From beef46f120a8a789aef2fe888e91f92e93c44f62 Mon Sep 17 00:00:00 2001
From: Pragmatic Software <pragma78@gmail.com>
Date: Thu, 21 May 2020 19:23:30 -0700
Subject: [PATCH] Variables such as $0 can now be escaped, e.g. in `factset`,
 etc

---
 PBot/Commands.pm |  1 -
 PBot/Factoids.pm | 28 ++++++++++++++--------------
 PBot/Modules.pm  | 12 ++++++++----
 3 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/PBot/Commands.pm b/PBot/Commands.pm
index 8b31d7f7..0e6c9fd7 100644
--- a/PBot/Commands.pm
+++ b/PBot/Commands.pm
@@ -234,7 +234,6 @@ sub interpreter {
 
             $context->{action} = $context->{arguments};
             $context->{arguments} = $self->{pbot}->{factoids}->expand_factoid_vars($context);
-            $context->{arguments} = $self->{pbot}->{factoids}->expand_special_vars($context->{from}, $context->{nick}, $context->{keyword}, $context->{arguments});
             delete $context->{action};
 
             $context->{no_nickoverride} = 1;
diff --git a/PBot/Factoids.pm b/PBot/Factoids.pm
index 4ff38aae..c6957369 100644
--- a/PBot/Factoids.pm
+++ b/PBot/Factoids.pm
@@ -436,16 +436,16 @@ sub escape_json {
 sub expand_special_vars {
     my ($self, $from, $nick, $root_keyword, $action) = @_;
 
-    $action =~ s/\$nick:json|\$\{nick:json\}/$self->escape_json($nick)/ge;
-    $action =~ s/\$channel:json|\$\{channel:json\}/$self->escape_json($from)/ge;
+    $action =~ s/(?<!\\)\$nick:json|(?<!\\)\$\{nick:json\}/$self->escape_json($nick)/ge;
+    $action =~ s/(?<!\\)\$channel:json|(?<!\\)\$\{channel:json\}/$self->escape_json($from)/ge;
     $action =~
-      s/\$randomnick:json|\$\{randomnick:json\}/my $random = $self->{pbot}->{nicklist}->random_nick($from); $random ? $self->escape_json($random) : $self->escape_json($nick)/ge;
-    $action =~ s/\$0:json|\$\{0:json\}/$self->escape_json($root_keyword)/ge;
+      s/(?<!\\)\$randomnick:json|(?<!\\)\$\{randomnick:json\}/my $random = $self->{pbot}->{nicklist}->random_nick($from); $random ? $self->escape_json($random) : $self->escape_json($nick)/ge;
+    $action =~ s/(?<!\\)\$0:json|(?<!\\)\$\{0:json\}/$self->escape_json($root_keyword)/ge;
 
-    $action =~ s/\$nick|\$\{nick\}/$nick/g;
-    $action =~ s/\$channel|\$\{channel\}/$from/g;
-    $action =~ s/\$randomnick|\$\{randomnick\}/my $random = $self->{pbot}->{nicklist}->random_nick($from); $random ? $random : $nick/ge;
-    $action =~ s/\$0\b|\$\{0\}\b/$root_keyword/g;
+    $action =~ s/(?<!\\)\$nick|(?<!\\)\$\{nick\}/$nick/g;
+    $action =~ s/(?<!\\)\$channel|(?<!\\)\$\{channel\}/$from/g;
+    $action =~ s/(?<!\\)\$randomnick|(?<!\\)\$\{randomnick\}/my $random = $self->{pbot}->{nicklist}->random_nick($from); $random ? $random : $nick/ge;
+    $action =~ s/(?<!\\)\$0\b|(?<!\\)\$\{0\}\b/$root_keyword/g;
 
     return validate_string($action, $self->{pbot}->{registry}->get_value('factoids', 'max_content_length'));
 }
@@ -475,7 +475,7 @@ sub expand_factoid_vars {
         my $offset     = 0;
         my $matches    = 0;
         my $expansions = 0;
-        $action =~ s/\$0/$root_keyword/g;
+        $action =~ s/(?<!\\)\$0/$root_keyword/g;
         my $const_action = $action;
 
