Merge pull request #1109 from nextcloud/backport/1107/stable22

[stable22] Always check for `OCA.Files` before using it (Fixes: #1106)

Author: mejo-

js/viewer-main.js

@@ -325,7 +325,7 @@ export default {
 			this.isLoaded = true
 
 			// bind Sidebar if available
-			if (OCA.Files && OCA.Files.Sidebar) {
+			if (OCA?.Files?.Sidebar) {
 				this.Sidebar = OCA.Files.Sidebar.state
 			}
 		})
@@ -364,7 +364,7 @@ export default {
 			this.cancelRequestFile()
 			this.cancelRequestFolder()
 
-			if (OCA.Files.Sidebar) {
+			if (OCA?.Files?.Sidebar) {
 				OCA.Files.Sidebar.setFullScreenMode(true)
 			}
 
@@ -647,7 +647,7 @@ export default {
 			// which then triggers cleanup.
 			OCA.Viewer.close()
 
-			if (OCA.Files.Sidebar) {
+			if (OCA?.Files?.Sidebar) {
 				OCA.Files.Sidebar.setFullScreenMode(false)
 			}
 		},
@@ -735,7 +735,7 @@ export default {
 			// Open the sidebar sharing tab
 			// TODO: also hide figure, needs a proper method for it in server Sidebar
 
-			if (OCA.Files.Sidebar) {
+			if (OCA?.Files?.Sidebar) {
 				await OCA.Files.Sidebar.open(this.currentFile.filename)
 			}
 		},