Simple string write

Author: gyuheon0h

datadog-crashtracker/src/runtime_callback.rs

@@ -352,14 +352,18 @@ pub(crate) unsafe fn invoke_runtime_callback_with_writer<W: std::io::Write>(
         });
     }
 
-    // Define the emit_stacktrace_string function that writes directly to the pipe
     unsafe extern "C" fn emit_stacktrace_string_collector(stacktrace_string: *const c_char) {
-        let stacktrace_string_str = std::ffi::CStr::from_ptr(stacktrace_string);
-        let stacktrace_string_str = stacktrace_string_str.to_str().unwrap();
+        if stacktrace_string.is_null() {
+            return;
+        }
+
+        let cstr = std::ffi::CStr::from_ptr(stacktrace_string);
+        let bytes = cstr.to_bytes();
+
         FRAME_WRITER.with(|writer_cell| {
             if let Some(writer_ptr) = *writer_cell.borrow() {
                 let writer = &mut *writer_ptr;
-                let _ = writer.write_all(stacktrace_string_str.as_bytes());
+                let _ = writer.write_all(bytes);
                 let _ = writer.flush();
             }
         });