repl: backslash bug fix

thefourtheye · rvagg · commit cb971cc97d21 · 2015-09-23T08:39:33.000+10:00
The actual problem was with the line parsing logic for string literals. When we use backslash in the string literals, it used to remember the `\` as the previous character even after we parsed the character next to it. This leads to REPL thinking that the end of string literals is not reached. This patch replaces the previous character with `null`, so that it will properly skip the character next to it. Previous Discussion: #2952 Fixes: #2749 PR-URL: #2968 Reviewed-By: Roman Reiss <me@silverwind.io>
diff --git a/lib/repl.js b/lib/repl.js
@@ -288,8 +288,9 @@ function REPLServer(prompt,
 
     for (var i = 0; i < line.length; i += 1) {
       if (previous === '\\') {
-        // if it is a valid escaping, then skip processing
-        previous = current;
+        // if it is a valid escaping, then skip processing and the previous
+        // character doesn't matter anymore.
+        previous = null;
         continue;
       }
 
diff --git a/test/parallel/test-repl.js b/test/parallel/test-repl.js
@@ -242,6 +242,13 @@ function error_test() {
             'RegExp.$6\nRegExp.$7\nRegExp.$8\nRegExp.$9\n',
       expect: ['\'1\'\n', '\'2\'\n', '\'3\'\n', '\'4\'\n', '\'5\'\n', '\'6\'\n',
                '\'7\'\n', '\'8\'\n', '\'9\'\n'].join(`${prompt_unix}`) },
+    // regression tests for https://github.com/nodejs/node/issues/2749
+    { client: client_unix, send: 'function x() {\nreturn \'\\n\';\n }',
+      expect: prompt_multiline + prompt_multiline +
+              'undefined\n' + prompt_unix },
+    { client: client_unix, send: 'function x() {\nreturn \'\\\\\';\n }',
+      expect: prompt_multiline + prompt_multiline +
+              'undefined\n' + prompt_unix },
   ]);
 }
 
