Backport 17835 to rec-5.2.x: do not index past the address for byte-aligned prefixes

[omoerbeek]

(cherry picked from commit 9e2edcf)

Backport of #17835

Short description

Checklist

I have:

• read the CONTRIBUTING.md document
• read and accepted the Developer Certificate of Origin document, including the AI Policy, and added a "Signed-off-by" to my commits
• compiled this code
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)
• checked that this code was merged to master

[coveralls]

Coverage Report for CI Build 30799697863

Coverage decreased (-0.005%) to 66.731%

Details

• Coverage decreased (-0.005%) from the base build.
• Patch coverage: 22 of 22 lines across 3 files are fully covered (100%).
• 56 coverage regressions across 11 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

56 previously-covered lines in 11 files lost coverage.

Top 10 Files by Coverage Loss	Lines Losing Coverage	Coverage
pdns/recursordist/rec-tcp.cc	10	68.22%
pdns/recursordist/syncres.cc	10	79.86%
pdns/recursordist/ext/luawrapper/include/LuaContext.hpp	8	14.15%
pdns/recursordist/rec-tcpout.cc	6	50.79%
pdns/recursordist/test-syncres_cc1.cc	6	89.74%
pdns/recursordist/pdns_recursor.cc	5	73.63%
pdns/misc.cc	3	39.93%
pdns/recursordist/test-syncres_cc2.cc	3	88.91%
pdns/iputils.hh	2	68.63%
pdns/recursordist/lwres.cc	2	70.25%

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Coverage Stats

Relevant Lines:	78121
Covered Lines:	58820
Line Coverage:	75.29%
Relevant Branches:	36012
Covered Branches:	17342
Branch Coverage:	48.16%
Branches in Coverage %:	Yes
Coverage Strength:	3668881.07 hits per line

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💛 - Coveralls