avoid collision with HTML comments (#3625)

fixes #3624

1 files changed, 10 insertions, 29 deletions

diff --git a/lib/output.js b/lib/output.js
index 0f8ef1cd..d97778b2 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -269,7 +269,7 @@ function OutputStream(options) {
             }
         }
         newline_insert = -1;
-        var prev = last.charAt(last.length - 1);
+        var prev = last.slice(-1);
         if (might_need_semicolon) {
             might_need_semicolon = false;
 
@@ -298,16 +298,16 @@ function OutputStream(options) {
         }
 
         if (might_need_space) {
-            if ((is_identifier_char(prev)
-                    && (is_identifier_char(ch) || ch == "\\"))
+            if (is_identifier_char(prev) && (is_identifier_char(ch) || ch == "\\")
                 || (ch == "/" && ch == prev)
-                || ((ch == "+" || ch == "-") && ch == last))
-            {
+                || ((ch == "+" || ch == "-") && ch == last)
+                || str == "--" && last == "!"
+                || last == "--" && ch == ">") {
                 OUTPUT += " ";
                 current_col++;
                 current_pos++;
             }
-            might_need_space = false;
+            if (prev != "<" || str != "!") might_need_space = false;
         }
 
         if (mapping_token) {
@@ -322,7 +322,7 @@ function OutputStream(options) {
         }
 
         OUTPUT += str;
-        has_parens = str[str.length - 1] == "(";
+        has_parens = str.slice(-1) == "(";
         current_pos += str.length;
         var a = str.split(/\r?\n/), n = a.length - 1;
         current_line += n;
@@ -1254,29 +1254,10 @@ function OutputStream(options) {
         output.print(self.operator);
     });
     DEFPRINT(AST_Binary, function(self, output) {
-        var op = self.operator;
         self.left.print(output);
-        if (op[0] == ">" /* ">>" ">>>" ">" ">=" */
-            && self.left instanceof AST_UnaryPostfix
-            && self.left.operator == "--") {
-            // space is mandatory to avoid outputting -->
-            output.print(" ");
-        } else {
-            // the space is optional depending on "beautify"
-            output.space();
-        }
-        output.print(op);
-        if ((op == "<" || op == "<<")
-            && self.right instanceof AST_UnaryPrefix
-            && self.right.operator == "!"
-            && self.right.expression instanceof AST_UnaryPrefix
-            && self.right.expression.operator == "--") {
-            // space is mandatory to avoid outputting <!--
-            output.print(" ");
-        } else {
-            // the space is optional depending on "beautify"
-            output.space();
-        }
+        output.space();
+        output.print(self.operator);
+        output.space();
         self.right.print(output);
     });
     DEFPRINT(AST_Conditional, function(self, output) {