[cirwin]

In the example I looked at to debug this, the sequence of events was:

1. One of our customer's javascript apps sent a truncated string to their web-server in a JSON payload. This string ended with a leading surrogate (this is another instance of V8 bug discussed in the blog post).

2. Their ruby backend exploded when they tried to use a regular expression on the string (because ruby's regexp library is strict about valid utf-8).

3. The bugsnag exception notifier copied the bytes from the incoming parameter into the JSON exception notification payload (ruby didn't notice because its string library unconditionally believes you if you tell it a string is valid utf8 — another bug :p).

[sujayakar]

ah yeah step 3 seems pretty bad -- cool that you found that bug!