o/fdestate/backend: address review comment

ZeyadYasser · ZeyadYasser · commit 9fee2b56a7aa · 2026-07-24T11:40:39.000+03:00
Signed-off-by: Zeyad Gouda &lt;zeyad.gouda@canonical.com&gt;
diff --git a/overlord/fdestate/backend/secret_state.go b/overlord/fdestate/backend/secret_state.go
@@ -264,7 +264,12 @@ func (s *secretState) Set(key string, value any) error {
 }
 
 func (s *secretState) capacity() uint64 {
-	return uint64(len(s.mmap)) - secretStateHeaderSize
+	l := uint64(len(s.mmap))
+	if l >= secretStateHeaderSize {
+		return l - secretStateHeaderSize
+	}
+	// unlikely
+	return 0
 }
 
 func (s *secretState) Close() error {

Original file line number	Diff line number	Diff line change
`@@ -264,7 +264,12 @@ func (s *secretState) Set(key string, value any) error {`
`264`	`264`	`}`
`265`	`265`
`266`	`266`	`func (s *secretState) capacity() uint64 {`
`267`		`- return uint64(len(s.mmap)) - secretStateHeaderSize`
	`267`	`+ l := uint64(len(s.mmap))`
	`268`	`+ if l >= secretStateHeaderSize {`
	`269`	`+ return l - secretStateHeaderSize`
	`270`	`+ }`
	`271`	`+ // unlikely`
	`272`	`+ return 0`
`268`	`273`	`}`
`269`	`274`
`270`	`275`	`func (s *secretState) Close() error {`