A retry to upstream DNS servers triggered by the following conditions
1) A query asking for the same data as a previous query which has not yet been answered.
2) The second query arrives more than two seconds after the first.
3) Either the source of the second query or the id field differs from the first.
fails to set the case of the retry to the same pattern as the first attempt.
However dnsmasq expects the reply from upstream to have the case
pattern of the first attempt.
If the answer to the retry arrives before the answer to the first
query, dnsmasq will notice the case mismatch, log an error, and
ignore the answer.
The worst case scenario would be the first upstream query or reply is
lost and there would follow a short period where all queries for that
particular domain would fail.
This is a 2.91 development issue, it doesn't apply to previous stable releases.
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