Merge pull request #312 from Nikerabbit/consuming

Given that it's complicated for all of us in the team to test it, we'll deploy it on translatewiki.net and we'll ask the user who opened the bug to test.

src/jquery.ime.js

@@ -46,10 +46,12 @@
 		 * @param {string} input
 		 * @param {string} context
 		 * @param {boolean} altGr whether altGr key is pressed or not
-		 * @returns {string} transliterated string
+		 * @returns {object} transliteration object
+		 * @returns {bool} return.noop Whether to consider input processed or passed through.
+		 * @returns {string} return.output the transliterated input or input unmodified.
 		 */
 		transliterate: function ( input, context, altGr ) {
-			var patterns, regex, rule, replacement, i;
+			var patterns, regex, rule, replacement, i, retval;
 
 			if ( altGr ) {
 				patterns = this.inputmethod.patterns_x || [];
@@ -66,7 +68,15 @@
 			}
 
 			if ( $.isFunction( patterns ) ) {
-				return patterns.call( this, input, context );
+				// For backwards compatibility, allow the rule functions to return plain
+				// string. Determine noop by checking whether input is different from
+				// output. If the rule function returns object, just return it as-is.
+				retval = patterns.call( this, input, context );
+				if ( typeof retval === 'string' ) {
+					return { noop: input === retval, output: retval };
+				}
+
+				return retval;
 			}
 
 			for ( i = 0; i < patterns.length; i++ ) {
@@ -83,17 +93,16 @@
 					// Context test required?
 					if ( rule.length === 3 ) {
 						if ( new RegExp( rule[1] + '$' ).test( context ) ) {
-							return input.replace( regex, replacement );
+							return { noop: false, output: input.replace( regex, replacement ) };
 						}
 					} else {
-						// No context test required. Just replace.
-						return input.replace( regex, replacement );
+						return { noop: false, output: input.replace( regex, replacement ) };
 					}
 				}
 			}
 
 			// No matches, return the input
-			return input;
+			return { noop: true, output: input };
 		},
 
 		keyup: function ( e ) {
@@ -177,20 +186,20 @@
 				);
 			}
 
-			// If replacement equals to input, no replacement is made, because
-			// there's apparently nothing to do. However, there may be something
-			// to do if AltGr was pressed. For example, if a layout is built in
-			// a way that allows typing the original character instead of
-			// the replacement by pressing it with AltGr.
-			if ( !altGr && replacement === input ) {
+			// Allow rules to explicitly define whether we match something.
+			// Otherwise we cannot distinguish between no matching rule and
+			// rule that provides identical output but consumes the event
+			// to prevent normal behavior. See Udmurt layout which uses
+			// altgr rules to allow typing the original character.
+			if ( replacement.noop ) {
 				return true;
 			}
 
 			// Drop a common prefix, if any
-			divergingPos = this.firstDivergence( input, replacement );
+			divergingPos = this.firstDivergence( input, replacement.output );
 			input = input.substring( divergingPos );
-			replacement = replacement.substring( divergingPos );
-			replaceText( this.$element, replacement, startPos - input.length + 1, endPos );
+			replacement.output = replacement.output.substring( divergingPos );
+			replaceText( this.$element, replacement.output, startPos - input.length + 1, endPos );
 
 			e.stopPropagation();