         $self->{pbot}->{logger}->log("action: $const_action\n") if $debug;
@@ -609,10 +609,10 @@ sub expand_factoid_vars {
         last if $matches == 0 or $expansions == 0;
     }
 
-    $action =~ s/\\\$/\$/g;
-
     unless (@exclude) { $action = $self->expand_special_vars($from, $nick, $root_keyword, $action); }
 
+    $action =~ s/\\\$/\$/g;
+
     return validate_string($action, $self->{pbot}->{registry}->get_value('factoids', 'max_content_length'));
 }
 
@@ -897,7 +897,7 @@ sub interpreter {
     if ($self->{factoids}->exists($channel, $keyword, 'usage') and not length $context->{arguments} and $self->{factoids}->get_data($channel, $keyword, 'requires_arguments')) {
         $context->{alldone} = 1;
         my $usage = $self->{factoids}->get_data($channel, $keyword, 'usage');
-        $usage =~ s/\$0|\$\{0\}/$trigger_name/g;
+        $usage =~ s/(?<!\\)\$0|(?<!\\)\$\{0\}/$trigger_name/g;
         return $usage;
     }
 
@@ -913,7 +913,7 @@ sub interpreter {
         if ($self->{factoids}->exists($channel, $keyword, 'usage') and not length $context->{arguments}) {
             $context->{alldone} = 1;
             my $usage = $self->{factoids}->get_data($channel, $keyword, 'usage');
-            $usage =~ s/\$0|\$\{0\}/$trigger_name/g;
+            $usage =~ s/(?<!\\)\$0|(?<!\\)\$\{0\}/$trigger_name/g;
             return $usage;
         }
 
@@ -992,7 +992,7 @@ sub handle_action {
         # no arguments supplied, replace $args with $nick/$tonick, etc
         if ($self->{factoids}->exists($channel, $keyword, 'usage')) {
             $action = "/say " . $self->{factoids}->get_data($channel, $keyword, 'usage');
-            $action =~ s/\$0|\$\{0\}/$trigger_name/g;
+            $action =~ s/(?<!\\)\$0|(?<!\\)\$\{0\}/$trigger_name/g;
             $context->{alldone} = 1;
         } else {
             if   ($self->{factoids}->get_data($channel, $keyword, 'allow_empty_args')) { $action = $self->expand_action_arguments($action, undef, ''); }
diff --git a/PBot/Modules.pm b/PBot/Modules.pm
index dfdbf63a..1f4a9c6c 100644
--- a/PBot/Modules.pm
+++ b/PBot/Modules.pm
@@ -81,10 +81,14 @@ sub launch_module {
     $context->{trigger} = $trigger;
 
     my $module = $self->{pbot}->{factoids}->{factoids}->get_data($channel, $trigger, 'action');
-    $self->{pbot}->{logger}->log("("
-          . (defined $context->{from} ? $context->{from} : "(undef)")
-          . "): $context->{nick}!$context->{user}\@$context->{host}: Executing module [$context->{command}] $module $context->{arguments}\n");
-    $context->{arguments} = $self->{pbot}->{factoids}->expand_special_vars($context->{from}, $context->{nick}, $context->{root_keyword}, $context->{arguments});
+    $self->{pbot}->{logger}->log(
+        "(" . (defined $context->{from} ? $context->{from} : "(undef)")
+        . "): $context->{nick}!$context->{user}\@$context->{host}: Executing module [$context->{command}] $module $context->{arguments}\n"
+    );
+
+    $context->{action} = $context->{arguments};
+    $context->{arguments} = $self->{pbot}->{factoids}->expand_factoid_vars($context);
+    delete $context->{action};
 
     my $module_dir = $self->{pbot}->{registry}->get_value('general', 'module_dir');
     if (not chdir $module_dir) {