fix(SharingDetailsView): Prevent illegal unselection of read permissions

With the exception of "file drop" on link shares all other shares need the read permissions at least.

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

apps/files_sharing/src/views/SharingDetailsTab.vue

@@ -150,7 +150,7 @@
 						{{ t('files_sharing', 'Custom permissions') }}
 					</NcCheckboxRadioSwitch>
 					<section v-if="setCustomPermissions" class="custom-permissions-group">
-						<NcCheckboxRadioSwitch :disabled="!allowsFileDrop && share.type === SHARE_TYPES.SHARE_TYPE_LINK"
+						<NcCheckboxRadioSwitch :disabled="!canRemoveReadPermission"
 							:checked.sync="hasRead">
 							{{ t('files_sharing', 'Read') }}
 						</NcCheckboxRadioSwitch>
@@ -534,6 +534,9 @@ export default {
 			// allowed to revoke it too (but not to grant it again).
 			return (this.fileInfo.canDownload() || this.canDownload)
 		},
+		canRemoveReadPermission() {
+			return this.allowsFileDrop && this.share.type === this.SHARE_TYPES.SHARE_TYPE_LINK
+		},
 		// if newPassword exists, but is empty, it means
 		// the user deleted the original password
 		hasUnsavedPassword() {
@@ -736,6 +739,10 @@ export default {
 					this.setCustomPermissions = true
 				}
 			}
+			// Read permission required for share creation
+			if (!this.canRemoveReadPermission) {
+				this.hasRead = true
+			}
 		},
 		handleCustomPermissions() {
 			if (!this.isNewShare && (this.hasCustomPermissions || this.share.setCustomPermissions)) {