config: NoRulesVersion for initial comparisons

Change the rule version string for empty or no rules from the wayward
"N/A" string to an empty string.

Doing so lets comparisons with an empty rule version evaluate to true,
which conveniently reduces the amount of rule exchanges between a source
and this daemon on a clean setup.

In addition, explicitly set the version to NoRulesVersion. This was also
done in Listener.writeSourceRulesInfo, even if this now has no real
effect. However, before this method returned an empty string version,
while the rule comparison expected "N/A", resulting in rejected
submissions.

Author: oxzi

internal/config/runtime.go

@@ -164,11 +164,15 @@ func (r *RuntimeConfig) GetRuleEscalation(escalationID int64) *rule.Escalation {
 	return nil
 }
 
-const MissingRuleVersion = "N/A"
+// NoRulesVersion is a source.RulesInfo version implying that no rules are available for this source.
+//
+// Setting this to the empty string lets comparisons with an empty rule version evaluate to true, which conveniently
+// reduces the amount of rule exchanges between a source and this daemon on a clean setup.
+const NoRulesVersion = ""
 
 // GetRulesVersionFor retrieves the version of the rules for a specific source.
 //
-// If either no rules or no rule for this source exist, MissingRuleVersion is returned.
+// If either no rules or no rule for this source exist, NoRulesVersion is returned.
 //
 // May not be called while holding the write lock on the RuntimeConfig.
 func (r *RuntimeConfig) GetRulesVersionFor(srcId int64) string {
@@ -181,7 +185,7 @@ func (r *RuntimeConfig) GetRulesVersionFor(srcId int64) string {
 		}
 	}
 
-	return MissingRuleVersion
+	return NoRulesVersion
 }
 
 // GetContact returns *recipient.Contact by the given username (case-insensitive).

internal/listener/listener.go

@@ -306,7 +306,9 @@ func (l *Listener) DumpRules(w http.ResponseWriter, r *http.Request) {
 //
 // Internally, it converts the data to [baseSource.RulesInfo], being serialized JSON-encoded.
 func (l *Listener) writeSourceRulesInfo(w http.ResponseWriter, source *config.Source) {
-	var rulesInfo baseSource.RulesInfo
+	rulesInfo := baseSource.RulesInfo{
+		Version: config.NoRulesVersion,
+	}
 
 	func() { // Use a function to ensure that the RLock and RUnlock are called before writing the response.
 		l.runtimeConfig.RLock()