fix(files_sharing): Improve expiration date input change handling

If the time picker component is emitting a Date object already, then there is redundant call of `new Date(new Date())` and
therefore introduces subtle bugs, for example on chrome users could not  enter expiration date with keyboard.

- Use @update:model-value instead of @change/@input for more reliable date updates
- Ensure null and invalid dates are handled correctly in onExpirationChange
- Validate date input before updating defaultExpirationDateEnabled

Resolves : https://github.com/nextcloud/server/issues/51875

Signed-off-by: nfebe <fenn25.fn@gmail.com>

apps/files_sharing/src/components/SharingEntryLink.vue

@@ -108,7 +108,8 @@
 				type="date"
 				:min="dateTomorrow"
 				:max="maxExpirationDateEnforced"
-				@change="expirationDateChanged($event)">
+				@update:model-value="onExpirationChange"
+				@change="expirationDateChanged">
 				<template #icon>
 					<IconCalendarBlank :size="20" />
 				</template>
@@ -874,9 +875,9 @@ export default {
 		},
 
 		expirationDateChanged(event) {
-			const date = event.target.value
-			this.onExpirationChange(date)
-			this.defaultExpirationDateEnabled = !!date
+			const value = event?.target?.value
+			const isValid = !!value && !isNaN(new Date(value).getTime())
+			this.defaultExpirationDateEnabled = isValid
 		},
 
 		/**

apps/files_sharing/src/mixins/SharesMixin.js

@@ -234,8 +234,13 @@ export default {
 		 * @param {Date} date
 		 */
 		onExpirationChange(date) {
-			const formattedDate = date ? this.formatDateToString(new Date(date)) : ''
-			this.share.expireDate = formattedDate
+			if (!date) {
+				this.share.expireDate = null
+				this.$set(this.share, 'expireDate', null)
+				return
+			}
+			const parsedDate = (date instanceof Date) ? date : new Date(date)
+			this.share.expireDate = this.formatDateToString(parsedDate)
 		},
 
 		/**