we can expect non-utf8 strings in tracing messages

Author: Stephan Dilly

src/tracing.rs

@@ -76,7 +76,7 @@ extern "C" fn tracing_cb_c(level: raw::git_trace_level_t, msg: *const c_char) {
     let cb = CALLBACK.load(Ordering::SeqCst);
     panic::wrap(|| unsafe {
         let cb: TracingCb = std::mem::transmute(cb);
-        let msg = std::ffi::CStr::from_ptr(msg).to_str().unwrap();
-        cb(Binding::from_raw(level), msg);
+        let msg = std::ffi::CStr::from_ptr(msg).to_string_lossy();
+        cb(Binding::from_raw(level), msg.as_ref());
     });
 }