From 3ff660392ee7d365acb5b0de1a9969daac753f37 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Fri, 30 Sep 2016 14:13:44 +0200
Subject: [PATCH 01/13] TSII-1535: Also do not un-escape \uffff

---
 lib/output.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/output.js b/lib/output.js
index a3c6b4ab..62dbf49b 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -134,7 +134,7 @@ 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,
+        str = str.replace(/[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff\uffff]/g,
           function(s, i){
             switch (s) {
               case '"': ++dq; return '"';
@@ -149,6 +149,7 @@ function OutputStream(options) {
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
               case "\ufeff": return "\\ufeff";
+              case "\uffff": return "\\uffff";
               case "\0":
                   return /[0-7]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
             }
@@ -1282,6 +1283,7 @@ function OutputStream(options) {
             0x0d   , // \r
             0x00   , // \0
             0xfeff , // Unicode BOM
+            0xffff , // Unicode noncharacter
             0x2028 , // unicode "line separator"
             0x2029 , // unicode "paragraph separator"
         ].indexOf(code) < 0;

From 947aef405cae91e3ea49e58875576c4d0ebb5e4a Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Fri, 30 Sep 2016 14:54:35 +0200
Subject: [PATCH 02/13] Add more characters that should not be un-escaped in
 regexps.

---
 lib/output.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/output.js b/lib/output.js
index 62dbf49b..05f8b5d1 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -1282,6 +1282,7 @@ function OutputStream(options) {
             0x0a   , // \n
             0x0d   , // \r
             0x00   , // \0
+            0x1f   ,
             0xfeff , // Unicode BOM
             0xffff , // Unicode noncharacter
             0x2028 , // unicode "line separator"

From b4f8e7dc7b257da2ad1dbbc53788fabd105b6bce Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Fri, 30 Sep 2016 15:10:23 +0200
Subject: [PATCH 03/13] Add more characters that should not be un-escaped in
 regexps.

---
 lib/output.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/output.js b/lib/output.js
index 05f8b5d1..59556f5e 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -134,7 +134,7 @@ 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\uffff]/g,
+        str = str.replace(/[\\\b\f\n\r\v\t\x1f\x22\x27\u2028\u2029\0\ufeff\uffff]/g,
           function(s, i){
             switch (s) {
               case '"': ++dq; return '"';
@@ -146,6 +146,7 @@ function OutputStream(options) {
               case "\b": return "\\b";
               case "\f": return "\\f";
               case "\x0B": return options.screw_ie8 ? "\\v" : "\\x0B";
+              case "\x1f": return "\\x1f";
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
               case "\ufeff": return "\\ufeff";

From 75e5f6edf9425f52d199fb56417802239d42c7b1 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Fri, 30 Sep 2016 15:17:05 +0200
Subject: [PATCH 04/13] Add more characters that should not be un-escaped in
 regexps.

---
 lib/output.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/output.js b/lib/output.js
index 59556f5e..53afdbf9 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -134,7 +134,7 @@ function OutputStream(options) {
 
     function make_string(str, quote) {
         var dq = 0, sq = 0;
-        str = str.replace(/[\\\b\f\n\r\v\t\x1f\x22\x27\u2028\u2029\0\ufeff\uffff]/g,
+        str = str.replace(/[\\\b\f\n\r\v\t\x1f\x22\x27\u2028\u2029\0\ufeff\ufffe\uffff]/g,
           function(s, i){
             switch (s) {
               case '"': ++dq; return '"';
@@ -150,6 +150,7 @@ function OutputStream(options) {
               case "\u2028": return "\\u2028";
               case "\u2029": return "\\u2029";
               case "\ufeff": return "\\ufeff";
+              case "\ufffe": return "\\ufffe";
               case "\uffff": return "\\uffff";
               case "\0":
                   return /[0-7]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
@@ -1285,6 +1286,7 @@ function OutputStream(options) {
             0x00   , // \0
             0x1f   ,
             0xfeff , // Unicode BOM
+            0xfffe , // Unicode noncharacter
             0xffff , // Unicode noncharacter
             0x2028 , // unicode "line separator"
             0x2029 , // unicode "paragraph separator"

From 4e98b220da7e7d3ac32127a1f5d249dd1a9995dc Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Sat, 1 Oct 2016 13:29:11 +0200
Subject: [PATCH 05/13] Fix test case for added un-escaped characters

---
 test/compress/ascii.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 2232d263..2b019829 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -31,6 +31,5 @@ ascii_only_false: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\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\\v\\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\\v\\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\'}'
 }
-

From 9ba2bbed46453c2241df61f6f812685130b1d482 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Sat, 1 Oct 2016 17:50:25 +0200
Subject: [PATCH 06/13] Add \uFFFE to tests.

