closes #4208

public/src/modules/translator.js

@@ -164,7 +164,7 @@
 		if (!count) {
 			return callback(text);
 		}
-		
+
 		if (S === null) { // browser environment and S not yet initialized
 			// we need to wait for async require call
 			stringDefer.then(function () { translateKeys(keys, text, language, callback); });
@@ -205,6 +205,10 @@
 		if (value) {
 			var variable;
 			for (var i = 1, ii = variables.length; i < ii; i++) {
+
+				// see https://github.com/NodeBB/NodeBB/issues/1951
+				variables[i] = variables[i].replace(/&#37;/g, '%').replace(/&#44;/g, ',');
+
 				variable = S(variables[i]).chompRight(']]').collapseWhitespace().escapeHTML().s;
 				value = value.replace('%' + i, variable);
 			}

tests/translator.js

@@ -85,5 +85,15 @@ describe('Translator', function(){
 			});
 		});
 
+		it('should properly escape % and ,', function(done) {
+			var title = 'Test 1, 2, 3 % salmon';
+			title = title.replace(/%/g, '%').replace(/,/g, ',');
+			var key = "[[topic:composer.replying_to, " + title + "]]";
+			translator.translate(key, function(translated) {
+				assert.strictEqual(translated, 'Replying to Test 1, 2, 3 % salmon');
+				done();
+			});
+		});
+
 	});
 });