only valid utf8 in logs

CHANGELOG.md

@@ -12,6 +12,7 @@
   - Fix crash when peer info has missing or unsupported node ids
   - Add 'auto' mode for detect_address_changes
   - Improved `TypedXXX` conversion traits, including to and from `Vec<u8>`
+  - Ensure utf8 replacement characters are never emitted in logs
 
 - veilid-server:
   - Use `detect_address_changes: auto` by default

veilid-core/src/logging/api_tracing_layer.rs

@@ -134,11 +134,19 @@ impl ApiTracingLayer {
                 .unwrap_or_default(),
         };
 
-        let message = format!("{} {}", origin, message).trim().to_owned();
+        // Dart can't handle the Unicode Replacement Character
+        // and it causes crashes on multiple Flutter applications
+        // see: https://gitlab.com/veilid/veilid/-/issues/473
+        // We sanitize the logs here because it is generally a good idea to
+        // ensure only valid UTF8 strings are returned to applications
+
+        let message = format!("{} {}", origin, message)
+            .trim()
+            .replace(char::REPLACEMENT_CHARACTER, "");
 
         let backtrace = if log_level <= VeilidLogLevel::Error {
             let bt = backtrace::Backtrace::new();
-            Some(format!("{:?}", bt))
+            Some(format!("{:?}", bt).replace(char::REPLACEMENT_CHARACTER, ""))
         } else {
             None
         };