fixed a bug in keyboard.js...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>

ui/TODO.otl

@@ -213,6 +213,18 @@ Roadmap
 			[_] caching config
 		[_] BUG: BASE_URL seems to gain a new trailing '/' on each save...
 		| low priority as this does not affect anything...
+		[X] BUG: keyboard.js, some combinations resolve problems...
+		| in current help shows E, F4, alt-F4 as "Open image in ..."
+		| 	- E and F4 work OK
+		| 	- alt-F4 both close the viewer (default) and open an image.
+		|
+		| Example:
+		| 	E: doc('Open image in external software', openImage),
+		|	F4: {
+		|			default: 'E',
+		|			alt: doc('Close viewer'),
+		|		},
+		|
 		[X] reverse ribbons...
 		[X] slideshow mode...
 		[X] default STUB image...

ui/lib/keyboard.js

@@ -213,8 +213,12 @@ function getKeyHandlers(key, modifiers, keybindings, modes, shifted_keys){
 				if(modifiers == '?'){
 					break
 				}
-				if(typeof(handler[modifiers]) == typeof('str')){
-					handler = handler[modifiers]
+				if(modifiers in handler){
+					if(typeof(handler[modifiers]) == typeof('str')){
+						handler = handler[modifiers]
+					} else {
+						break
+					}
 				} else if(typeof(handler['default']) == typeof('str')){
 					handler = handler['default']
 				} else {