fix break of in dial

Author: ndyakov

internal/pool/pool.go

@@ -319,29 +319,24 @@ func (p *ConnPool) dialConn(ctx context.Context, pooled bool) (*Conn, error) {
 	const backoffDuration = 100 * time.Millisecond
 
 	var lastErr error
-	for attempt := 0; attempt < maxRetries; attempt++ {
-		// Add backoff delay for retry attempts
-		// (not for the first attempt, do at least one)
-		if attempt > 0 {
+	shouldLoop := true
+	// when the timeout is reached, we should stop retrying
+	// but keep the lastErr to return to the caller
+	// instead of a generic context deadline exceeded error
+	for attempt := 0; (attempt < maxRetries) && shouldLoop; attempt++ {
+		netConn, err := p.cfg.Dialer(ctx)
+		if err != nil {
+			lastErr = err
+			// Add backoff delay for retry attempts
+			// (not for the first attempt, do at least one)
 			select {
 			case <-ctx.Done():
-				// we should have lastErr set, but just in case
-				if lastErr == nil {
-					lastErr = ctx.Err()
-				}
-				break
+				shouldLoop = false
 			case <-time.After(backoffDuration):
 				// Continue with retry
 			}
 		}
 
-		netConn, err := p.cfg.Dialer(ctx)
-		if err != nil {
-			lastErr = err
-			// Continue to next retry attempt
-			continue
-		}
-
 		// Success - create connection
 		cn := NewConnWithBufferSize(netConn, p.cfg.ReadBufferSize, p.cfg.WriteBufferSize)
 		cn.pooled = pooled