Detect and very loudly warn about Return::Multilevel in exception_action()

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Schema.pm

diff --git a/lib/DBIx/Class/Schema.pm b/lib/DBIx/Class/Schema.pm
index ed219b0..84e4e37 100644 (file)
--- a/lib/DBIx/Class/Schema.pm
+++ b/lib/DBIx/Class/Schema.pm
@@ -8,7 +8,7 @@ use base 'DBIx::Class';
 use DBIx::Class::Carp;
 use Try::Tiny;
 use Scalar::Util qw/weaken blessed/;
-use DBIx::Class::_Util qw(refcount quote_sub);
+use DBIx::Class::_Util qw(refcount quote_sub is_exception scope_guard);
 use Devel::GlobalDestruction;
 use namespace::clean;
 
@@ -1055,26 +1055,67 @@ default behavior will provide a detailed stack trace.
 =cut
 
 sub throw_exception {
-  my $self = shift;
+  my ($self, @args) = @_;
 
   if (my $act = $self->exception_action) {
-    if ($act->(@_)) {
-      DBIx::Class::Exception->throw(
+
+    my $guard_disarmed;
+
+    my $guard = scope_guard {
+      return if $guard_disarmed;
+      local $SIG{__WARN__};
+      Carp::cluck("
+                    !!! DBIx::Class INTERNAL PANIC !!!
+
+The exception_action() handler installed on '$self'
+aborted the stacktrace below via a longjmp (either via Return::Multilevel or
+plain goto, or Scope::Upper or something equally nefarious). There currently
+is nothing safe DBIx::Class can do, aside from displaying this error. A future
+version ( 0.082900, when available ) will reduce the cases in which the
+handler is invoked, but this is neither a complete solution, nor can it do
+anything for other software that might be affected by a similar problem.
+
+                      !!! FIX YOUR ERROR HANDLING !!!
+
+This guard was activated beginning"
+      );
+    };
+
+    eval {
+      # if it throws - good, we'll go down to the do{} below
+      # if it doesn't - do different things depending on RV truthiness
+      if( $act->(@args) ) {
+        $args[0] = (
           "Invocation of the exception_action handler installed on $self did *not*"
         .' result in an exception. DBIx::Class is unable to function without a reliable'
         .' exception mechanism, ensure that exception_action does not hide exceptions'
-        ." (original error: $_[0])"
-      );
+        ." (original error: $args[0])"
+        );
+      }
+      else {
+        carp_unique (
+          "The exception_action handler installed on $self returned false instead"
+        .' of throwing an exception. This behavior has been deprecated, adjust your'
+        .' handler to always rethrow the supplied error'
+        );
+      }
+
+      $guard_disarmed = 1;
     }
 
-    carp_unique (
-      "The exception_action handler installed on $self returned false instead"
-    .' of throwing an exception. This behavior has been deprecated, adjust your'
-    .' handler to always rethrow the supplied error.'
-    );
+      or
+
+    do {
+      # We call this to get the necessary warnings emitted and disregard the RV
+      # as it's definitely an exception if we got as far as this do{} block
+      is_exception($@);
+
+      $guard_disarmed = 1;
+      $args[0] = $@;
+    };
   }
 
-  DBIx::Class::Exception->throw($_[0], $self->stacktrace);
+  DBIx::Class::Exception->throw($args[0], $self->stacktrace);
 }
 
 =head2 deploy