---
 test/compress/ascii.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 2b019829..4b629c8f 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -10,10 +10,10 @@ ascii_only_true: {
             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";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\ufffe\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\\v\\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\\ufffe\\uffff\'}'
 }
 
 ascii_only_false: {
@@ -28,8 +28,8 @@ ascii_only_false: {
             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";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\ufffe\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\\v\\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\\ufffe\\uffff\'}'
 }

From 9c6036bd71bf2c40f80c0dc3299b7205813386dc Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Tue, 4 Oct 2016 11:38:35 +0200
Subject: [PATCH 07/13] Factor out the escaping of characters that are not
 XML-safe into its own output option xml_safe

---
 lib/output.js           | 36 ++++++++++++++++++++---------
 test/compress/ascii.js  | 24 ++++++++++++++++++--
 test/compress/regexp.js | 50 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 97 insertions(+), 13 deletions(-)
 create mode 100644 test/compress/regexp.js

diff --git a/lib/output.js b/lib/output.js
index 53afdbf9..2dc0694a 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -53,6 +53,7 @@ function OutputStream(options) {
         quote_keys       : false,
         space_colon      : true,
         ascii_only       : false,
+        xml_safe         : false,
         unescape_regexps : false,
         inline_script    : false,
         width            : 80,
@@ -134,7 +135,10 @@ function OutputStream(options) {
 
     function make_string(str, quote) {
         var dq = 0, sq = 0;
-        str = str.replace(/[\\\b\f\n\r\v\t\x1f\x22\x27\u2028\u2029\0\ufeff\ufffe\uffff]/g,
+        var re = options.xml_safe ?
+            /[\x00-\x1f\x22\x27\u2028\u2029\0\ud800-\udfff\ufeff\ufffe\uffff]/g :
+            /[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff\uffff]/g;
+        str = str.replace(re,
           function(s, i){
             switch (s) {
               case '"': ++dq; return '"';
@@ -146,14 +150,10 @@ function OutputStream(options) {
               case "\b": return "\\b";
               case "\f": return "\\f";
               case "\x0B": return options.screw_ie8 ? "\\v" : "\\x0B";
-              case "\x1f": return "\\x1f";
-              case "\u2028": return "\\u2028";
-              case "\u2029": return "\\u2029";
-              case "\ufeff": return "\\ufeff";
-              case "\ufffe": return "\\ufffe";
-              case "\uffff": return "\\uffff";
               case "\0":
                   return /[0-7]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
+              default:
+                  return to_ascii(s);
             }
             return s;
         });
@@ -1262,7 +1262,22 @@ function OutputStream(options) {
         }
     });
 
