Avoid selecting an outdated merger from cache

junegunn · junegunn · commit 90a8800bb596 · 2024-10-16T00:45:12.000+09:00
We cache a merger for partial input as well, because it is automatically invalidated as soon as the new data comes in. However, there was a race condition where a cached merger for a partial input is used even after the input stream was complete. This commit fixes the problem. Fix #4034
diff --git a/src/matcher.go b/src/matcher.go
@@ -102,7 +102,7 @@ func (m *Matcher) Loop() {
 		if !cacheCleared {
 			if count == prevCount {
 				// Look up mergerCache
-				if cached, found := m.mergerCache[patternString]; found {
+				if cached, found := m.mergerCache[patternString]; found && cached.final == request.final {
 					merger = cached
 				}
 			} else {

Original file line number	Diff line number	Diff line change
`@@ -102,7 +102,7 @@ func (m *Matcher) Loop() {`
`102`	`102`	`if !cacheCleared {`
`103`	`103`	`if count == prevCount {`
`104`	`104`	`// Look up mergerCache`
`105`		`- if cached, found := m.mergerCache[patternString]; found {`
	`105`	`+ if cached, found := m.mergerCache[patternString]; found && cached.final == request.final {`
`106`	`106`	`merger = cached`
`107`	`107`	`}`
`108`	`108`	`} else {`