Prevent duplicate payment processing

includes/abstracts/abstract-wc-stripe-payment-gateway.php

@@ -536,14 +536,16 @@ public function process_response( $response, $order ) {
 				$order->payment_complete( $response->id );
 
 				/* translators: transaction id */
-				$message = sprintf( __( 'Stripe charge complete (Charge ID: %s)', 'woocommerce-gateway-stripe' ), $response->id );
-				$order->add_order_note( $message );
+				$note = sprintf( __( 'Stripe charge complete (Charge ID: %s)', 'woocommerce-gateway-stripe' ), $response->id );
 			}
 
 			if ( 'failed' === $response->status ) {
-				$localized_message = __( 'Payment processing failed. Please retry.', 'woocommerce-gateway-stripe' );
-				$order->add_order_note( $localized_message );
-				throw new WC_Stripe_Exception( print_r( $response, true ), $localized_message );
+				$note = __( 'Payment processing failed. Please retry.', 'woocommerce-gateway-stripe' );
+				throw new WC_Stripe_Exception( print_r( $response, true ), $note );
+			}
+
+			if ( isset( $note ) && ! WC_Stripe_Helper::order_note_exists( $order, $note ) ) {
+				$order->add_order_note( $note );
 			}
 		} else {
 			$order->set_transaction_id( $response->id );

includes/class-wc-stripe-helper.php

@@ -695,4 +695,27 @@ public static function add_payment_intent_to_order( $payment_intent_id, $order )
 		$order->update_meta_data( '_stripe_intent_id', $payment_intent_id );
 		$order->save();
 	}
+
+	/**
+	 * Check if a note content does already exist in the order.
+	 *
+	 * @param WC_Order $order        The order object to add the note.
+	 * @param string   $note_content Note content.
+	 *
+	 * @return bool true if the note content exists, false otherwise.
+	 */
+	public static function order_note_exists( WC_Order $order, string $note_content ): bool {
+		// Get current notes of the order.
+		$current_notes = wc_get_order_notes(
+			[ 'order_id' => $order->get_id() ]
+		);
+
+		foreach ( $current_notes as $current_note ) {
+			if ( $current_note->content === $note_content ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
 }