-    function regexp_safe_literal(code) {
+    function regexp_safe_literal(code, xml_safe) {
+        if (xml_safe) {
+            if ([
+                // all C0 characters except tab, newline and return are invalid
+                0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                0x08, 0x0c, 0x0e, 0x0f,
+                0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+                0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+                0xfffe
+            ].indexOf(code) >= 0)
+                return false;
+            // C1 (except 0x85) and surrogate pair code points are invalid
+            if ((code >= 0x7f && code != 0x85 && code <= 0x9f)
+                    || (code >= 0xd800 && code <= 0xdfff))
+                return false;
+        }
         return [
             0x5c   , // \
             0x2f   , // /
@@ -1284,9 +1299,7 @@ function OutputStream(options) {
             0x0a   , // \n
             0x0d   , // \r
             0x00   , // \0
-            0x1f   ,
             0xfeff , // Unicode BOM
-            0xfffe , // Unicode noncharacter
             0xffff , // Unicode noncharacter
             0x2028 , // unicode "line separator"
             0x2029 , // unicode "paragraph separator"
@@ -1298,10 +1311,11 @@ function OutputStream(options) {
         if (output.option("ascii_only")) {
             str = output.to_ascii(str);
         } else if (output.option("unescape_regexps")) {
+            var xml_safe = output.option("xml_safe");
             str = str.split("\\\\").map(function(str){
                 return str.replace(/\\u[0-9a-fA-F]{4}|\\x[0-9a-fA-F]{2}/g, function(s){
                     var code = parseInt(s.substr(2), 16);
-                    return regexp_safe_literal(code) ? String.fromCharCode(code) : s;
+                    return regexp_safe_literal(code, xml_safe) ? String.fromCharCode(code) : s;
                 });
             }).join("\\\\");
         }
diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 4b629c8f..16c31d14 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -1,3 +1,22 @@
+ascii_only_false_xml_safe_false: {
+    options = {}
+    beautify = {
+        ascii_only : false,
+        xml_safe   : false,
+        screw_ie8  : true,
+        beautify   : false,
+    }
+    input: {
+        function f() {
+            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\ufffe\uffff";
+        }
+    }
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\ufffe\\uffff\'}'
+}
+
 ascii_only_true: {
     options = {}
     beautify = {
@@ -16,10 +35,11 @@ ascii_only_true: {
     expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\\ufffe\\uffff\'}'
 }
 
-ascii_only_false: {
+xml_safe_true: {
     options = {}
     beautify = {
         ascii_only : false,
+        xml_safe   : true,
         screw_ie8  : true,
         beautify   : false,
     }
@@ -31,5 +51,5 @@ ascii_only_false: {
                    "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff\ufffe\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\\ufffe\\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\\ufffe\\uffff\'}'
 }
diff --git a/test/compress/regexp.js b/test/compress/regexp.js
new file mode 100644
index 00000000..b804dccc
--- /dev/null
+++ b/test/compress/regexp.js
@@ -0,0 +1,50 @@
+regexp: {
+    options = {}
+    beautify = {
+        ascii_only       : false,
+        xml_safe         : false,
+        unescape_regexps : true,
+        screw_ie8        : true,
+        beautify         : false,
+    }
+    input: {
+        function f() {
+            return /[\x00\x0d\x1f \x61\u0fff\ud800\ufffe\uffff]/;
+        }
+    }
+    expect_exact: 'function f(){return/[\\x00\\x0d\x1f a\u0fff\ud800\ufffe\\uffff]/}'
+}
+
+regexp_ascii_only: {
+    options = {}
+    beautify = {
+        ascii_only       : true,
+        xml_safe         : false,
+        unescape_regexps : true,
+        screw_ie8        : true,
+        beautify         : false,
+    }
+    input: {
+        function f() {
+            return /[\x00\x0d\x1f \x61\u0fff\ud800\ufffe\uffff]/;
+        }
+    }
+    expect_exact: 'function f(){return/[\\x00\\x0d\\x1f \\x61\\u0fff\\ud800\\ufffe\\uffff]/}'
+}
+
+regexp_xml_safe_true: {
+    options = {}
+    beautify = {
+        ascii_only       : false,
+        xml_safe         : true,
+        unescape_regexps : true,
+        screw_ie8        : true,
+        beautify         : false,
+    }
+    input: {
+        function f() {
+            return /[\x00\x0d\x1f \x61\u0fff\ud800\ufffe\uffff]/;
+        }
+    }
+    expect_exact: 'function f(){return/[\\x00\\x0d\\x1f a\u0fff\\ud800\\ufffe\\uffff]/}'
+}

From 9c0ecd3fa1a5f511ca1cc2ad5f1f9b55503f3964 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Tue, 4 Oct 2016 17:46:21 +0200
Subject: [PATCH 08/13] Rearrange tests to increase readability of diff

---
 test/compress/ascii.js  | 38 +++++++++++++++++++-------------------
 test/compress/regexp.js |  2 +-
 2 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 16c31d14..671007bb 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -1,22 +1,3 @@
-ascii_only_false_xml_safe_false: {
-    options = {}
-    beautify = {
-        ascii_only : false,
-        xml_safe   : false,
-        screw_ie8  : true,
-        beautify   : false,
-    }
-    input: {
-        function f() {
-            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\ufffe\uffff";
-        }
-    }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\ufffe\\uffff\'}'
-}
-
 ascii_only_true: {
     options = {}
     beautify = {
@@ -35,6 +16,25 @@ ascii_only_true: {
     expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\\ufffe\\uffff\'}'
 }
 
