tests run on OpenBSD; a tool's error message survives one large write; lock pids beyond 32 bits name no process

1 files changed, 10 insertions, 8 deletions

diff --git a/internal/extract/tools.go b/internal/extract/tools.go
index ca6a9b0..f815123 100644
--- a/internal/extract/tools.go
+++ b/internal/extract/tools.go
@@ -65,17 +65,19 @@ type boundedWriter struct {
 }
 
 func (w *boundedWriter) Write(p []byte) (int, error) {
+	if room := w.limit - w.total; room > 0 {
+		// The part of p that still fits is kept even when p overflows, so a
+		// tool that writes its whole error message in one large write still
+		// has that message's start to show.
+		w.buf.Write(p[:min(int64(len(p)), room)])
+	}
 	w.total += int64(len(p))
-	if w.total > w.limit {
-		if !w.overflowed {
-			w.overflowed = true
-			if w.onOverflow != nil {
-				w.onOverflow()
-			}
+	if w.total > w.limit && !w.overflowed {
+		w.overflowed = true
+		if w.onOverflow != nil {
+			w.onOverflow()
 		}
-		return len(p), nil
 	}
-	w.buf.Write(p)
 	return len(p), nil
 }