Improve error messages

Commit 52749df added more information to error messages to aid
debugging, but most plugin follow-up questions are code references, not
method names, and they would result in an ugly CODE(0x...) in the error
message.

This change adds the fully qualified name of plugin methods. Not sure if
I like that, I might drop the RevBank::Plugin:: prefix at some point.

revbank

@@ -6,6 +6,7 @@ use experimental 'isa';         # stable since v5.36
 use experimental 'signatures';  # stable since v5.36
 
 use List::Util qw(uniq);
+use Sub::Util qw(subname);
 use POSIX qw(ttyname);
 
 use FindBin qw($RealBin);
@@ -167,6 +168,11 @@ OUTER: for (;;) {
                     "unexpected trailing input (use ';' to separate transactions)."
                 );
 
+                my $coderef = ref($method) ? $method : $plugin->can($method);
+                my ($mname) = $coderef
+                    ? (subname($coderef) eq "__ANON__" ? "" : subname($coderef) . ": ")
+                    : (ref($method) ? "" : "$method: ");
+
                 my ($rv, @rvargs) =
 
                     ($word =~ /[^\x20-\x7f]/ and $method eq 'command' || !$plugin->AllChars($method))
@@ -183,11 +189,12 @@ OUTER: for (;;) {
                     $retry = $@->reason;
                     redo OUTER;
                 } elsif ($@) {
-                    call_hooks "plugin_fail", $plugin->id, "$method: $@";
+                    call_hooks "plugin_fail", $plugin->id, "$mname$@";
                     abort;
                 }
+
                 if (not defined $rv) {
-                    call_hooks "plugin_fail", $plugin->id, "$method: No return code";
+                    call_hooks "plugin_fail", $plugin->id, $mname . "No return code";
                     abort;
                 }
                 if (not ref $rv) {
@@ -204,8 +211,10 @@ OUTER: for (;;) {
                     $prompt = $rv;
                     @plugins = $plugin;
                     ($method) = @rvargs;
-                    call_hooks "plugin_fail", $plugin->id, "$method: No method supplied"
-                        if not ref $method;
+                    if (not ref $method) {
+                        call_hooks "plugin_fail", $plugin->id, $mname . "No method supplied";
+                        abort;
+                    }
 
                     next WORD;
                 }
@@ -247,11 +256,11 @@ OUTER: for (;;) {
                 }
                 if ($rv == NEXT) {
                     next PLUGIN if $method eq 'command';
-                    call_hooks "plugin_fail", $plugin->id, "$method: "
+                    call_hooks "plugin_fail", $plugin->id, $mname
                         . "Only 'command' should ever return NEXT.";
                     abort;
                 }
-                call_hooks "plugin_fail", $plugin->id, "$method: Invalid return value";
+                call_hooks "plugin_fail", $plugin->id, $mname . "Invalid return value";
                 abort;
             }
             call_hooks "invalid_input", $cart, $origword, $word, \@allwords;