Изолировать callbacks отменённой загрузки (#9)

components/form.php

@@ -223,6 +223,7 @@ $basePickerAccept = 'image/jpeg,image/png,image/gif,image/webp,image/bmp,image/a
 			xhr.withCredentials = true;
 			xhr.setRequestHeader('Accept', 'application/json');
 			xhr.onload = async () => {
+				if (attempt !== uploadAttempt || leavingUploadPage) return;
 				if (xhr.status >= 200 && xhr.status < 300) {
 					try { const result = JSON.parse(xhr.responseText); if (!result?.id) throw new Error(); await recovery.accepted({id: result.id}); redirectToTour(record); }
 					catch (_) { showUploadError(genericErrorMsg); }
@@ -230,9 +231,9 @@ $basePickerAccept = 'image/jpeg,image/png,image/gif,image/webp,image/bmp,image/a
 				}
 				showUploadError(genericErrorMsg);
 			};
-			xhr.onerror = () => showUploadError(genericErrorMsg, true);
+			xhr.onerror = () => { if (attempt === uploadAttempt && !leavingUploadPage) showUploadError(genericErrorMsg, true); };
 			xhr.send(formData);
-			} catch (_) { showUploadError(genericErrorMsg); }
+			} catch (_) { if (attempt === uploadAttempt && !leavingUploadPage) showUploadError(genericErrorMsg); }
 		}
 
 		function uploadFile(file, saved = null) {
@@ -244,9 +245,10 @@ $basePickerAccept = 'image/jpeg,image/png,image/gif,image/webp,image/bmp,image/a
 					const record = saved || await recovery.remember(new File([bytes], file.name, {type: file.type, lastModified: file.lastModified}), metadata());
 					if (attempt === uploadAttempt && !leavingUploadPage) uploadPreparedFile(file, bytes, record);
 				})
-				.catch(() => showUploadError(genericErrorMsg));
+				.catch(() => { if (attempt === uploadAttempt && !leavingUploadPage) showUploadError(genericErrorMsg); });
 		}
 		function uploadPreparedFile(file, bytes, record) {
+			const attempt = uploadAttempt;
 			const xhr = new XMLHttpRequest();
 			const formData = new FormData();
 			// Ключ загрузки: по нему сайт передаёт её в сессию посетителя (/api/images/public/claim, годен 30 мин).
@@ -268,6 +270,7 @@ $basePickerAccept = 'image/jpeg,image/png,image/gif,image/webp,image/bmp,image/a
 			};
 
 			xhr.onload = async () => {
+				if (attempt !== uploadAttempt || leavingUploadPage) return;
 				if (xhr.status >= 200 && xhr.status < 300) {
 					let response;
 					try {
@@ -297,7 +300,7 @@ $basePickerAccept = 'image/jpeg,image/png,image/gif,image/webp,image/bmp,image/a
 			};
 
 			xhr.onerror = () => {
-				showUploadError(genericErrorMsg, true);
+				if (attempt === uploadAttempt && !leavingUploadPage) showUploadError(genericErrorMsg, true);
 			};
 
 			xhr.send(formData);