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fix: remove capacity pre-allocation in mergeFetchRefs to avoid overflow (CodeQL #555) #22774

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Merged
pelikhan merged 3 commits into from
Mar 24, 2026
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fix: remove capacity pre-allocation in mergeFetchRefs to avoid overflow (CodeQL #555) #22774

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6e1d5e2
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Copilot Mar 24, 2026
b81dda8
fix: guard against integer overflow in mergeFetchRefs allocation (ale…
Copilot Mar 24, 2026
6c2f7df
fix: remove pre-allocation from mergeFetchRefs to avoid overflow
Copilot Mar 24, 2026
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2 changes: 1 addition & 1 deletion pkg/workflow/checkout_manager.go
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Original file line number Diff line number Diff line change
Expand Up @@ -597,7 +597,7 @@ func mergeSparsePatterns(existing []string, newPatterns string) []string {
// mergeFetchRefs unions two sets of fetch ref patterns preserving insertion order.
func mergeFetchRefs(existing []string, newRefs []string) []string {
seen := make(map[string]bool, len(existing))
result := make([]string, 0, len(existing)+len(newRefs))
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@pelikhan pelikhan Mar 24, 2026

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@copilot do not pre-allocate size

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Copilot AI Mar 24, 2026

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Done in 6c2f7df — replaced make([]string, 0, capacity) with make([]string, 0) and removed the math import.

result := make([]string, 0)
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Copilot AI Mar 24, 2026

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Dropping pre-allocation entirely fixes the overflow, but it also guarantees extra realloc/copy work for typical inputs. You can keep the fix and still reduce allocations by preallocating to len(existing) (safe since it doesn’t involve an addition) or by using an overflow-checked sum before setting capacity.

Suggested change
result := make([]string, 0)
result := make([]string, 0, len(existing))

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for _, r := range existing {
r = strings.TrimSpace(r)
if r != "" && !seen[r] {
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