup will crash.

Earlier, if one or two of the variables were missing sasl would
successfully start but silently skip adding log_mf_h. This commit
changes this behaviour so that sasl startup will crash if some
variables are given and some are not.

2 files changed, 22 insertions, 6 deletions

diff --git a/lib/sasl/doc/src/sasl_app.xml b/lib/sasl/doc/src/sasl_app.xml
index a7fecfc440..446baccb08 100644
--- a/lib/sasl/doc/src/sasl_app.xml
+++ b/lib/sasl/doc/src/sasl_app.xml
@@ -4,7 +4,7 @@
 <appref>
   <header>
     <copyright>
-      <year>1996</year><year>2009</year>
+      <year>1996</year><year>2011</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -67,6 +67,11 @@
         <p>This error logger writes <em>all</em> events sent to
           the error logger to disk. It installs the <c>log_mf_h</c>
           event handler in the <c>error_logger</c> process.</p>
+        <p>To activate this event handler, the following three sasl
+          configuration parameters must be set:
+          <c>error_logger_mf_dir</c>, <c>error_logger_mf_maxbytes</c>
+          and <c>error_logger_mf_maxfiles</c>. See below for more
+          information about the configuration parameters.</p>
       </item>
     </taglist>
   </section>
diff --git a/lib/sasl/src/sasl.erl b/lib/sasl/src/sasl.erl
index d1babaffff..aed5f0da1f 100644
--- a/lib/sasl/src/sasl.erl
+++ b/lib/sasl/src/sasl.erl
@@ -81,27 +81,38 @@ get_mf() ->
     Dir = get_mf_dir(),
     MaxB = get_mf_maxb(),
     MaxF = get_mf_maxf(),
-    {Dir, MaxB, MaxF}.
+    case {Dir, MaxB, MaxF} of
+	{undefined,undefined,undefined} = R ->
+	    R;
+	{undefined,_,_} ->
+	    exit({missing_config, {sasl, error_logger_mf_dir}});
+	{_,undefined,_} ->
+	    exit({missing_config, {sasl, error_logger_mf_maxbytes}});
+	{_,_,undefined} ->
+	    exit({missing_config, {sasl, error_logger_mf_maxfiles}});
+	R ->
+	    R
+    end.
 
 get_mf_dir() ->
     case application:get_env(sasl, error_logger_mf_dir) of
-	{ok, false} -> throw(undefined);
+	{ok, false} -> undefined;
 	{ok, Dir} when is_list(Dir) -> Dir;
-	undefined -> throw(undefined);
+	undefined -> undefined;
 	{ok, Bad} -> exit({bad_config, {sasl, {error_logger_mf_dir, Bad}}})
     end.
 
 get_mf_maxb() ->
     case application:get_env(sasl, error_logger_mf_maxbytes) of
 	{ok, MaxB} when is_integer(MaxB) -> MaxB;
-	undefined -> throw(undefined);
+	undefined -> undefined;
 	{ok, Bad} -> exit({bad_config, {sasl, {error_logger_mf_maxbytes, Bad}}})
     end.
 
 get_mf_maxf() ->
     case application:get_env(sasl, error_logger_mf_maxfiles) of
 	{ok, MaxF} when is_integer(MaxF), MaxF > 0, MaxF < 256 -> MaxF;
-	undefined -> throw(undefined);
+	undefined -> undefined;
 	{ok, Bad} -> exit({bad_config, {sasl, {error_logger_mf_maxfiles, Bad}}})
     end.