+ascii_only_false: { // also tests xml_safe===false
+    options = {}
+    beautify = {
+        ascii_only : false,
+        xml_safe   : false,
+        screw_ie8  : true,
+        beautify   : false,
+    }
+    input: {
+        function f() {
+            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\ufffe\uffff";
+        }
+    }
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\ufffe\\uffff\'}'
+}
+
 xml_safe_true: {
     options = {}
     beautify = {
diff --git a/test/compress/regexp.js b/test/compress/regexp.js
index b804dccc..27a3c1a2 100644
--- a/test/compress/regexp.js
+++ b/test/compress/regexp.js
@@ -15,7 +15,7 @@ regexp: {
     expect_exact: 'function f(){return/[\\x00\\x0d\x1f a\u0fff\ud800\ufffe\\uffff]/}'
 }
 
-regexp_ascii_only: {
+regexp_ascii_only_true: {
     options = {}
     beautify = {
         ascii_only       : true,

From c04a343e29432d4d67031ebf832a4748c3139bbc Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Tue, 4 Oct 2016 18:27:33 +0200
Subject: [PATCH 09/13] Fully restore standard functionality; all addional
 escaping is now properly hidden behind xml_safe

---
 lib/output.js           |  5 ++---
 test/compress/ascii.js  | 10 +++++-----
 test/compress/regexp.js |  2 +-
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index 2dc0694a..764b8e36 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -137,7 +137,7 @@ function OutputStream(options) {
         var dq = 0, sq = 0;
         var re = options.xml_safe ?
             /[\x00-\x1f\x22\x27\u2028\u2029\0\ud800-\udfff\ufeff\ufffe\uffff]/g :
-            /[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff\uffff]/g;
+            /[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff]/g;
         str = str.replace(re,
           function(s, i){
             switch (s) {
@@ -1270,7 +1270,7 @@ function OutputStream(options) {
                 0x08, 0x0c, 0x0e, 0x0f,
                 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
                 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
-                0xfffe
+                0xfffe, 0xffff
             ].indexOf(code) >= 0)
                 return false;
             // C1 (except 0x85) and surrogate pair code points are invalid
@@ -1300,7 +1300,6 @@ function OutputStream(options) {
             0x0d   , // \r
             0x00   , // \0
             0xfeff , // Unicode BOM
-            0xffff , // Unicode noncharacter
             0x2028 , // unicode "line separator"
             0x2029 , // unicode "paragraph separator"
         ].indexOf(code) < 0;
diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 671007bb..7166f506 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -10,13 +10,13 @@ ascii_only_true: {
             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\ufffe\uffff";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\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\\v\\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\\ufffe\\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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: { // also tests xml_safe===false
+ascii_only_false: {
     options = {}
     beautify = {
         ascii_only : false,
@@ -29,10 +29,10 @@ ascii_only_false: { // also tests xml_safe===false
             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\ufffe\uffff";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\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\\v\\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\ufffe\\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\'}'
 }
 
 xml_safe_true: {
diff --git a/test/compress/regexp.js b/test/compress/regexp.js
index 27a3c1a2..1dc7f7e2 100644
--- a/test/compress/regexp.js
+++ b/test/compress/regexp.js
@@ -12,7 +12,7 @@ regexp: {
             return /[\x00\x0d\x1f \x61\u0fff\ud800\ufffe\uffff]/;
         }
     }
-    expect_exact: 'function f(){return/[\\x00\\x0d\x1f a\u0fff\ud800\ufffe\\uffff]/}'
+    expect_exact: 'function f(){return/[\\x00\\x0d\x1f a\u0fff\ud800\ufffe\uffff]/}'
 }
 
 regexp_ascii_only_true: {

From e1d78410c61596b1f9b3116e21b82699c85cc974 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Tue, 4 Oct 2016 18:47:29 +0200
Subject: [PATCH 10/13] Extract array of unsafe XML chars to variable

---
 lib/output.js | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index 764b8e36..ddc28820 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -1262,16 +1262,18 @@ function OutputStream(options) {
         }
     });
 
