fix(spec): use saturating_sub in snapshot summary to prevent overflow panic#2144
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drbothen wants to merge 1 commit intoapache:mainfrom
Open
fix(spec): use saturating_sub in snapshot summary to prevent overflow panic#2144drbothen wants to merge 1 commit intoapache:mainfrom
drbothen wants to merge 1 commit intoapache:mainfrom
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Which issue does this PR close?
N/A — standalone bug fix.
What changes are included in this PR?
The
update_totalsfunction insnapshot_summary.rsperformsnew_total -= valueon au64. Whenremoved > previous_total + added(which can happen if metadata summaries are inconsistent or after certain compaction flows), this causes a subtraction overflow panic in debug mode and wraps to a massive number in release mode.This PR replaces the subtraction with
saturating_sub, clamping the result to 0 instead.Are these changes tested?
Yes — unit test
test_update_totals_saturating_sub_no_paniccovers the overflow scenario (removed=15, previous_total=10, added=1).