3 files changed, 14 insertions, 6 deletions
diff --git a/lib/output.js b/lib/output.js
index f5ca0261..907818e0 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -88,7 +88,8 @@ function OutputStream(options) {
 
     function make_string(str, quote) {
         var dq = 0, sq = 0;
-        str = str.replace(/[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff]/g, function(s){
+        str = str.replace(/[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff]/g,
+          function(s, i){
             switch (s) {
               case '"': ++dq; return '"';
               case "'": ++sq; return "'";
@@ -101,8 +102,9 @@ function OutputStream(options) {
               case "\x0B": return options.screw_ie8 ? "\\v" : "\\x0B";
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
-              case "\0": return "\\x00";
               case "\ufeff": return "\\ufeff";
+              case "\0":
+                  return /[0-7]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
             }
             return s;
         });
diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 5c6b3b8e..7686ac3f 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -6,12 +6,13 @@ ascii_only_true: {
     }
     input: {
         function f() {
-            return "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
+            return "\x000\x001\x007\x008\x00" +
+                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
                    "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x00\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\x0B\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\x0B\\f\\r\\x0e\\x0f"+"\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f"+\' !"# ... }~\\x7f\\x80\\x81 ... \\xfe\\xff\\u0fff\\uffff\'}'
 }
 
 ascii_only_false: {
@@ -22,11 +23,12 @@ ascii_only_false: {
     }
     input: {
         function f() {
-            return "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
+            return "\x000\x001\x007\x008\x00" +
+                   "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" +
                    "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" +
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x00\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\x0B\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\x0B\\f\\r\x0e\x0f"+"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"+\' !"# ... }~\x7f\x80\x81 ... \xfe\xff\u0fff\uffff\'}'
 }
 
diff --git a/test/compress/concat-strings.js b/test/compress/concat-strings.js
index 79192987..50eef8b8 100644
--- a/test/compress/concat-strings.js
+++ b/test/compress/concat-strings.js
@@ -11,6 +11,9 @@ concat_1: {
         var d = 1 + x() + 2 + 3 + "boo";
 
         var e = 1 + x() + 2 + "X" + 3 + "boo";
+
+        // be careful with concatentation with "\0" with octal-looking strings.
+        var f = "\0" + 360 + "\0" + 8 + "\0";
     }
     expect: {
         var a = "foobar" + x() + "moofoo" + y() + "xyz" + q();
@@ -18,5 +21,6 @@ concat_1: {
         var c = 1 + x() + 2 + "boo";
         var d = 1 + x() + 2 + 3 + "boo";
         var e = 1 + x() + 2 + "X3boo";
+        var f = "\x00360\08\0";
     }
 }