+    var xml_unsafe = [
+        // all C0 characters except tab, newline and return are invalid
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+        0x08, 0x0c, 0x0e, 0x0f,
+        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+        0xfffe, 0xffff
+    ];
+
     function regexp_safe_literal(code, xml_safe) {
         if (xml_safe) {
-            if ([
-                // all C0 characters except tab, newline and return are invalid
-                0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
-                0x08, 0x0c, 0x0e, 0x0f,
-                0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
-                0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
-                0xfffe, 0xffff
-            ].indexOf(code) >= 0)
+            if (xml_unsafe.indexOf(code) >= 0)
                 return false;
             // C1 (except 0x85) and surrogate pair code points are invalid
             if ((code >= 0x7f && code != 0x85 && code <= 0x9f)

From 41ad14e6fac98828a2c2e0cdacd364417413a193 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stefan.bethke@t-systems.com>
Date: Tue, 4 Oct 2016 18:56:08 +0200
Subject: [PATCH 11/13] Add Unicode line break, paragraph bream and byte order
 mark to tests.

---
 test/compress/ascii.js | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/test/compress/ascii.js b/test/compress/ascii.js
index 7166f506..4d0f8a21 100644
--- a/test/compress/ascii.js
+++ b/test/compress/ascii.js
@@ -10,10 +10,11 @@ ascii_only_true: {
             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";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff" +
+                   "\u2028\u2029\ufeff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\\v\\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\'+"\\u2028\\u2029\\ufeff\\uffff"}'
 }
 
 ascii_only_false: {
@@ -29,10 +30,11 @@ ascii_only_false: {
             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";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff" +
+                   "\u2028\u2029\ufeff\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\x01\x02\x03\x04\x05\x06\x07\\b\\t\\n\\v\\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\\v\\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\'+"\\u2028\\u2029\\ufeff\uffff"}'
 }
 
 xml_safe_true: {
@@ -48,8 +50,9 @@ xml_safe_true: {
             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\ufffe\uffff";
+                   "\x20\x21\x22\x23 ... \x7d\x7e\x7f\x80\x81 ... \xfe\xff\u0fff" +
+                   "\u2028\u2029\ufeff\ufffe\uffff";
         }
     }
-    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\\ufffe\\uffff\'}'
+    expect_exact: 'function f(){return"\\x000\\x001\\x007\\08\\0"+"\\0\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\b\\t\\n\\v\\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\'+"\\u2028\\u2029\\ufeff\\ufffe\\uffff"}'
 }

From 63a83a65c3e7b6ea8d1e3dd7f8594c73ebfb4c64 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stb@lassitu.de>
Date: Wed, 5 Oct 2016 16:49:53 +0200
Subject: [PATCH 12/13] Remove superflous code.

---
 lib/output.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index ddc28820..dd94fea5 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -152,10 +152,8 @@ function OutputStream(options) {
               case "\x0B": return options.screw_ie8 ? "\\v" : "\\x0B";
               case "\0":
                   return /[0-7]/.test(str.charAt(i+1)) ? "\\x00" : "\\0";
-              default:
-                  return to_ascii(s);
             }
-            return s;
+            return to_ascii(s);
         });
         function quote_single() {
             return "'" + str.replace(/\x27/g, "\\'") + "'";

From 0b6b8b3da3bd1974f26e6b65fa9bb0f3cb001200 Mon Sep 17 00:00:00 2001
From: Stefan Bethke <stb@lassitu.de>
Date: Wed, 5 Oct 2016 18:15:05 +0200
Subject: [PATCH 13/13] Improve readability

---
 lib/output.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/output.js b/lib/output.js
index dd94fea5..ad2ccecb 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -138,8 +138,7 @@ function OutputStream(options) {
         var re = options.xml_safe ?
             /[\x00-\x1f\x22\x27\u2028\u2029\0\ud800-\udfff\ufeff\ufffe\uffff]/g :
             /[\\\b\f\n\r\v\t\x22\x27\u2028\u2029\0\ufeff]/g;
-        str = str.replace(re,
-          function(s, i){
+        str = str.replace(re, function(s, i){
             switch (s) {
               case '"': ++dq; return '"';
               case "'": ++sq; return "'";