Order rule traversal in RuleMatcher matching operations by Rule index

This ordering fixes a test failure we're seeing on Alpine for the
signatures/tcp-end-of-match btest, since discrepancies in rule match traversal
could lead to discrepancies in corresponding event ordering. It looks safe to
rely on across platforms since the index is driven by signature load order,
which shouldn't deviate. If this somehow doesn't hold in the future, we'll only
wind up with a test failure, not incorrect match behavior.

src/RuleMatcher.cc

@@ -657,19 +657,19 @@ RuleMatcher::MIME_Matches* RuleMatcher::Match(RuleFileMagicState* state, const u
     }
 
     // Find rules for which patterns have matched.
-    set<Rule*> rule_matches;
+    map<decltype(Rule::idx), Rule*> rule_matches;
 
     for ( AcceptingMatchSet::const_iterator it = accepted_matches.begin(); it != accepted_matches.end(); ++it ) {
         auto [aidx, mpos] = *it;
 
         Rule* r = Rule::rule_table[aidx - 1];
 
         if ( AllRulePatternsMatched(r, mpos, accepted_matches) )
-            rule_matches.insert(r);
+            rule_matches[r->Index()] = r;
     }
 
-    for ( set<Rule*>::const_iterator it = rule_matches.begin(); it != rule_matches.end(); ++it ) {
-        Rule* r = *it;
+    for ( const auto& entry : rule_matches ) {
+        Rule* r = entry.second;
 
         for ( const auto& action : r->actions ) {
             const RuleActionMIME* ram = dynamic_cast<const RuleActionMIME*>(action);
@@ -841,7 +841,7 @@ void RuleMatcher::Match(RuleEndpointState* state, Rule::PatternType type, const
     // matched patterns per connection (which is a plausible assumption).
 
     // Find rules for which patterns have matched.
-    set<pair<Rule*, MatchPos>> rule_matches;
+    map<decltype(Rule::idx), std::pair<Rule*, MatchPos>> rule_matches;
 
     for ( AcceptingMatchSet::const_iterator it = accepted_matches.begin(); it != accepted_matches.end(); ++it ) {
         AcceptIdx aidx = it->first;
@@ -850,13 +850,12 @@ void RuleMatcher::Match(RuleEndpointState* state, Rule::PatternType type, const
         Rule* r = Rule::rule_table[aidx - 1];
 
         if ( AllRulePatternsMatched(r, mpos, accepted_matches) )
-            rule_matches.insert(make_pair(r, mpos));
+            rule_matches[r->Index()] = make_pair(r, mpos);
     }
 
     // Check which of the matching rules really belong to any of our nodes.
-
-    for ( set<pair<Rule*, MatchPos>>::const_iterator it = rule_matches.begin(); it != rule_matches.end(); ++it ) {
-        auto [r, match_end_pos] = *it;
+    for ( const auto& entry : rule_matches ) {
+        auto [r, match_end_pos] = entry.second;
 
         DBG_LOG(DBG_RULES, "Accepted rule: %s", r->id);